Matching entries: 0
settings...
AuthorTitleYearJournal/ProceedingsReftypeDOI/URL
Nishihara, T., Hoshino, T. & Tomita, M. Analysis of FCL effect caused by superconducting DC cables for railway systems [Abstract] [BibTeX] [PDF] 2017 IOP Conference Series: Materials Science and Engineering, Vol. 171(012122) Article DOI
Abstract: DC superconducting cable that is expected for railway system has been developed in the world, since the introduction effects were expected to energy saving. However, behaviour under unsteady states such as a short circuit accident are not entirely clear, and appropriate method of protection has not been established. Therefore, simulation model of the superconducting cable under direct current system was built and analyzed. Analysis result suggests the superconducting cable has the effect of Fault Current Limited (FCL) and critical current rise was effective method for temperature-rise suppression under unsteady states. Trade-off between cable temperature rise and overcurrent was confirmed.
BibTeX:
@inbook{Nishihara:p2017,
  author = {Taichi Nishihara and Tsutomu Hoshino and Masaru Tomita},
  title = {Analysis of FCL effect caused by superconducting DC cables for railway systems},
  journal = {IOP Conference Series: Materials Science and Engineering},

  year = {2017},
  month = {##feb##},
  volume = 171, 
  number=012122,  

  doi = {http://doi.org/10.1088/1757-899X/171/1/012122}
}
Nishihara, T., Hoshino, T. & Tomita, M. FCL Effect of DC Superconducting Cables in Unsteady State [Abstract] [BibTeX] [PDF] 2017 IEEE T. Appl. Supercon., Vol. 27(5400804) Article DOI
Abstract: DC superconducting cables for railway systems connected between substations have been developed. If the length of the superconducting cable is long enough, the superconducting cable is expected to have an effect of a resistive type fault current limiter (FCL) by the transition of the superconducting state and the normal state due to overcurrent than the critical current. Therefore, the simulation model of a direct current system with superconducting cables was constructed and the behavior of a superconducting cable was analyzed. And, there is a possibility of deterioration of critical current in a superconducting cable due to the aging and unexpected stresses since a superconducting cable is assumed to operate for long term. Then, the behavior of a deteriorated superconducting cable in the unsteady state was also analyzed. The analyzed results suggest that the 3000-m-long superconducting cable has the FCL effect and the temperature distribution assuming operation at liquid nitrogen does not affect the FCL effect. Furthermore, influence of the local deterioration, which has a potential to damage a superconducting cable in the unsteady state, could be estimated using this constructed model.
BibTeX:
@inbook{Nishihara:p2017a,
  author = {Taichi Nishihara and Tsutomo Hoshino and Masaru Tomita},
  title = {FCL Effect of DC Superconducting Cables in Unsteady State},
  journal = {IEEE Transactions on Applied Superconductivity},

  year = {2017},
  month = {##jun##},
  volume = 27, 
  number=5400804,  

  doi = {http://doi.org/10.1109/TASC.2017.2656632}
}
星野 勉 基本からわかる電気機器講義ノート [Abstract] [BibTeX] 2014 , pp. 35 - 74 Inbook URL
Abstract: 本書は、直流機、変圧器、誘導機、同期機の原理、特性、適用例といった、電気機器を学ぶ上で必須の基本事項について、ポイントを絞ってやさしくていねいにまとめた教科書・参考書です。電気機器の動作がイメージできるように、数式は最小限にして、詳細な図解と詳しい記述を心がけた解説としました。実際の講義であれば先生が適宜示す補足事項や内容理解のためのポイントを、“付せん"や“吹き出し"あるいは脚注を用いて随所に配してあるので、教科書としても、講義の予習・復習あるいは独習用の参考書としても最適な一冊です。 When learning an electrical appliance such as principles of direct-current machine, a transformer, a lead machine and a synchronous machine, the special qualities and application examples, this notes are the textbook and the reference book which narrowed a point down about an indispensable basic point and gathered politely easy. The numerical formula was made the explanation by which I made it minimal and provided for in-depth illustration and detailed description in order to imagine movement of an electrical appliance. The addition item a teacher shows accordingly when it's an actual lecture, and a point for the understanding of contents, using "tag" and "balloon" or a footnote, everywhere, it's distributed, so it's most suitable one as a textbook and as a reference book for preparation of a lecture, review or self-taught.
BibTeX:
@inbook{下村昭二2014,
  author = {星野 勉},
  title = {基本からわかる電気機器講義ノート},

  publisher = {オーム社},
  year = {2014},
  month = {aug},


  pages = {35 -- 74}, 
  url = {https://www.amazon.co.jp/%E5%9F%BA%E6%9C%AC%E3%81%8B%E3%82%89%E3%82%8F%E3%81%8B%E3%82%8B-%E9%9B%BB%E6%B0%97%E6%A9%9F%E5%99%A8%E8%AC%9B%E7%BE%A9%E3%83%8E%E3%83%BC%E3%83%88-%E4%B8%8B%E6%9D%91-%E6%98%AD%E4%BA%8C/dp/4274215768},
}
鷹野 致和, 星野 勉 & 大矢 博史 電子デバイスの絶縁性薄膜の信頼性評価法 [Abstract] [BibTeX] [PDF] 2011 ((A)2011-054674) Patent
Abstract: 電子デバイスの絶縁性薄膜の信頼性評価を行う方法を提供する。 The way to do the reliability assessment of the insulation film of an electronic device is offered.
BibTeX:
@inbook{Takano:2011,
  author = {鷹野 致和 and 星野 勉 and 大矢 博史},
  title = {電子デバイスの絶縁性薄膜の信頼性評価法},


  year = {2011},
  month = {mar},

  number=(A)2011-054674,  

}
鷹野 致和, 星野 勉 & 大矢 博史 電子デバイスの絶縁性薄膜の信頼性評価法 [Abstract] [BibTeX] [PDF] 2011 ((A)2011-053023) Patent
Abstract: Pool Frenkel障壁高さを求めることにより電子デバイスの絶縁件薄膜の信頼性評価を行う方法を提供する。 The way to do the reliability assessment of the insulation matter film of an electronic device by finding the Pool Frenkel barrier height is offered.
BibTeX:
@inbook{Takano:2011a,
  author = {鷹野 致和 and 星野 勉 and 大矢 博史},
  title = {電子デバイスの絶縁性薄膜の信頼性評価法},


  year = {2011},
  month = {mar},

  number=(A)2011-053023,  

}
星野 勉 限流器 [Abstract] [BibTeX] [PDF] 2010 (4469512) Patent
Abstract: 可変リアクトルをもつ整流型限流器について述べた The rectifier type current limiter with variable reactor was described.
BibTeX:
@inbook{Hoshino:2010,
  author = {星野 勉 and},
  title = {限流器},


  year = {2010},
  month = {may},

  number=4469512,  

}
Hamabe, M., Fujii, T., Yamamoto, I., Sasaki, A., Nasu, Y., Yamaguchi, S., Ninomiya, A., Hoshino, T., Ishiguro, Y. & Kawamura, K. Recent Progress of Experiment on DC Superconducting Power Transmission Line in Chubu University [Abstract] [BibTeX] [PDF] 2009 IEEE T. Appl. Supercond., Vol. 19(3), pp. 1778 - 1781 Article DOI
Abstract: A test stand of a DC superconducting power transmission cable was finished to construct in October 2006 in Chubu University, Japan, and three cooling cycles were carried out to measure the properties of the cable. Critical current of HTS tapes in the cable was measured at every cooling cycle and shows the similar temperature dependence; conclusively, the HTS tapes suffered no damage after cooling and heating process between the each cycle. Peltier current leads were partly installed in the test stand, and it was measured that the temperatures of the feedthrough near to the liquid nitrogen were decreased in spite of a current feeding.
BibTeX:
@inbook{Hamabe:j2009,
  author = {Hamabe, Makoto and Fujii, Tomohiro and Yamamoto, Isamu and Sasaki, Atsushi and Nasu, Yuji and Yamaguchi, Satarou and Ninomiya, Akira and Hoshino, Tsutomu and Ishiguro, Yasuhide and Kawamura, Kuniaki},
  title = {Recent Progress of Experiment on DC Superconducting Power Transmission Line in Chubu University},
  journal = {IEEE T. Appl. Supercond.},

  year = {2009},
  month = {June},
  volume = 19, 
  number=3,  
  pages = {1778 -- 1781}, 
  doi = {http://doi.org/10.1109/TASC.2009.2018241}
}
Yamaguchi, S., Hamabe, M., Yamamoto, I., Famakinwa, T., Sasaki, A., Iiyoshi, A., Schultz, J., Minervini, J., Hoshino, T., Ishiguro, Y. & Kawamura, K. Research activities of DC Superconducting Power Transmission Line in Chubu University [Abstract] [BibTeX] [PDF] 2008 J. Phys.: Conf. Ser., Vol. 97(012290), pp. 1 - 7 Article DOI
Abstract: A experiment of a DC Superconducting power transmission line using HTS conductor was started in Chubu University, Japan in autumn 2006. The first cooling down began in October 2006. The coolant is liquid nitrogen, and the cooling system used a cryogenic cooler and cold pump. The operation temperature is the range of 72 K - 80 K. The power cable has a total length of 20 m, and composed of thirty-nine Bi-2223 HTS tape conductors with critical current approximately100 A. The power cable achieved a 2.2 kA. The insulation voltage of the cable is 20 kV. In order to reduce the heat leakage and to avoid the current imbalance in the HTS tapes, we installed the Pelteir Current Lead (PCL) for each of the nineteen HTS tapes of the cable, with remaining twenty HTS tapes connected individually by the usual copper leads (CCL). Depending on the visual observation, and the measurement of temperatures of the current leads, the heat leakage of the PCL is lower than that of CCL. We installed a current transformer for each individual HTS tape conductor circuit, and measured the current of each HTS tape conductor. We measured the critical current of each HTS tape after the cable was installed into the cryostat, and degradation was not observed. Since the variation of the current in each tape is less than 10%, we eliminated the problem of current imbalance. Computational Fluid Dynamics is used to estimate the pressure drop, showing that the straight-tube cryostat has the advantage against the bellows- and corrugated-tube cryostats to reduce the pressure drop of the circulation of coolant. We proposed further to use the siphon for circulating the coolant in order to reduce the circulation losses and costs. We proposed that the voltage of the system be kept below 30 kV in order to use low cost power inverters. This choice can increase the storage energy of the power transmission line itself if we do not use a co-axial cable system because of it allows use of large current. And the magnetic energy of power grid is estimated to 4.5MJ/km for ±30 kA.
BibTeX:
@inbook{Yamaguchi:j2008,
  author = {Yamaguchi, Satarou and Hamabe, Makoto and Yamamoto, Isamu and Famakinwa, Tosin and Sasaki, Atsushi and Iiyoshi, Atsuo and Schultz, Joel and Minervini, Joe and Hoshino, Tsutomu and Ishiguro, Yasuhide and Kawamura, Kuniaki},
  title = {Research activities of DC Superconducting Power Transmission Line in Chubu University},
  journal = {J. Phys.: Conf. Ser.},

  year = {2008},
  month = {March},
  volume = 97, 
  number=012290,  
  pages = {1 -- 7}, 
  doi = {http://doi.org/10.1088/1742-6596/97/1/012290}
}
Wang, Z., Lü, S., Nakamura, T. & Hoshino, T. Study on the 1/$f^}$ Fluctuation of Botanic Potential [Abstract] [BibTeX] [PDF] 2007 AIP Conf. Proc.: Noise and Fluctuations: 19th International Conference on Noise and Fluctuations - ICNF 2007, Vol. 922, pp. 679 - 682 Article DOI
Abstract: In this paper, the 1/fα fluctuation property of the botanic potential time series is investigated in terms of wavelet spectrum and fractal dimension. It is shown that the signal exhibits the fluctuation characteristics investigated and the index is about alpha = 1.145, in addition, the fractal dimension is about D = 1.352±0.084.
BibTeX:
@inbook{Wang:j2007,
  author = {Wang, Zhaorui and Lü, Shanwei and Nakamura, Taketsune and Hoshino, Tsutomu},
  title = {Study on the 1/$f^{\alpha}$ Fluctuation of Botanic Potential},
  journal = {AIP Conf. Proc.: Noise and Fluctuations: 19th International Conference on Noise and Fluctuations - ICNF 2007},

  year = {2007},
  month = {July 11},
  volume = 922, 

  pages = {679 -- 682}, 
  doi = {http://doi.org/10.1063/1.2759767}
}
Chung, Y.-D., Hoshino, T. & Nakamura, T. Current Pumping Performance of Linear-Type Magnetic Flux Pump With Use of Feedback Control Circuit System [Abstract] [BibTeX] [PDF] 2006 IEEE T. Appl. Supercond., Vol. 16(2), pp. 1638 - 1641 Article DOI
Abstract: It has already been investigated that current pumping of the linear-type magnetic flux pump (LTMFP) is controlled by frequency of 3-phase inverter. In this paper, based on these operating characteristics, a current compensator, which is composed of a LTMFP and a feedback control circuit system, has been introduced to compensate for the persistent current decay of the superconducting magnet. From the experiment, the current compensator has been demonstrated with the toroidal assembly of six Nb-Ti magnets 543 mH under the operating load current at 10 A.
BibTeX:
@inbook{Chung:j2006,
  author = {Chung, Yoon-Do and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Current Pumping Performance of Linear-Type Magnetic Flux Pump With Use of Feedback Control Circuit System},
  journal = {IEEE T. Appl. Supercond.},

  year = {2006},
  month = {June 19},
  volume = 16, 
  number=2,  
  pages = {1638 -- 1641}, 
  doi = {http://doi.org/10.1109/TASC.2006.870452}
}
Nakamura, T., Miyake, H., Ogama, Y., Morita, G., Muta, I. & Hoshino, T. Fabrication and Characteristics of HTS Induction Motor by the Use of Bi-2223/Ag Squirrel-cage Rotor [Abstract] [BibTeX] [PDF] 2006 IEEE T. Appl. Supercond., Vol. 16(2), pp. 1469 - 1472 Article DOI
Abstract: HTS squirrel-cage induction motor was fabricated and tested in this study. Both of rotor bars and end rings were made of Bi-2223/Ag multifilamentary tapes in order to realize superconducting current loops, and the conventional (normal conducting) stator, 3-phase and 4-pole, was utilized. Rotating characteristics of the fabricated motor were tested for different input voltages at 60 Hz. The performances were also analyzed by means of the theoretical method based on the electrical equivalent circuit. It was shown that the minimum starting voltage was experimentally confirmed and agreed semi-quantitatively with the analysis result. The rotation at synchronous speed was realized by applying the load, at least, 1.5 Nm.
BibTeX:
@inbook{Nakamura:j2006,
  author = {Nakamura, Taketsune and Miyake, Hironori and Ogama, Yoshio and Morita, Gaku and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Fabrication and Characteristics of HTS Induction Motor by the Use of Bi-2223/Ag Squirrel-cage Rotor},
  journal = {IEEE T. Appl. Supercond.},

  year = {2006},
  month = {June 19},
  volume = 16, 
  number=2,  
  pages = {1469 -- 1472}, 
  doi = {http://doi.org//doi:10.1109/TASC.2005.864293}
}
Nakamura, T., Chung, Y.-D. & Hoshino, T. Magnetic Behaviour of Superconducting Foil Utilized for Linear-Type Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 2006 Studies in Applied Electromagnetics and Mechanics: Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering Proceedings of ISEF'05, Vol. 27, pp. 422-427 Inproceedings URL
Abstract: Magnetic behaviour of superconducting Nb foil, which is utilized for the proposed linear-type magnetic flux pump, was investigated based on 3D FEM analysis. The superconducting (nonlinear) J-E expressions were taken into account for the precise analysis. It was found that there exists the appropriate range of the DC bias current for the realisation of the travelling magnetic field. The value of the travelling magnetic flux was also found to be frequency dependent, and almost shielded over around 50 Hz. These findings are important for the optimal design of the superconducting flux pump for the compensation of the current decay in the superconducting magnets.
BibTeX:
@inbook{Nakamura:p2006,
  author = {Nakamura, Taketsune and Chung, Yoon-Do and Hoshino, Tsutomu},
  title = {Magnetic Behaviour of Superconducting Foil Utilized for Linear-Type Magnetic Flux Pump},


  year = {2006},

  volume = 27, 

  pages = {422-427}, 
  url = {http://www.booksonline.iospress.nl/Content/View.aspx?piid=4881},
}
星野 勉 大学をいきぬく方法 [Abstract] [BibTeX] [PDF] 2006 Book
Abstract: 大学で勉強する意欲を掻き立てる。
BibTeX:
@inbook{星野勉2006,
  author = {星野 勉},
  title = {大学をいきぬく方法},

  publisher = {明星大学理工学部},
  year = {2006},
  month = {apr},



}
Chung, Y.-D., Muta, I., Hoshino, T. & Nakamura, T. Characteristics of a Persistent Current Compensator for Superconducting NMR Magnets Using Linear Type Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 2005 IEEE T. Appl. Supercond., Vol. 15(2), pp. 1338 - 1341 Article DOI
Abstract: This paper describes the characteristics of a linear type magnetic flux pump for compensating current in a superconducting coil with 10 A operating current. The linear type flux pump has been fabricated to use for compensating persistent current decay of HTS applications such as NMR and MRI systems. Pumping current of the linear type magnetic flux pump mainly can be controlled by frequency of AC current. In the experiment, it has been demonstrated that the linear type magnetic flux pump can effectively charge and discharge the current in the load coil of 543 mH for various frequencies with the DC bias of 10 A and the AC of 5 Arms. Moreover, experimental results of temperature distribution of a slow response PCS have been compared with simulation.
BibTeX:
@inbook{Chung:j2005,
  author = {Chung, Yoon-Do and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Characteristics of a Persistent Current Compensator for Superconducting {NMR} Magnets Using Linear Type Magnetic Flux Pump},
  journal = {IEEE T. Appl. Supercond.},

  year = {2005},
  month = {June},
  volume = 15, 
  number=2,  
  pages = {1338 -- 1341}, 
  doi = {http://doi.org/10.1109/TASC.2005.849589}
}
Higashikawa, K., Nakamura, T. & Hoshino, T. Anisotropic Distributions of Current Density and Electric Field in Bi-2223/Ag Coil with Consideration of Multifilamentary Structure [Abstract] [BibTeX] [PDF] 2005 Physica C, Vol. 419, pp. 129 - 140 Article DOI
Abstract: Bi-2223/Ag double pancake coil with a stack number of 6 is analysed with the use of quantitative J–E expressions that can describe the magnetic anisotropy as well as temperature dependence of J–E curves in the tape. The practical multifilamentary structure of the tape is directly considered for the precise analysis. It is shown that the magnetic anisotropy greatly and complicatedly influences the distribution of the current density inside the tape as well as that of the electric field in the coil. Furthermore, the current transport performance of the coil is also shown to be largely influenced by the magnetic field generated by the coil itself.
BibTeX:
@inbook{Higashikawa:j2005a,
  author = {Higashikawa, Kohei and Nakamura, Taketsune and Hoshino, Tsutomu},
  title = {Anisotropic Distributions of Current Density and Electric Field in {Bi}-2223/{Ag} Coil with Consideration of Multifilamentary Structure},
  journal = {Physica C},
  publisher = {Elsevier},
  year = {2005},
  month = {March},
  volume = 419, 

  pages = {129 -- 140}, 
  doi = {http://doi.org/10.1016/j.physc.2004.12.012}
}
Higashikawa, K., Nakamura, T., Hoshino, T. & Muta, I. Design of Bi-2223/Ag Coil Based on Genetic Algorithm and Finite Element Method [Abstract] [BibTeX] [PDF] 2005 IEEE T. Appl. Supercond., Vol. 15(2), pp. 1895 - 1898 Article DOI
Abstract: We designed Bi-2223/Ag coils based on genetic algorithm and finite element method. The winding geometry as well as the operating current of the coil was optimized for the minimization of its loss, on condition that its operating temperature, stored energy and total length of the conductor were constant. The loss was calculated with the use of the analytical expressions that could quantitatively describe the current transport characteristics in high Tc superconductor including their magnetic anisotropy and temperature dependence. Some optimized results were shown and discussed in this paper.
BibTeX:
@inbook{Higashikawa:j2005b,
  author = {Higashikawa, Kohei and Nakamura, Taketsune and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Design of {Bi}-2223/{Ag} Coil Based on Genetic Algorithm and Finite Element Method},
  journal = {IEEE T. Appl. Supercond.},

  year = {2005},
  month = {June},
  volume = 15, 
  number=2,  
  pages = {1895 -- 1898}, 
  doi = {http://doi.org/10.1109/TASC.2005.849326}
}
Hoshino, T., Muta, I., Nakamura, T., Salim, K.M. & Yamada, M. Non-Inductive Variable Reactor Design and Computer Simulation of Rectifier Type Superconducting Fault Current Limiter [Abstract] [BibTeX] [PDF] 2005 IEEE T. Appl. Supercond., Vol. 15(2), pp. 2063 - 2066 Article DOI
Abstract: A rectifier type superconducting fault current limiter with noninductive reactor has been proposed by the authors. The concept behind this SFCL is that the high impedance generated during superconducting to normal state of the trigger coil limits the fault current. In the hybrid bridge circuit of the SFCL, two superconducting coils: a trigger coil and a limiting coil are connected in anti-parallel. Both the coils are magnetically coupled with each other and could have the same value of self inductance so that they can share the line current equally. At fault time when the trigger coil current reaches a certain level, the trigger coil changes from superconducting state to normal state. This super to normal transition of the trigger coil changes the current ratio of the coils and therefore the flux inside the reactor is no longer zero. So, the equivalent impedance of both the coils is increased and limits the fault current. We have carried out computer simulation using PSCAD/EMTDC and observed the results. Both the simulation and preliminary experiment shows good results. The advantage of using hybrid bridge circuit is that the SFCL can also be used as circuit breaker.
BibTeX:
@inbook{Hoshino:j2005,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Nakamura, Taketsune and Salim, Khosru Mohammad and Yamada, Masato},
  title = {Non-Inductive Variable Reactor Design and Computer Simulation of Rectifier Type Superconducting Fault Current Limiter},
  journal = {IEEE T. Appl. Supercond.},

  year = {2005},
  month = {June},
  volume = 15, 
  number=2,  
  pages = {2063 -- 2066}, 
  doi = {http://doi.org/10.1109/TASC.2005.849452}
}
Jung, H.-J., Nakamura, T., Miyake, H., Muta, I. & Hoshino, T. Preliminary Test Results of Radial-Type Sintered Sm-123 Bulk Motor [Abstract] [BibTeX] [PDF] 2005 IEEE T. Appl. Supercond., Vol. 15(2), pp. 2198 - 2201 Article DOI
Abstract: We designed and fabricated a radial-type motor with a high temperature superconducting bulk rotor. The fabricated motor has 3-phase and 4-pole armature winding, and then generates rotating magnetic field at the speed of 1800 rpm under the condition of 3-phase, 60 Hz electric power. Sintered Sm-123 bulk was utilized for the solid rotor in this study. The performance of the sintered Sm-123 bulk motor was evaluated by no-load, locked-rotor and load test. Test results showed that the motor generated a little torque and rotated with large slip, even if the motor was applied 165 Vrms of the phase voltage (the stator current is 18 Arms). Because of small magneto-motive-force and spatial harmonic components in the air-gap, magnetic flux was prevented from penetrating into the HTS bulk rotor. Therefore, the screening current in the rotor flowed only at the surface of the rotor and generated torque is remained in a little value.
BibTeX:
@inbook{Jung:j2005,
  author = {Jung, Hun-June and Nakamura, Taketsune and Miyake, Hironori and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Preliminary Test Results of Radial-Type Sintered {Sm}-123 Bulk Motor},
  journal = {IEEE T. Appl. Supercond.},

  year = {2005},
  month = {June},
  volume = 15, 
  number=2,  
  pages = {2198 -- 2201}, 
  doi = {http://doi.org/10.1109/TASC.2005.849611}
}
Nakamura, T., Kanzaki, H., Tsuboi, T., Higashikawa, K., Hoshino, T. & Muta, I. Analysis of Shielding Property in Bi-2223/Ag Multifilamentary Tapes with Multi-Layer Arrangement [Abstract] [BibTeX] [PDF] 2005 J. Mater. Process. Technol., Vol. 161(1-2), pp. 22 - 27 Article DOI
Abstract: Shielding property of Bi-2223/Ag multifilamentary tapes is analyzed based on the finite-element method. Quantitative expression of electric field versus current density, which is expressed as a function of temperature, magnetic field intensity and its applied direction, is taken into account. Detailed cross-sectional structure of the Bi-2223/Ag multifilamentary tape is also modeled for the precise analysis. It is shown that the power-law approximation of J–E curves (so-called n-value model) is inadequate to the analysis of the fault current condition. It is also to be reported that the shielding property of the multifilamentary tape is different from that of the monofilamentary tape. These results are crucial to the limit design of the HTS cable.
BibTeX:
@inbook{Nakamura:j2005a,
  author = {Nakamura, Taketsune and Kanzaki, Haruyuki and Tsuboi, Tsuneo and Higashikawa, Kohei and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Analysis of Shielding Property in {Bi}-2223/{Ag} Multifilamentary Tapes with Multi-Layer Arrangement},
  journal = {J. Mater. Process. Technol.},

  year = {2005},
  month = {April 10},
  volume = 161, 
  number=1-2,  
  pages = {22 -- 27}, 
  doi = {http://doi.org/10.1016/j.jmatprotec.2004.07.004}
}
Nakamura, T., Kanzaki, H., Higashikawa, K., Hoshino, T. & Muta, I. Analysis of Shielding Layers in HTS Cable Taking Account of Spiral Structure [Abstract] [BibTeX] [PDF] 2005 IEEE T. Appl. Supercond., Vol. 15(2), pp. 1747 - 1750 Article DOI
Abstract: Analysis code for shielding layers of HTS cable, which was taken account of spiral structure of Bi-2223/Ag tape conductors, was developed based on finite element method. The 66 kV class HTS cable, which was fabricated and successfully tested in cooperation of Tokyo Electric Power Co. (TEPCO) and Sumitomo Electric Industries, Ltd. (SEI), was subjected in this study. Electric field vs. current density property was expressed based on percolation depinning model (Yamafuji-Kiss model). Multifilamentary structure of the tapes and spiral structure of the conductors were directly modeled in order to analyze precisely. Systematic analysis results were presented and discussed.
BibTeX:
@inbook{Nakamura:j2005b,
  author = {Nakamura, Taketsune and Kanzaki, Haruyuki and Higashikawa, Kohei and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Analysis of Shielding Layers in {HTS} Cable Taking Account of Spiral Structure},
  journal = {IEEE T. Appl. Supercond.},

  year = {2005},
  month = {June},
  volume = 15, 
  number=2,  
  pages = {1747 -- 1750}, 
  doi = {http://doi.org/10.1109/TASC.2005.849272}
}
Balamurugan, S., Nakamura, T., Osamura, K., Muta, I. & Hoshino, T. Annealing Effects on Structural and Superconducting Properties of MgB$_2$/Fe Wires [Abstract] [BibTeX] [PDF] 2004 Mod. Phys. Lett. B, Vol. 18(16), pp. 791 - 802 Article DOI
Abstract: We report the results of annealing effects on structural and superconducting properties (T-c and J(c)) of various MgB2/Fe wires that are produced by different conditions. Good quality superconducting MgB2/Fe wires are fabricated by the powder-in-tube (PIT) technique at ambient pressure. XRD data confirms that they are hexagonal MgB2 structure. All the annealed samples show higher T-c values in the range of 34.6-38.4 K with J(c) higher than the as-rolled wire. The annealed samples show significant change in the J(c) values as well as in micro-structural features due to variable sintering temperature. On annealing at 1050degreesC for 10 min, we obtain the best quality sample with a J(c) of 37.2 kA/cm(2) at 33.1 K and self-field with a maximum T-c of 38.4 K. Among the samples annealed at 1050degreesC for 5-20 min, the 20 min sample shows lower J(c). Longer annealing time (at 1050degreesC) reduced J(c), indicating a possible interfacial reaction between the Fe sheath and the MgB2 core.
BibTeX:
@inbook{Balamurugan:j2004,
  author = {Balamurugan, Sarkarainadar and Nakamura, Taketsune and Osamura, Kozo and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Annealing Effects on Structural and Superconducting Properties of {MgB}$_{2}$/{Fe} Wires},
  journal = {Mod. Phys. Lett. B},
  publisher = {World Scientific Publ. Co. PTE Ltd},
  year = {2004},
  month = {July~10},
  volume = 18, 
  number=16,  
  pages = {791 - 802}, 
  doi = {http://doi.org/10.1142/S0217984904007323}
}
Balamurugan, S., Nakamura, T., Osamura, K., Muta, I. & Hoshino, T. Structural and Superconducting Properties of PIT Processed Sintered MgB$_2$/Fe Wires [Abstract] [BibTeX] [PDF] 2004 Physica C, Vol. 412-414, pp. 1184 - 1188 Article DOI
Abstract: In this paper, we report the structural and superconducting properties of MgB2/Fe wires that are produced by different sintering conditions. Good quality MgB2/Fe wires are fabricated by the powder-in-tube (PIT) method using commercially available MgB2 powder at ambient pressure. In order to check the annealing effect, the different pieces of the as-rolled wires are sintered at 1323 K for 0.30–1.20 ks. XRD data confirms that they are hexagonal MgB2 structure. All the sintered samples show higher Tc values in the range of 38.2–38.4 K with high Jc than the as-rolled sample. No significant change in Tc is seen among the annealed samples. On the other hand, the annealed samples show significant change in the Jc values as well as in micro-structural features due to variable sintering time. On annealing at 1323 K for 0.60 ks, we obtain the best quality sample with a Jc of 372 A/mm2 at 33.1 K in self-field with a maximum Tc of 38.4 K. Among the annealed samples, 1.20 ks sample shows lower Jc. Longer annealing time reduced Jc, indicating a possible interfacial reaction between the Fe sheath and the MgB2 core.
BibTeX:
@inbook{Balamurugan:j2004a,
  author = {Balamurugan, Sarkarainadar and Nakamura, Taketsune and Osamura, Kozo and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Structural and Superconducting Properties of {PIT} Processed Sintered {MgB$_{2}$/Fe} Wires},
  journal = {Physica C},
  publisher = {Elsevier},
  year = {2004},
  month = {October},
  volume = 412-414, 

  pages = {1184 - 1188}, 
  doi = {http://doi.org/10.1016/j.physc.2004.05.001}
}
Chung, Y.-D., Muta, I., Hoshino, T. & Nakamura, T. Performances of a Linear Type Magnetic Flux Pump for Compensating a Little Decremented Persistent Current of HTS Magnets [Abstract] [BibTeX] [PDF] 2004 IEEE T. Appl. Supercond., Vol. 14(2), pp. 1723 - 1726 Article DOI
Abstract: This paper describes the characteristics of a linear type magnetic flux pump recently developed. The linear type flux pump has been fabricated to apply to compensate decremented persistent current of HTS applications such as NMR and MRI system. The linear type magnetic flux pump mainly consists of 3-phase AC armature coil, DC bias coil and superconducting Nb foil. In the preliminary experiment, the flux pump can charge the pumping-up current in the load coil of 1.3 mH during 1000 seconds under the DC bias current of 10 A and 3-phase AC of 8 A, 60 Hz. The magnitude of pumping current is 0.1 mA/s.
BibTeX:
@inbook{Chung:j2004,
  author = {Chung, Yoon-Do and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Performances of a Linear Type Magnetic Flux Pump for Compensating a Little Decremented Persistent Current of {HTS} Magnets},
  journal = {IEEE T. Appl. Supercond.},
  publisher = {IEEE Inc.},
  year = {2004},
  month = {June},
  volume = 14, 
  number=2,  
  pages = {1723 - 1726}, 
  doi = {http://doi.org/10.1109/TASC.2004.831054}
}
Chung, Y.-D., Muta, I., Hoshino, T., Nakamura, T. & Sohn, M.-H. Design and Performance of Compensator for Decremental Persistent Current in HTS Magnets Using Linear Type Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 2004 Cryogenics, Vol. 44(11), pp. 839 - 844 Article DOI
Abstract: This paper has described the characteristics of a stationary linear type magnetic flux pump newly developed this time. The linear type flux pump aims to compensate a little decremental persistent current of the HTS magnet in NMR and MRI systems. The flux pump mainly consists of DC bias coil, 3-phase AC coil and Nb foil. Analytical results by the FEM are proved to nearly agree with experimental ones. In the experiment, it has been investigated that the flux pump can effectively charge the current in the load coil of 1.3 mH for various frequencies in 150 s under two following conditions: (1) DC bias of 10 A and AC of 4 A(rms), (2) DC bias of 10 A and AC of 5 A(rms). The maximum magnitudes of initial increasing rate of pumping current and load magnet voltage are: (1) 0.2 A/s and 25 mV and (2) 0.22 A/s and 34 mV, respectively.
BibTeX:
@inbook{Chung:j2004a,
  author = {Chung, Yoon-Do and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Sohn, Myung-Hwan},
  title = {Design and Performance of Compensator for Decremental Persistent Current in {HTS} Magnets Using Linear Type Magnetic Flux Pump},
  journal = {Cryogenics},

  year = {2004},
  month = {November},
  volume = 44, 
  number=11,  
  pages = {839 - 844}, 
  doi = {http://doi.org/10.1016/j.cryogenics.2004.06.001}
}
Chung, Y.-D., Muta, I., Hoshino, T., Nakamura, T. & Ko, T. Pumping-up Current Characteristics of Linear Type Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 2004 J. Korea Inst. Appl. Supercond. Cryog. Inst., Vol. 6(2), pp. 29 - 34 Article URL
Abstract: The linear type flux pump aims to compensate a little bit decremental persistent current of the HTS magnet in NMR and MRI spectrometers. The flux pump mainly consists of DC bias coil, 3-phase AC coil and Nb foil. The persistent current in closed superconductive circuit can be easily adjusted by the 3-phase AC current, its frequency and the DC bias current. In the experiment, it has been investigated that the flux pump can effectively charge the current in the load coil of 543 mH for various frequencies in 18 minutes under the DC bias of 10 A and the AC of 5 . The maximum magnitudes of pumping current and load magnet voltage are 0.72 A/min and 20 mV, respectively. Based on simulation results by the FEM are proved to nearly agree with experimental ones.
BibTeX:
@inbook{Chung:j2004b,
  author = {Chung, Yoon-Do and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Ko, Taekuk},
  title = {Pumping-up Current Characteristics of Linear Type Magnetic Flux Pump},
  journal = {J. Korea Inst. Appl. Supercond. Cryog. Inst.},

  year = {2004},
  month = {March},
  volume = 6, 
  number=2,  
  pages = {29 - 34}, 
  url = {http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=CJJOCB_2004_v6n2_29},
}
Han, S.-I., Muta, I., Hoshino, T., Nakamura, T. & Maki, N. Optimal Design of Superconducting Generator Using Genetic Algorithm and Simulated Annealing [Abstract] [BibTeX] [PDF] 2004 IEE Proc.-Electr. Power Appl., Vol. 151(5), pp. 543 - 554 Article DOI
Abstract: A method for the design of superconducting generator using multiobjective optimization technique based on genetic algorithm is described in this paper. In consideration of electrical and mechanical characteristics of superconducting generator, efficiency and specific power of superconducting generator are optimized, respectively, and to find the best compromise solution between efficiency and specific power, multiobjective optimization is implemented. The results of the optimally designed superconducting generator show the reduction of dimension and loss, compared with those of 70MW class superconducting generator already developed in Japan, and therefore they demonstrate the effectiveness of the design method. 1.
BibTeX:
@inbook{Han:j2004,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Maki, Naoki},
  title = {Optimal Design of Superconducting Generator Using Genetic Algorithm and Simulated Annealing},
  journal = {IEE Proc.-Electr. Power Appl.},
  publisher = {IEE-Inst. Elec. Eng.},
  year = {2004},
  month = {September},
  volume = 151, 
  number=5,  
  pages = {543 - 554}, 
  doi = {http://doi.org/10.1049/ip-epa:20040352}
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. An Approach of Optimal Design of HTS Synchronous Motor Using Genetic Algorithm [Abstract] [BibTeX] [PDF] 2004 IEEE T. Appl. Supercond., Vol. 14(2), pp. 896 - 899 Article DOI
Abstract: This paper describes an optimal design of 100 HP, 4 pole, 1800 rpm High Temperature Superconducting (HTS) synchronous motor in terms of energy efficiency and downsizing, i.e., specific power density. Bi-2223/Ag multifilamentary tape is used as a material of HTS field coil. Design variables and constraints are appropriately set up in consideration of electromagnetic characteristics. Size of the rotor and the stator is calculated with fundamental expressions based on the two-dimensional electromagnetic analysis. As an optimization technique to obtain the dimension of optimal specific power density or energy efficiency of the HTS motor, genetic algorithm (GA) which is well-known as aglobal optimal technique modeled on the concept of natural selection and evolution has been used. Electrical characteristics such as efficiency and V-curve for the HTS motor optimally designed are also investigated.
BibTeX:
@inbook{Han:j2004a,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {An Approach of Optimal Design of {HTS} Synchronous Motor Using Genetic Algorithm},
  journal = {IEEE T. Appl. Supercond.},

  year = {2004},
  month = {June},
  volume = 14, 
  number=2,  
  pages = {896 - 899}, 
  doi = {http://doi.org/10.1109/TASC.2004.830312}
}
Higashikawa, K., Nakamura, T., Muta, I. & Hoshino, T. Investigation of Dissipative Behaviour in Bi-2223/Ag Coil with Consideration of Multifilamentary Structure [BibTeX] [PDF] 2004 J. Phys.: Conf. Ser. : Proc. 6th EUCASJ. Phys.: Conf. Ser. : Proc. 6th EUCAS, Vol. 181, pp. 611 - 616 Inproceedings URL
Abstract:
BibTeX:
@inbook{Higashikawa:p2004a,
  author = {Higashikawa, Kohei and Nakamura, Taketsune and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Investigation of Dissipative Behaviour in {Bi}-2223/{Ag} Coil with Consideration of Multifilamentary Structure},
  journal = {J. Phys.: Conf. Ser. : Proc. 6th EUCAS},
  publisher = {CRC Press},
  year = {2004},
  month = {December},
  volume = 181, 

  pages = {611 - 616}, 
  url = {https://www.crcpress.com/Applied-Superconductivity-2003-Proceedings-of-the-6th-European-Conference/Andreone-Pepe-Cristiano-Masullo/p/book/9780750309813},
}
Hoshino, T., Salim, K.M., Muta, I., Nakamura, T. & Yamada, M. Experiment Using Variable Reactor of Rectifier Type Superconducting Fault Current Limiter with a Short-Circuited Trigger Coil [Abstract] [BibTeX] [PDF] 2004 IEEE T. Appl. Supercond., Vol. 14(2), pp. 626 - 629 Article DOI
Abstract: A rectifier type superconducting fault current limiter using an additional shot-circuited trigger coil has been studied. Such reactor consists of two well-coupled superconducting coils; the main coil and trigger coil. The main coil is connected to the DC link of the bridge circuit while the trigger winding is always short-circuited. As the trigger coil is short-circuited the reactor shows low inductance in normal operation. A change of load current due to load change or some other reasons increase the shot-circuit current but inductance value remains unchanged as long as the trigger coil remains in superconducting state. During fault time, the fault current yields super to normal transition current in the secondary (trigger) winding and the trigger coil quenches. Thus higher impedance appears in the main coil that limits the fault current. The advantage of using an additional trigger coil with the main coil is that it reduces the impedance of the current limiter at normal operation and therefore reduces voltage drop across the limiter. To enhance the coupling factor of the windings iron core can be used. If the magnetic path is closed with the iron core even with some air gap it can be saturated during fault time because of the high DC current but would effectively reduce leakage reactance during normal operation. In this paper a small-scale experimental result of this type of current limiter has been presented.
BibTeX:
@inbook{Hoshino:j2004,
  author = {Hoshino, Tsutomu and Salim, Khosru Mohammad and Muta, Itsuya and Nakamura, Taketsune and Yamada, Masato},
  title = {Experiment Using Variable Reactor of Rectifier Type Superconducting Fault Current Limiter with a Short-Circuited Trigger Coil},
  journal = {IEEE T. Appl. Supercond.},

  year = {2004},
  month = {June},
  volume = 14, 
  number=2,  
  pages = {626 - 629}, 
  doi = {http://doi.org/10.1109/TASC.2004.830003}
}
Jo, Y.-S., Nakamura, T., Hoshino, T., Chung, Y.-D., Hong, J.-P. & Kwon, Y.-K. Characteristic Study and Three Dimensional Magnetic Field Analysis of the Superconducting Synchronous Machine [Abstract] [BibTeX] [PDF] 2004 Physica C, Vol. 416, pp. 108 - 114 Article DOI
Abstract: The field distribution analysis and the characterization of racetrack magnet for LTS (low temperature superconductor) generator and HTS (high temperature superconductor) motor were performed. An SSM (superconducting synchronous machine) have two structural characteristics: they have similar air-cored structures which function to avoid saturation at an iron-core; the process of keeping superconductor cold and insulated leads to a long air-gap length. For those reasons, the SSM is featured by three dimensional (3D) magnetic flux distribution, which varies in the direction of axis. An analytical method to analyze more fast and accurately the effect of the shape of the field coil on the 3D magnetic field distribution, was studied. The 3D magnetic field distribution of the SSM (LTS generator and HTS motor) was calculated using the analytical method, and then the results were verified by experiment and 3D finite element method (FEM).
BibTeX:
@inbook{Jo:j2004,
  author = {Jo, Young-Sik and Nakamura, Taketsune and Hoshino, Tsutomu and Chung, Yoon-Do and Hong, Jung-Pyo and Kwon, Young-Kil},
  title = {Characteristic Study and Three Dimensional Magnetic Field Analysis of the Superconducting Synchronous Machine},
  journal = {Physica C},
  publisher = {Elsevier},
  year = {2004},
  month = {December 1},
  volume = 416, 

  pages = {108 - 114}, 
  doi = {http://doi.org/10.1016/j.physc.2004.09.004}
}
Jung, H.-J., Nakamura, T., Tanaka, N., Muta, I. & Hoshino, T. Characteristic Analysis of Hysteresis-Type Bi-2223 Bulk Motor with the Use of Equivalent Circuit [Abstract] [BibTeX] [PDF] 2004 Physica C, Vol. 405(2), pp. 117 - 126 Article DOI
Abstract: Characteristics of a hysteresis-type Bi-2223 bulk motor were studied based on the equivalent circuit. The Bi-2223 bulk motor consists of a disk shaped Bi-2223 bulk rotor and a 3-phase, 4-pole stator. The locked-rotor test results were discussed in this study. Stator impedance was directly obtained through the measurement, and then the rotor resistance was estimated from the equivalent circuit with some assumptions. In order to show the validity of the equivalent circuit, the experimental results were compared with the calculated results using the circuit. It was shown that the calculated results of the torque curves agree semi-quantitatively with the experimental results. Based on the equivalent circuit, temperature dependence of the rotor resistance is also to be presented and discussed.
BibTeX:
@inbook{Jung:j2004,
  author = {Jung, Hun-June and Nakamura, Taketsune and Tanaka, Nobuyuki and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Characteristic Analysis of Hysteresis-Type {Bi}-2223 Bulk Motor with the Use of Equivalent Circuit},
  journal = {Physica C},

  year = {2004},
  month = {June~1},
  volume = 405, 
  number=2,  
  pages = {117 - 126}, 
  doi = {http://doi.org/10.1016/j.physc.2004.01.031}
}
牟田 一彌, 星野 勉, 中村 武恒 & Salim, K.M. 限流装置 [Abstract] [BibTeX] [PDF] 2004 ((A)2004-274863) Patent
Abstract: 可飽和直流リアクトル型限流器について述べた The saturable direct-current reactor type current limiter was described.
BibTeX:
@inbook{Muta:2004,
  author = {牟田 一彌 and 星野 勉 and 中村 武恒 and Khosru Mohammad Salim},
  title = {限流装置},


  year = {2004},
  month = {mar},

  number=(A)2004-274863,  

}
Muta, I., Hoshino, T., Salim, K.M., Kawasaki, A., Nakamura, T. & Yamada, M. Proposal of DC Shield Reactor Type Superconducting Fault Current Limiter [Abstract] [BibTeX] [PDF] 2004 Cryogenics, Vol. 44(3), pp. 177 - 182 Article DOI
Abstract: Saturated DC reactor type superconducting fault current limiter (SFCL) had been proposed two years ago. It was classified to rectifier type SFCL. The changing inductance value with the operating mode has superior characteristics to reduce voltage sag during step increase of the load current. But it has the disadvantage of its weight. In this paper, rectifier type SFCL with shielded reactor has been proposed. The reactor which has superconducting ring or tube inside its winding is substituted to the DC link of the rectifier. The configuration looks like an air core transformer with secondary short winding. When the current through the bulk shield-ring reaches to a certain level, the flux penetrates to the shield body and finite impedance appears in the primary winding. In other words, when the surface flux density exceeds its critical flux density, the flux penetrates into the bulk superconductor, and increases equivalent inductance. The equivalent transient resistance of the shield was represented as a function of exponential of the time. Using this equivalent transient resistance, the transient impedance was expressed. The transient wave analysis using EMTDC (electro-magnetic transients in DC systems) has been described. Simulated waveforms are shown considering the source inductance, the leakage inductance, the coupling coefficient and the forward voltage drop of the semiconductor. And voltage sag was also investigated with 50\% step load increase. Preliminary design was also performed. The coil size and number of turns are designed to obtain adequate inductance for the current limitation, and the central magnetic field of the coils are calculated. There is optimal aspect ratio to minimize the magnetic field with restriction in outer diameter of the coil.
BibTeX:
@inbook{Muta:j2004,
  author = {Muta, Itsuya and Hoshino, Tsutomu and Salim, Khosru Mohammad and Kawasaki, Akio and Nakamura, Taketsune and Yamada, Masato},
  title = {Proposal of {DC} Shield Reactor Type Superconducting Fault Current Limiter},
  journal = {Cryogenics},

  year = {2004},
  month = {March},
  volume = 44, 
  number=3,  
  pages = {177 - 182}, 
  doi = {http://doi.org/10.1016/j.cryogenics.2003.10.004}
}
Nakamura, T., Higashikawa, K., Muta, I. & Hoshino, T. Performance of Conduction-Cooled HTS Tape with the Aid of Solid Nitrogen-Liquid Neon Mixture [Abstract] [BibTeX] [PDF] 2004 Physica C, Vol. 412-414, pp. 1221 - 1224 Article DOI
Abstract: We study the new-type of cryogen, which consists of solid nitrogen and liquid neon, for the performance improvement of the HTS application systems. Bi-2223/Ag multifilamentary tape is impregnated with the solid nitrogen–liquid neon mixture, and the temperature at the surface of the tape is measured by applying the overcurrent. The cryogen is produced by the GM cryocooler, and the initial temperature is set to be 25.1 K. It is shown that the thermal behavior of the tape is improved drastically by impregnating with the mixture compared to the solid nitrogen alone. The reason for this result can be explained that the heat generated in the tape is transferred by the liquid neon to the solid nitrogen. Therefore, the proposed mixture is important for the conduction cooled HTS coil applications such as SMES. A detailed explanation of the experiments is presented in this paper.
BibTeX:
@inbook{Nakamura:j2004,
  author = {Nakamura, Taketsune and Higashikawa, Kohei and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Performance of Conduction-Cooled {HTS} Tape with the Aid of Solid Nitrogen-Liquid Neon Mixture},
  journal = {Physica C},
  publisher = {Elsevier},
  year = {2004},
  month = {October},
  volume = 412-414, 

  pages = {1221 - 1224}, 
  doi = {http://doi.org/10.1016/j.physc.2003.12.085}
}
Nakamura, T., Jung, H.-J., Muta, I. & Hoshino, T. Synchronization of an Axial-Type Bi-2223 Bulk Motor Operated in Liquid Nitrogen [Abstract] [BibTeX] [PDF] 2004 Supercond. Sci. Technol., Vol. 17(11), pp. 1319 - 1323 Article DOI
Abstract: We fabricated and tested an axial-type Bi-2223 bulk motor that was operated in liquid nitrogen. The rotating characteristics were tested as a function of temperature, which was controlled by evacuating the metal cryostat with a rotary vacuum pump. The tests were performed for different air-gap lengths. It was found for the first time that the synchronization was realized when the operating temperature as well as the armature current was set to the appropriate range. Furthermore, the no-load test results showed that the rotating speed had no hysteretic characteristics through the increasing and decreasing process of the armature current even after the motor was pulled-in, and this result indicated that there were no trapped fluxoids in the bulk rotor.
BibTeX:
@inbook{Nakamura:j2004a,
  author = {Nakamura, Taketsune and Jung, Hun-June and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Synchronization of an Axial-Type {Bi}-2223 Bulk Motor Operated in Liquid Nitrogen},
  journal = {Supercond. Sci. Technol.},

  year = {2004},
  month = {November},
  volume = 17, 
  number=11,  
  pages = {1319 - 1323}, 
  doi = {http://doi.org/10.1088/0953-2048/17/11/013}
}
Nakamura, T., Jung, H.-J., Muta, I. & Hoshino, T. Steady State Characteristics of Axial-type Sm-123 Bulk Motor under Different Synchronous Speed [BibTeX] [PDF] 2004 Institute of Physics Conference Series, Vol. 181, Applied Superconductivity 2003: Proceedings of the 6th EUCAS, Sorrento, Italy, 14-18 September 2003Applied Superconductivity 2003: Proc.6th EUCAS, Sorrento, Italy, 14-18 September 2003, Vol. 181, pp. 867 - 870 Inproceedings URL
Abstract:
BibTeX:
@inbook{Nakamura:p2004b,
  author = {Nakamura, Taketsune and Jung, Hun-June and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Steady State Characteristics of Axial-type {Sm}-123 Bulk Motor under Different Synchronous Speed},
  journal = {Institute of Physics Conference Series, Vol. 181, Applied Superconductivity 2003: Proceedings of the 6th EUCAS, Sorrento, Italy, 14-18 September 2003},

  year = {2004},
  month = {December},
  volume = 181, 

  pages = {867 - 870}, 
  url = {https://www.crcpress.com/Applied-Superconductivity-2003-Proceedings-of-the-6th-European-Conference/Andreone-Pepe-Cristiano-Masullo/p/book/9780750309813},
}
Nakamura, T., Jung, H.-J., Muta, I. & Hoshino, T. Relationship between Magnetization Characteristics and Torque Mechanism in High Temperature Superconducting Bulk Motor [BibTeX] [PDF] 2004 Proc.ICEM'04, Vol. 3, pp. 967 - 970 Inproceedings
Abstract:
BibTeX:
@inbook{Nakamura:p2004d,
  author = {Nakamura, Taketsune and Jung, Hun-June and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Relationship between Magnetization Characteristics and Torque Mechanism in High Temperature Superconducting Bulk Motor},


  year = {2004},
  month = {September 8},
  volume = 3, 

  pages = {967 -- 970}, 
}
Salim, K.M., Muta, I., Hoshino, T., Nakamura, T. & Yamada, M. Proposal of Rectifier Type Superconducting Fault Current Limiter with Non-Inductive Reactor (SFCL) [Abstract] [BibTeX] [PDF] 2004 Cryogenics, Vol. 44(3), pp. 171 - 176 Article DOI
Abstract: A rectifier type superconducting fault current limiter (SFCL) with non-inductive reactor has been proposed. The concept behind this SFCL is the appearance of high impedance during non-superconducting state of the coil. In a hybrid bridge circuit, two superconducting coils connected in anti-parallel: a trigger coil and a limiting coil. Both the coils are magnetically coupled with each other and have same number of turns. There is almost zero flux inside the core and therefore the total inductance is small during normal operation. At fault time when the trigger coil current reaches to a certain level, the trigger coil changes from superconducting state to normal state. This super-to-normal transition of the trigger coil changes the current ratio of the coils and therefore the flux inside the reactor is no longer zero. So, the equivalent impedance of both the coils increased thus limits the fault current. We have carried out computer simulation using EMTDC and observed the results. A preliminary experiment has already been performed using copper wired reactor with simulated super-to-normal transition resistance and magnetic switches. Both the simulation and preliminary experiment shows good results. The advantage of using hybrid bridge circuit is that the SFCL can also be used as circuit breaker. Two separate bridge circuit can be used for both trigger coil and the limiter coil. In such a case, the trigger coil can be shutdown immediately after the fault to reduce heat and thus reduce the recovery time. Again, at the end of fault when the SFCL needs to re-enter to the grid, turning off the trigger circuit in the two-bridge configuration the inrush current can be reduced. This is because the current only flows through the limiting coil. Another advantage of this type of SFCL is that no voltage sag will appear during load increasing time as long as the load current stays below the trigger current level. (C) 2003 Elsevier Ltd. All rights reserved.
BibTeX:
@inbook{Salim:j2004,
  author = {Salim, Khosru Mohammad and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Yamada, Masato},
  title = {Proposal of Rectifier Type Superconducting Fault Current Limiter with Non-Inductive Reactor ({SFCL})},
  journal = {Cryogenics},

  year = {2004},
  month = {March},
  volume = 44, 
  number=3,  
  pages = {171 - 176}, 
  doi = {http://doi.org/10.1016/j.cryogenics.2003.10.005}
}
Salim, K.M., Hoshino, T., Muta, I., Nakamura, T. & Yamada, M. Low Voltage Test of a Single Bridge Rectifier Type Superconducting Fault Current Limiter with Non-Inductive Reactor [BibTeX] [PDF] 2004 Institute of Physics Conference Series, Vol. 181, Applied Superconductivity 2003: Proceedings of the 6th EUCAS, Sorrento, Italy, 14-18 September 2003Applied Superconductivity 2003: Proceedings of the 6th EUCAS, Sorrento, Italy, 14-18 September 2003, Vol. 181, pp. 811-818 Inproceedings URL
Abstract:
BibTeX:
@inbook{Salim:p2004,
  author = {Salim, Khosru Mohammad and Hoshino, Tsutomu and Muta, Itsuya and Nakamura, Taketsune and Yamada, Masato},
  title = {Low Voltage Test of a Single Bridge Rectifier Type Superconducting Fault Current Limiter with Non-Inductive Reactor},
  journal = {Institute of Physics Conference Series, Vol. 181, Applied Superconductivity 2003: Proceedings of the 6th EUCAS, Sorrento, Italy, 14-18 September 2003},

  year = {2004},
  month = {December},
  volume = 181, 

  pages = {811-818}, 
  url = {https://www.crcpress.com/Applied-Superconductivity-2003-Proceedings-of-the-6th-European-Conference/Andreone-Pepe-Cristiano-Masullo/p/book/9780750309813},
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. 200 MW Class Superconducting Generator Design by Use of GA [BibTeX] [PDF] 2003 Proc.ICEEProc.ICEE, Vol. 11(ICEE-119), pp. 1 - 6 Inproceedings
Abstract:
BibTeX:
@inbook{Han:p2003,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {200 {MW} Class Superconducting Generator Design by Use of {GA}},
  journal = {Proc.ICEE},

  year = {2003},
  month = {July~6-10},
  volume = 11, 
  number=ICEE-119,  
  pages = {1 -- 6}, 
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. An Approach for Genetic Algorithm Aided Design of Superconducting Generator [BibTeX] [PDF] 2003 Proc. 2003 ICEMS (ICEMS2003), Vol. 1(PS-2-14), pp. 141 - 145 Inproceedings DOI URL
Abstract:
BibTeX:
@inbook{Han:p2003a,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {An Approach for Genetic Algorithm Aided Design of Superconducting Generator},

  publisher = {IEEE},
  year = {2003},
  month = {November9-11},
  volume = 1, 
  number=PS-2-14,  
  pages = {141 -- 145}, 
  url = {http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1273831},
  doi = {http://doi.org/10.1109/ICEMS.2003.1273831}
}
Hoshino, T., Salim, K.M., Kawasaki, A., Muta, I., Nakamura, T. & Yamada, M. Design of 6.6 kV, 100 A Saturated DC Reactor Type Superconducting Fault Current Limiter [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 2012 - 2015 Article DOI
Abstract: Proposed saturated DC reactor type superconducting fault current limiter (SFCL) was designed and fabricated. The rated value was 100 V and 10 A for small scale experiment. The relationships between the one-turn voltage and the cross section of the core, the inductance value are obtained, The optimized cross section of the core was 90 mm x 45 mm under restriction of the core manufacturer. The core material was ultra fine grain steel named FINEMET(R) FT-3H. The number of main winding was 100 turn and that of control winding was also 100 turn. The wires are NbTi superconductor with different filament diameter. We enhanced this design scheme to 6.6 kV, 100 A SFCL. The core cross section size and core gap and core length of 6.6 kV design are presented.
BibTeX:
@inbook{Hoshino:j2003,
  author = {Hoshino, Tsutomu and Salim, Khosru Mohammad and Kawasaki, Akio and Muta, Itsuya and Nakamura, Taketsune and Yamada, Masato},
  title = {Design of 6.6 {kV}, 100 {A} Saturated {DC} Reactor Type Superconducting Fault Current Limiter},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {2012 - 2015}, 
  doi = {http://doi.org/10.1109/TASC.2003.812967}
}
Jang, H.-M., Muta, I., Hoshino, T., Nakamura, T., Kim, S.-W., Sohn, M.-H., Kwon, Y.-K. & Ryu, K.-S. Design and Electrical Characteristics, Analysis of 100 HP HTS Synchronous Motor in 21st Century Frontier Project, Korea [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 2197 - 2200 Article DOI
Abstract: A 100 hp class superconducting motor in the 21st Century Frontier R&D Program of Korea has been designed. A theoretical model of high temperature superconducting (HTS) motor was presented by two-dimensional electromagnetic field analysis. The motor is. composed of HTS field winding, cold damper shield, air-gap armature winding and laminated machine shield. The HTS field winding consists of racetrack type double pancake coils Wound with Bi-2223 HTS tapes operated at about 30 K. The operating current of the HTS tape conductor could be determined by the magnetic field distribution calculated in the HTS field winding and the I-c-B characteristics of a practical HTS conductor, taking account of its anisotropy.
BibTeX:
@inbook{Jang:j2003,
  author = {Jang, Hyun-Man and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Kim, Seog-Whan and Sohn, Myung-Hwan and Kwon, Young-Kil and Ryu, Kang-Sik},
  title = {Design and Electrical Characteristics, Analysis of 100 {HP} {HTS} Synchronous Motor in 21st Century Frontier Project, {Korea}},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {2197 - 2200}, 
  doi = {http://doi.org/10.1109/TASC.2003.813034}
}
Jung, H.-J., Nakamura, T., Muta, I. & Hoshino, T. Corrections to "Characteristics of Axial-Type HTS Motor under Different Temperature Conditions" (vol 13, pg 2201, 2003) [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(3), pp. 3821 - 3821 Article DOI
Abstract:
BibTeX:
@inbook{Jung:j2003,
  author = {Jung, Hun-June and Nakamura, Taketsune and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Corrections to "Characteristics of Axial-Type {HTS} Motor under Different Temperature Conditions" (vol 13, pg 2201, 2003)},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {September},
  volume = 13, 
  number=3,  
  pages = {3821 - 3821}, 
  doi = {http://doi.org/10.1109/TASC.2003.818522}
}
Jung, H.-J., Nakamura, T., Muta, I. & Hoshino, T. Characteristics of Axial-Type HTS Motor under Different Temperature Conditions [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 2201 - 2205 Article DOI
Abstract: We tested an axial-type Bi-2223 bulk motor under different magnetic field and temperature conditions. Distributed armature windings with a pole number of four were used in order to compensate for the harmonic components in the air-gap magnetic flux density. The temperature was varied by evacuating the metal cryostat with a rotary vacuum pump. The fabricated motor demonstrated hysteresis characteristics when the temperature of the system was decreased and the magnetomotive force was adjusted to appropriate values. Then, synchronous speed at no-load condition was fulfilled. On the other hand, slip of rotational speed as well as inductive torque was induced when temperature and magnetic conditions were not satisfied. These results can be explained based on the pinning properties and AC loss inside the bulk rotor.
BibTeX:
@inbook{Jung:j2003a,
  author = {Jung, Hun-June and Nakamura, Taketsune and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Characteristics of Axial-Type {HTS} Motor under Different Temperature Conditions},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {2201 - 2205}, 
  doi = {http://doi.org/10.1109/TASC.2003.813036}
}
Muta, I., Doshita, T., Nakamura, T., Egi, T. & Hoshino, T. Influences of Superconducting Fault Current Limiter (SFCL) on Superconducting Generator in One-Machine Double-Line System [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 2206 - 2209 Article DOI
Abstract: Analysis of superconducting generator in single machine double-line infinite-bus transmission system equipped with SFCL's has, been performed by use of EMTDC/PSCAD. When some faults occur in one transmission line, the SFCL in the fault line operates and then the peak fault current can be limited to expected value by use of a function of the SFCL. However, in some cases, the SFCL in the other sound line has been also proved to occasionally operate due to the interaction through each transmission line. Problems, due to an installation of the SFCL's in such a model system and the influences on the superconducting generator have been pointed out by simulation analysis.
BibTeX:
@inbook{Muta:j2003,
  author = {Muta, Itsuya and Doshita, Takeyuki and Nakamura, Taketsune and Egi, Toshiaki and Hoshino, Tsutomu},
  title = {Influences of Superconducting Fault Current Limiter ({SFCL}) on Superconducting Generator in One-Machine Double-Line System},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {2206 - 2209}, 
  doi = {http://doi.org/10.1109/TASC.2003.813037}
}
Muta, I., Nakamura, T., Jung, H.-J., Tanaka, N. & Hoshino, T. Starting and Steady State Characteristics of Axial-Type High Tc Superconducting Bulk Motor [BibTeX] [PDF] 2003 Proc. 2003 ICEMS (ICEMS2003), Vol. 1(OS-2-5), pp. 238 - 241 Inproceedings DOI URL
Abstract:
BibTeX:
@inbook{Muta:p2003,
  author = {Muta, Itsuya and Nakamura, Taketsune and Jung, Hun-June and Tanaka, Nobuyuki and Hoshino, Tsutomu},
  title = {Starting and Steady State Characteristics of Axial-Type High {Tc} Superconducting Bulk Motor},


  year = {2003},
  month = {November~9-11},
  volume = 1, 
  number=OS-2-5,  
  pages = {238 -- 241}, 
  url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1273856},
  doi = {http://doi.org/10.1109/ICEMS.2003.1273856}
}
Muta, I., Jung, H.-J., Nakamura, T., Morita, G. & Hoshino, T. Inverter-Fed Axial-Type High Tc Superconducting Bulk Motor [BibTeX] [PDF] 2003 Electromotion (Book), Proceedings of the 5th International Symposium on Advanced Electromechanical Motion Systems (ELECTROMOTION 2003), Vol.1, Marrakesh, Morrocco (2003.11.26-28)ELECTROMOTION, Vol. 1(3), pp. 144 - 147 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p2003a,
  author = {Muta, Itsuya and Jung, Hun-June and Nakamura, Taketsune and Morita, Gaku and Hoshino, Tsutomu},
  title = {Inverter-Fed Axial-Type High {Tc} Superconducting Bulk Motor},
  journal = {Electromotion (Book), Proceedings of the 5th International Symposium on Advanced Electromechanical Motion Systems (ELECTROMOTION 2003), Vol.1, Marrakesh, Morrocco (2003.11.26-28)},
  publisher = {Mediamira Science Publisher},
  year = {2003},
  month = {JulySeptember},
  volume = 1, 
  number=3,  
  pages = {144 - 147}, 
}
Muta, I., Nakamura, T., Jung, H.-J. & Hoshino, T. Comparative Study of Axial-type Bi-2223 Bulk Motor with the Use of Different Stator Windings [Abstract] [BibTeX] [PDF] 2003 Energy Efficiency in Motor Driven Systems, pp. 170 - 176 Inbook DOI
Abstract: Using high temperature superconducting (HTS) bulk materials, some types of bulk motors have been proposed and developed [1–4]. We have been studying the characteristics of electric motors with the use of Bi-2223 bulk disk rotor [5–8]. In order to do some preliminary researches, the stator of the motor has been constructed to be two-pole and three-phase concentrated armature winding wound around salient magnetic poles. The synchronous speed of the rotating magnetic field is in principle 3600 rpm. The test results, however, showed that the motor rotated with large slip and the torque decreased with increasing speed. As one of the main reasons for the results, we suppose the effect of the space harmonics of the air-gap magnetic field distribution. It is well known that magnetic space harmonics have the detrimental effect to motor performances. Therefore, the investigation of this effect is essential in order to realize the high performance HTS motor.
BibTeX:
@inbook{Muta2003,
  author = {Muta, Itsuya and Nakamura, Taketsune and Jung, Hun-June and Hoshino, Tsutomu},
  title = {Comparative Study of Axial-type Bi-2223 Bulk Motor with the Use of Different Stator Windings},
  journal = {Energy Efficiency in Motor Driven Systems},
  publisher = {Springer Berlin Heidelberg},
  year = {2003},



  pages = {170 - 176}, 
  doi = {http://doi.org/10.1007/978-3-642-55475-9_25}
}
Nakamura, T., Jung, H.-J., Fukui, K., Muta, I. & Hoshino, T. Electromagnetic Characteristics of Bi-2223 Disk in a Rotating Magnetic Field [Abstract] [BibTeX] [PDF] 2003 Physica C, Vol. 392-396, pp. 664 - 668 Article DOI
Abstract: The electromagnetic characteristics of disk shaped Bi-2223 bulk used for the rotor of an axial-type motor were studied in a rotating magnetic field. The magnetization of the Bi-2223 disk was measured by means of the Hall sensor that was mounted on the disk. It was shown that the fabricated axial-type motor generates standstill torque in proportion to the area of magnetization loops at weak applied field. Therefore, it can be deduced that the generated torque originates from hysteresis property of the bulk at this field region. Furthermore, the characteristics of Bi-2223 disk were also measured by varying the temperature with rotary vacuum pump in order to examine the dependency of the pinning property upon the torque characteristics, and the results are to be presented. (C) 2003 Elsevier B.V. All rights reserved.
BibTeX:
@inbook{Nakamura:j2003,
  author = {Nakamura, Taketsune and Jung, Hun-June and Fukui, Kentaro and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Electromagnetic Characteristics of {Bi}-2223 Disk in a Rotating Magnetic Field},
  journal = {Physica C},

  year = {2003},
  month = {October},
  volume = 392-396, 

  pages = {664 - 668}, 
  doi = {http://doi.org/10.1016/S0921-4534(03)00987-0}
}
Nakamura, T., Fukui, K., Jung, H.-J., Muta, I. & Hoshino, T. Investigation of Magnetic Characteristics in HTS Bulk Materials for Motor Applications [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 2255 - 2258 Article DOI
Abstract: Magnetic characteristics of Bi-2223 bulk rotor that was used for the HTS motor was investigated at 77.3 K. Spatial distribution of the magnetic flux density in the air-gap of axial-type HTS motor was measured in a rotating magnetic field at 60 Hz frequency. Numerical simulation based on 3D finite element method was also performed. It was shown that the pinning property of the bulk rotor influences the harmonic components of the air-gap flux density as well as motor characteristics.
BibTeX:
@inbook{Nakamura:j2003a,
  author = {Nakamura, Taketsune and Fukui, Kentaro and Jung, Hun-June and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Investigation of Magnetic Characteristics in {HTS} Bulk Materials for Motor Applications},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {2255 - 2258}, 
  doi = {http://doi.org/10.1109/TASC.2003.813059}
}
Nakamura, T., Higashikawa, K., Muta, I., Fujio, A., Okude, K. & Hoshino, T. Improvement of Dissipative Property in HTS Coil Impregnated with Solid Nitrogen [Abstract] [BibTeX] [PDF] 2003 Physica C, Vol. 386, pp. 415 - 418 Article DOI
Abstract: Dissipative property of high-T-c superconducting (HTS) coil impregnated with solid nitrogen was investigated. Small HTS solenoid coil was fabricated with the use of Bi-2223/Ag multifilamentary tape. Nitrogen was solidified by conduction cooling with Gifford-Macmafon cryocooler at cooling rate of 1 mKs(-1). Voltage as well as temperature of the coil was measured by applying the thermal disturbance and bias current. It was shown that the dissipation was reduced drastically by impregnating with solid nitrogen. Furthermore, the properties were also improved by pressurization in the sample chamber. This pressure effect may be due to the suppression of sublimation at the interface between the solid nitrogen and the coil. (C) 2002 Elsevier Science B.V. All rights reserved.
BibTeX:
@inbook{Nakamura:j2003b,
  author = {Nakamura, Taketsune and Higashikawa, Kohei and Muta, Itsuya and Fujio, Akihisa and Okude, Ken'ichi and Hoshino, Tsutomu},
  title = {Improvement of Dissipative Property in {HTS} Coil Impregnated with Solid Nitrogen},
  journal = {Physica C},

  year = {2003},
  month = {April},
  volume = 386, 

  pages = {415 - 418}, 
  doi = {http://doi.org/10.1016/S0921-4534(02)02193-7}
}
Salim, K.M., Hoshino, T., Kawasaki, A., Muta, I. & Nakamura, T. Waveform Analysis of the Bridge Type SFCL During Load Changing and Fault Time [Abstract] [BibTeX] [PDF] 2003 IEEE T. Appl. Supercond., Vol. 13(2), pp. 1992 - 1995 Article DOI
Abstract: DC reactor type SFCL has drawn the interest of some researchers in developing such device and more research work is being carried out in order to make it practically feasible. We have pointed out one issue that is not properly examined yet on such a device during load changing time. As we know, it is very difficult to introduce DC bias voltage to the reactor coil of the bridge type SFCL, some researchers are developing such device without using DC bias current. In such a case, the voltage drop occurs at the load terminal during the load increasing time caused by the DC reactor's inductance. By using the Electro-Magnetic Transients in DC systems Which is the simulator of electric networks (EMTDC) software we carried out analysis of first few half cycles of the voltage and current waveforms after the load is increased. We also performed the same analysis for fault conditions. The peak value of the waveforms is considered in calculating the voltage drop at load terminal during the load changing time. The analysis can be used in selecting an appropriate inductance value for designing such SFCL.
BibTeX:
@inbook{Salim:j2003,
  author = {Salim, Khosru Mohammad and Hoshino, Tsutomu and Kawasaki, Akio and Muta, Itsuya and Nakamura, Taketsune},
  title = {Waveform Analysis of the Bridge Type {SFCL} During Load Changing and Fault Time},
  journal = {IEEE T. Appl. Supercond.},

  year = {2003},
  month = {June},
  volume = 13, 
  number=2,  
  pages = {1992 - 1995}, 
  doi = {http://doi.org/10.1109/TASC.2003.812960}
}
Yamamoto, K., Osamura, K., Balamurugan, S., Nakamura, T., Hoshino, T. & Muta, I. Mechanical and Superconducting Properties of PIT-Processed MgB$_2$ Wire After Heat Treatment [Abstract] [BibTeX] [PDF] 2003 Supercond. Sci. Technol., Vol. 16(9), pp. 1052 - 1058 Article DOI
Abstract: The mechanical and superconducting properties of MgB$_2$ wires heat treated at various conditions have been investigated. Superconducting MgB2 wires, fabricated by the powder-in-tube (PIT) method, show a transition temperature T-c at 32.4 K for the as-rolled wire as shown by dc-resistivity measurement. It is found that the T-c is improved (37.3-38.4 K) by subsequent Ar annealing treatment under various sintering temperatures and times. Remarkably, the annealed samples show significant improvement in the overall quality of the samples. On annealing at 1323 K for 0.6 ks, we obtained the best quality sample with a J(c) of 470 A mm(-2) at 2.0 T. In order to find out the irreversible field (B-irr), the technique of the Kramer plot was applied. The B-irr obtained was 7.6 and 9.6 T, for the as-rolled as well as the annealed samples at 1073 K for 3.6 ks, respectively. The mechanical properties were measured under tensile load. The yield stress was 450 MPa for the as-rolled sample and decreased by annealing at 1323 K for 0.6 ks to 110 MPa. After the wires were heat treated at temperatures between 1073 and 1323 K and tensile-stressed up to their yield stress at room temperature. The critical current measurements were carried on such samples at 4.2 K under applied magnetic fields of 2 and 5 T. The stress level for the 95\% tolerance of critical current was determined to 97 MPa.
BibTeX:
@inbook{Yamamoto:j2003,
  author = {Yamamoto, Kenji and Osamura, Kozo and Balamurugan, Sarkarainadar and Nakamura, Taketsune and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Mechanical and Superconducting Properties of {PIT}-Processed {MgB}$_{2}$ Wire After Heat Treatment},
  journal = {Supercond. Sci. Technol.},

  year = {2003},
  month = {September},
  volume = 16, 
  number=9,  
  pages = {1052 - 1058}, 
  doi = {http://doi.org/10.1088/0953-2048/16/9/315}
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. Optimal Design of a Superconducting Generator Using Genetic Algorithm [BibTeX] [PDF] 2002 Conference Record of the 15th ICEM (ICEM2002)Conference Record of the 15th ICEM (ICEM2002), pp. 198 - 201 Inproceedings
Abstract:
BibTeX:
@inbook{Han:p2002,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Optimal Design of a Superconducting Generator Using Genetic Algorithm},
  journal = {Conference Record of the 15th ICEM (ICEM2002)},

  year = {2002},
  month = {August26},


  pages = {198 - 201}, 
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. Multi-Objective Optimal Design of Superconducting Generator Using Genetic Algorithm [BibTeX] [PDF] 2002 Proc. 4th Asia-Pacific Conference on Simulated Evolution and Learning, pp. 60 - 64 Inproceedings URL
Abstract:
BibTeX:
@inbook{Han:p2002a,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Multi-Objective Optimal Design of Superconducting Generator Using Genetic Algorithm},


  year = {2002},
  month = {November},


  pages = {60 - 64}, 
  url = {http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.67.813&rep=rep1&type=pdf},
}
Jang, H.-M., Muta, I., Hoshino, T., Nakamura, T., Kim, S.-W., Sohn, M.-H., Kwon, Y.-K. & Ryu, K.-S. Conceptual Design of 100 HP Synchronous Motor with HTS Field Winding [BibTeX] [PDF] 2002 Proc.ICEE, Vol. 3(sup-6), pp. 1618 - 1623 Inproceedings
Abstract:
BibTeX:
@inbook{Jang:p2002,
  author = {Jang, Hyung-Man and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune and Kim, Seog-Whan and Sohn, Myung-Hwan and Kwon, Young-Kil and Ryu, Kang-Sik},
  title = {Conceptual Design of 100 {HP} Synchronous Motor with {HTS} Field Winding},


  year = {2002},
  month = {July},
  volume = 3, 
  number=sup-6,  
  pages = {1618 -- 1623}, 
}
Mao, X., Chen, B., Zhu, C. & Hoshino, T. Study on Transforming from Painting to Music [Abstract] [BibTeX] [PDF] 2002 Video/Image Processing and Multimedia Communications 4th EURASIP-IEEE Region 8 International Symposium on VIPromComInternational Symposium on VIPromCom Video/Image Processing and Multimedia Communications, pp. 117 - 120 Inproceedings DOI
Abstract: This paper aims at probing into the mapping relationship and rules between painting and music. After the examination of corresponding relation between image and music, relevant arithmetic is put forward in accordance with certain principles in scientific and art, in which the original information in the image is converted into musical information, thus enabling people to obtain visual impression from audio objects and achieving the integration of science and art.
BibTeX:
@inbook{Mao:p2002,
  author = {Mao, Xia and Chen, Bin and Zhu, Chen and Hoshino, Tsutomu},
  title = {Study on Transforming from Painting to Music},
  journal = {Video/Image Processing and Multimedia Communications 4th EURASIP-IEEE Region 8 International Symposium on VIPromCom},
  publisher = {Institute of Electrical {\&} Electronics Engineers ({IEEE})},
  year = {2002},
  month = {6~16-19},


  pages = {117 - 120}, 
  doi = {http://doi.org/10.1109/viprom.2002.1026639}
}
Muta, I., Jung, H.-J., Nakamura, T. & Hoshino, T. Performance of Axial-Type Motor with Bi-2223 HTS Bulk Rotor [Abstract] [BibTeX] [PDF] 2002 Physica C, Vol. 372, pp. 1531 - 1534 Article DOI
Abstract: We fabricated and tested an axial-type motor with a Bi-2223 bulk to investigate its applicability. The motor was immersed in liquid nitrogen with zero-field cooling method. Load and locked rotor tests were carried out in a rotating magnetic field at 60 Hz frequency. Load tests showed that the fabricated motor does not reach synchronous speed, and torque declines with increasing rotational speed. These properties are similar to those of induction motor with high rotor resistance. On the other hand, locked rotor test indicates that the torque vs. magnetic field characteristics is qualitatively described by the area of hysteresis loop which is measured on a bulk surface with a hall sensor. That is, the fabricated motor shows both characteristics of conventional induction and hysteresis motors.
BibTeX:
@inbook{Muta:j2002,
  author = {Muta, Itsuya and Jung, Hun-June and Nakamura, Taketsune and Hoshino, Tsutomu},
  title = {Performance of Axial-Type Motor with {Bi}-2223 {HTS} Bulk Rotor},
  journal = {Physica C},

  year = {2002},
  month = {August},
  volume = 372, 

  pages = {1531 - 1534}, 
  doi = {http://doi.org/10.1016/S0921-4534(02)01078-X}
}
Muta, I., Jung, H.-J., Nakamura, T. & Hoshino, T. Performance Evaluation of Axial-Type Superconducting BSCCO-2223 Motor [BibTeX] [PDF] 2002 Conference Record of the 15th ICEM (ICEM2002)Conference Record of the 15th ICEM (ICEM2002), pp. 190 - 195 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p2002,
  author = {Muta, Itsuya and Jung, Hun-June and Nakamura, Taketsune and Hoshino, Tsutomu},
  title = {Performance Evaluation of Axial-Type Superconducting {BSCCO}-2223 Motor},
  journal = {Conference Record of the 15th ICEM (ICEM2002)},

  year = {2002},
  month = {August26},


  pages = {190 - 195}, 
}
Muta, I., Nakamura, T., Jung, H.-J. & Hoshino, T. Comparative Study of Axial-type Bi-2223~Bulk Motor with the Use of Different Stator Windings [Abstract] [BibTeX] [PDF] 2002 Energy Efficiency in Motor Driven Systems, Proc. 3rd International Conference on Energy Efficiency in Motor Driven Systems (EEMODS2002)Energy Efficiency in Motor Driven Systems, pp. 170-176 Incollection DOI
Abstract: Using high temperature superconducting (HTS) bulk materials, some types of bulk motors have been proposed and developed [1–4]. We have been studying the characteristics of electric motors with the use of Bi-2223 bulk disk rotor [5–8]. In order to do some preliminary researches, the stator of the motor has been constructed to be two-pole and three-phase concentrated armature winding wound around salient magnetic poles. The synchronous speed of the rotating magnetic field is in principle 3600 rpm. The test results, however, showed that the motor rotated with large slip and the torque decreased with increasing speed. As one of the main reasons for the results, we suppose the effect of the space harmonics of the air-gap magnetic field distribution. It is well known that magnetic space harmonics have the detrimental effect to motor performances. Therefore, the investigation of this effect is essential in order to realize the high performance HTS motor.
BibTeX:
@inbook{Muta:p2002a,
  author = {Muta, Itsuya and Nakamura, Taketsune and Jung, Hun-June and Hoshino, Tsutomu},
  title = {Comparative Study of Axial-type Bi-2223~{B}ulk Motor with the Use of Different Stator Windings},
  journal = {Energy Efficiency in Motor Driven Systems, Proc. 3rd International Conference on Energy Efficiency in Motor Driven Systems (EEMODS2002)},
  publisher = {Springer Science $\mathplus$ Business Media},
  year = {2002},
  month = {September18-29},


  pages = {170--176}, 
  doi = {http://doi.org/10.1007/978-3-642-55475-9_25}
}
Nakamura, T., Muta, I., Okude, K., Fujio, A. & Hoshino, T. Solidification of Nitrogen Refrigerant and its Effect on Thermal Stability of HTSC Tape [Abstract] [BibTeX] [PDF] 2002 Physica C, Vol. 372, pp. 1434 - 1437 Article DOI
Abstract: We investigated the effect of solidified nitrogen refrigerant upon the thermal stability of HTSC tape. Solid nitrogen was produced by two methods, one by conduction cooling at a very slow cooling rate and another by evacuating the vapor. It was shown experimentally that the thermal stability of HTSC tape is improved drastically when it is impregnated with solid nitrogen produced by the conduction cooling. Furthermore, so-called dry-out phenomenon was dominated by the cumulative energy of the thermal disturbance by the heater. (C) 2002 Elsevier Science B.V. All rights reserved.
BibTeX:
@inbook{Nakamura:j2002,
  author = {Nakamura, Taketsune and Muta, Itsuya and Okude, Ken'ichi and Fujio, Akihisa and Hoshino, Tsutomu},
  title = {Solidification of Nitrogen Refrigerant and its Effect on Thermal Stability of {HTSC} Tape},
  journal = {Physica C},

  year = {2002},
  month = {August},
  volume = 372, 

  pages = {1434 - 1437}, 
  doi = {http://doi.org/10.1016/S0921-4534(02)01047-X}
}
Nakamura, T., Tsuchiya, S., Fujio, A., Hoshino, T., Muta, I. & Yamaguchi, M. Angular Dependence of $E-J$ Characteristics and Dissipative Properties in Bi-2223/Ag Tape [Abstract] [BibTeX] [PDF] 2002 Supercond. Sci. Technol., Vol. 15(2), pp. 230 - 235 Article DOI
Abstract: We study the angular dependence of E-J characteristics and dissipative properties due to thermal disturbance in the Bi-2223/Ag multifilamentary tape in the low-voltage region. In order to simulate the dissipative properties, we take into account the analytical expressions of the E-J characteristics as a function of temperature, external magnetic field and field direction, which agree well with the experimental data. It is shown that the simulation results of the dissipative properties agree with the experimental data semi-quantitatively. The relationship between the current sharing rate and its contribution to the temperature increase is also discussed, based on the simulation. These results are crucial for high-T-c superconducting power application systems with a persistent current mode where even low-power dissipation is detrimental to the performance.
BibTeX:
@inbook{Nakamura:j2002a,
  author = {Nakamura, Taketsune and Tsuchiya, Shingo and Fujio, Akihisa and Hoshino, Tsutomu and Muta, Itsuya and Yamaguchi, Mitsugu},
  title = {Angular Dependence of {$E-J$} Characteristics and Dissipative Properties in {Bi}-2223/{Ag} Tape},
  journal = {Supercond. Sci. Technol.},

  year = {2002},

  volume = 15, 
  number=2,  
  pages = {230 - 235}, 
  doi = {http://doi.org/10.1088/0953-2048/15/2/309}
}
中村 武恒, 奥出 健一, 藤尾 彰尚, 牟田 一彌 & 星野 勉 3重点近傍における固体窒素含浸Bi-2223/Agテープの熱伝達特性 [Abstract] [BibTeX] [PDF] 2002 低温工学, Vol. 37(9), pp. 465 - 471 Article DOI
Abstract: Heat transfer property of Bi-2223/Ag multifilamentary tape impregnated with solid nitrogen was investigated by measuring the voltage and temperature traces on the tape. Solid nitrogen was produced by two different methods: i.e., one by conduction cooling with GM cryocooler, and another by evacuation with rotary vacuum pump. The heat transfer coefficient between the tape and the solid nitrogen was estimated based upon the numerical simulation. It was shown that the equivalent heat transfer coefficient of the tape impregnated with solid nitrogen made by conduction cooling at a very slow cooling rate was more than six times larger than that made by evacuation.
BibTeX:
@inbook{Nakamura:j2002b,
  author = {中村 武恒 and 奥出 健一 and 藤尾 彰尚 and 牟田 一彌 and 星野 勉},
  title = {3重点近傍における固体窒素含浸{Bi-2223/Ag}テープの熱伝達特性},
  journal = {低温工学},

  year = {2002},
  month = {September 25},
  volume = 37, 
  number=9,  
  pages = {465 - 471}, 
  doi = {http://doi.org/10.2221/jcsj.37.465}
}
中村 武恒, 牟田 一彌, 鄭 憲俊 & 星野 勉 Bi-2223バルク回転子を適用したアキシャル型高温超電導モータの電磁的基礎特性 [Abstract] [BibTeX] [PDF] 2002 低温工学, Vol. 37(11), pp. 726 - 733 Article DOI
Abstract: We have tested an axial-type motor that was fabricated using a disk-shaped Bi-2223 bulk rotor. Two-pole and three-phase copper coils were used for concentrated armature windings. Lock and load tests were performed as a function of temperature at a frequency of 60Hz. In order to examine the test results, the spatial harmonics of the air-gap magnetic flux density were measured at room temperature and 77.3K, and then analyzed by Fast Fourier Transformation. Hysteresis curves of the Bi-2223 bulk rotor were also measured in a rotating magnetic field at 77.3K. It was shown that the air-gap magnetic flux density includes large components of 5th and 7th harmonics due to the salient and concentrated armature windings, and these harmonics may be one of the main reasons for asynchronous torque as well as large slip operation. On the other hand, these harmonics are suppressed when the armature current is increased due to the heating with AC loss. Furthermore, it can be deduced from a comparison between the stational torque and the area of hysteresis loops that torque generation varies from hysteresis-dominant to induction-dominant mechanisms at the point the gradient of torque vs. armature current curve changes. These results are reasonably consistent with the temperature dependence of motor characteristics.
BibTeX:
@inbook{Nakamura:j2002c,
  author = {中村 武恒 and 牟田 一彌 and 鄭 憲俊 and 星野 勉},
  title = {Bi-2223バルク回転子を適用したアキシャル型高温超電導モータの電磁的基礎特性},
  journal = {低温工学},

  year = {2002},
  month = {November},
  volume = 37, 
  number=11,  
  pages = {726 - 733}, 
  doi = {http://doi.org/10.2221/jcsj.37.726}
}
Salim, K.M., Hoshino, T., Nishikawa, M., Muta, I. & Nakamura, T. Preliminary Experiments on Saturated DC Reactor Type Fault Current Limiter [Abstract] [BibTeX] [PDF] 2002 IEEE T. Appl. Supercond., Vol. 12(1), pp. 872 - 875 Article DOI
Abstract: Preliminary experiments have been performed on our proposed saturated DC reactor type superconducting fault current limiter (SFCL). The proposed SFCL is similar to a DC reactor type but an additional control winding is used. The DC bias current in the control winding saturates the core. The B-H curve of a magnetic circuit shows that low inductance value can be achieved in saturated region and high value in unsaturated region. The inductance of the saturated reactor depends on type of magnetic material, core size, number of turns and biasing conditions. The advantage of this type of SFCL over the existing DC reactor type is that, it shows low inductance value at normal operation and high value during fault time. On the other hand, the present DC reactor type SFCL shows a fixed value of inductance both in normal and fault time. In our experiment, we observed the inductance behavior of the saturated reactor by changing the control current. In order to make the work simple and convenient we have chosen a ferrite core. The experimental results are presented in this paper.
BibTeX:
@inbook{Salim:j2002,
  author = {Salim, Khosru Mohammad and Hoshino, Tsutomu and Nishikawa, Massanori and Muta, Itsuya and Nakamura, Taketsune},
  title = {Preliminary Experiments on Saturated {DC} Reactor Type Fault Current Limiter},
  journal = {IEEE T. Appl. Supercond.},

  year = {2002},
  month = {March},
  volume = 12, 
  number=1,  
  pages = {872 - 875}, 
  doi = {http://doi.org/10.1109/TASC.2002.1018539}
}
Han, S.-I., Muta, I., Hoshino, T. & Nakamura, T. GA Design for Efficiency Optimization of a Superconducting Generator [Abstract] [BibTeX] [PDF] 2001 ICEMStextquotesingle2001.Proc. 5th ICEMS (IEEE Cat. No.01EX501), Vol. 1, pp. 152 - 155 Inproceedings DOI
Abstract: This paper deals with a design method for the efficiency optimization of 223 MVA class superconducting generator. In consideration of the electrical characteristics based on electromagnetic analysis, GA (genetic algorithm), which has been successfully applied to various design problems in electric machines and devices, is used as an approach method of the optimized design with some variables and constraints. The results designed by this method are found to be reasonable and effective as compared with those obtained by the methods of trial and error until now
BibTeX:
@inbook{Han:p2001,
  author = {Han, Sang-Il and Muta, Itsuya and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {{GA} Design for Efficiency Optimization of a Superconducting Generator},

  publisher = {Institute of Electrical {\&} Electronics Engineers ({IEEE})},
  year = {2001},
  month = {August18-20},
  volume = 1, 

  pages = {152 - 155}, 
  doi = {http://doi.org/10.1109/ICEMS.2001.970631}
}
Hoshino, T., Salim, K.M., Nishikawa, M., Muta, I. & Nakamura, T. Proposal of Saturated DC Reactor Type Superconducting Fault Current Limiter (SFCL) [Abstract] [BibTeX] [PDF] 2001 Cryogenics, Vol. 41(7), pp. 469 - 474 Article DOI
Abstract: A new superconducting fault current limiter (SFCL) using DC biased saturated core have been proposed in this paper. All existing saturated core SFCL are AC type. The proposed SFCL is a DC reactor type where all the windings carry DC current. The B-H curve of a magnetic circuit shows that less inductance value can be achieved in saturated region and very high value in unsaturated region. The reactance window between the saturated and unsaturated region depends on magnetic material, core size and its biasing conditions. The proposed type of SFCL can be designed efficiently taking the full advantage of the reactance window in current limiting mode. The advantage of this type of SFCL over the existing DC reactor type is that, it shows very low value of inductance at normal operation and very high value during fault time. On the other hand, the existing DC reactor (bridge) type SFCL shows a fixed value of inductance both in normal and fault time. Some simulation results are presented here to show the performance of the proposed SFCL.
BibTeX:
@inbook{Hoshino:j2001,
  author = {Hoshino, Tsutomu and Salim, Khosru Mohammad and Nishikawa, Massanori and Muta, Itsuya and Nakamura, Taketsune},
  title = {Proposal of Saturated {DC} Reactor Type Superconducting Fault Current Limiter {(SFCL)}},
  journal = {Cryogenics},

  year = {2001},
  month = {July},
  volume = 41, 
  number=7,  
  pages = {469 - 474}, 
  doi = {http://doi.org/10.1016/S0011-2275(01)00096-0}
}
Hoshino, T., Nishikawa, M., Salim, K.M., Nakamura, T. & Muta, I. Preliminary Studies on Characteristics of Series-Connected Resistive Type Superconducting Fault Current Limiter for System Design [Abstract] [BibTeX] [PDF] 2001 Physica C, Vol. 354(1-4), pp. 120 - 124 Article DOI
Abstract: One element of superconducting fault current limiter (SFCL) has relative low rated voltage and current compared with power grid voltage and current. It means up to hundreds superconducting limiter elements have to be connected in series. To simplify the analysis, we assumed that the superconducting limiter element is expressed with parallel connection of switch and resistance - this condition means severe situation to all elements operation. The current and voltage waveforms are described and the results reveal relationships between SFCL transition current level, the target value to reduce, the normal resistance of the elements, maximum terminal voltage, and the number of elements in series. These relations yield guideline on the system design of series-connected SFCL.
BibTeX:
@inbook{Hoshino:j2001a,
  author = {Hoshino, Tsutomu and Nishikawa, Massanori and Salim, Khosru Mohammad and Nakamura, Taketsune and Muta, Itsuya},
  title = {Preliminary Studies on Characteristics of Series-Connected Resistive Type Superconducting Fault Current Limiter for System Design},
  journal = {Physica C},

  year = {2001},
  month = {May},
  volume = 354, 
  number=1-4,  
  pages = {120 - 124}, 
  doi = {http://doi.org/10.1016/S0921-4534(01)00062-4}
}
Hoshino, T., Salim, K.M., Nishikawa, M., Muta, I. & Nakamura, T. DC Reactor Effect on Bridge Type Superconducting Fault Current Limiter During Load Increasing [Abstract] [BibTeX] [PDF] 2001 IEEE T. Appl. Supercond., Vol. 11(1), pp. 1944 - 1947 Article DOI
Abstract: In high power application, the fault current limiter has been discussed for many years because of some limitations of conventional circuit breaker. Many types of fault current limiter have already been introduced in papers. In this work, a simple bridge type fault current limiter has been designed and constructed. The performances of the limiter have been tested successfully. In bridge type current limiter, DC reactor appears in the line when connected load is increasing. This causes voltage drop across the load terminal during load changing. The DC reactor effect of the current limiter has been studied. Some experimental results regarding reactor effect of the limiter have been considered and were compared with the results obtained from computer simulation.
BibTeX:
@inbook{Hoshino:j2001b,
  author = {Hoshino, Tsutomu and Salim, Khosru Mohammad and Nishikawa, Massanori and Muta, Itsuya and Nakamura, Taketsune},
  title = {{DC} Reactor Effect on Bridge Type Superconducting Fault Current Limiter During Load Increasing},
  journal = {IEEE T. Appl. Supercond.},

  year = {2001},
  month = {March},
  volume = 11, 
  number=1,  
  pages = {1944 - 1947}, 
  doi = {http://doi.org/10.1109/77.920232}
}
Muta, I., Nakamura, T., Hirata, T., Hoshino, T. & Konishi, T. Preliminary Study on Axial-Type BSCCO Superconducting Motor [Abstract] [BibTeX] [PDF] 2001 Physica C, Vol. 354(1-4), pp. 100 - 104 Article DOI
Abstract: A small axial-type BSCCO high-T-c Superconducting motor cooled with liquid nitrogen has been fabricated and tested in terms of speed, torque and speed-torque characteristic curves. BSCCO bulky disk is used to be 120 mm in diameter and 8 mm thick, and two-pole concentrated armature winding is fed with the PWM inverter. The BSCCO machine could substantially operate as hysteresis motor. In the experimental motor, M-H characteristic curves at different local points of the BSCCO disk were not same, air-gap magnetic flux density was not completely sinusoidal, and viscosity losses existed due to liquid nitrogen, so that the motor could not rotate at synchronous speed. Performances have been evaluated and an equivalent circuit of the BSCCO-2223 bulk motor has been estimated from test results. (C) 2001 Elsevier Science B.V. All rights reserved.
BibTeX:
@inbook{Muta:j2001,
  author = {Muta, Itsuya and Nakamura, Taketsune and Hirata, Tomohiro and Hoshino, Tsutomu and Konishi, Takeshi},
  title = {Preliminary Study on Axial-Type {BSCCO} Superconducting Motor},
  journal = {Physica C},

  year = {2001},
  month = {May},
  volume = 354, 
  number=1-4,  
  pages = {100 - 104}, 
  doi = {http://doi.org/10.1016/S0921-4534(01)00059-4}
}
Muta, I., Jung, H.-J., Hirata, T., Nakamura, T., Hoshino, T. & Konishi, T. Fundamental Experiments of Axial-Type BSCCO-Bulk Superconducting Motor Model [Abstract] [BibTeX] [PDF] 2001 IEEE T. Appl. Supercond., Vol. 11(1), pp. 1964 - 1967 Article DOI
Abstract: An axial type HTS hysteresis motor has the same structure as a conventional axial fur type permanent magnet synchronous motor. The permanent magnet. rotor of a conventional permanent magnet synchronous motor is replaced by a rotor made from HTS materials with the objective of increasing power densities and reducing losses. The behavior of a BSCCO bulk rotor has been tested in rotating magnetic fields produced by two poles and three phase motor coils fed by a PWM inverter at 77 K. To characterize the torque output capability of the HTS hysteresis motor, speed versus torque and current versus torque are tested. Experimental results for the HTS hysteresis motor are presented.
BibTeX:
@inbook{Muta:j2001a,
  author = {Muta, Itsuya and Jung, Hun-June and Hirata, Tomohiro and Nakamura, Taketsune and Hoshino, Tsutomu and Konishi, Takeshi},
  title = {Fundamental Experiments of Axial-Type {BSCCO}-Bulk Superconducting Motor Model},
  journal = {IEEE T. Appl. Supercond.},

  year = {2001},
  month = {March},
  volume = 11, 
  number=1,  
  pages = {1964 - 1967}, 
  doi = {http://doi.org/10.1109/77.920237}
}
Muta, I., Yoshimoto, K., Hoshino, T. & Nakamura, T. Dynamic Stability of a Superconducting Generator in the Electric Power System [Abstract] [BibTeX] [PDF] 2001 Proc. 5th ICEMSICEMStextquotesingle2001. Proceedings of the Fifth International Conference on Electrical Machines and Systems (IEEE Cat. No.01EX501), Vol. 1, pp. 668 - 671 Inproceedings DOI
Abstract: This paper presents the dynamic stability of a superconducting generator of 200 MW class connected to an infinite busbar through a power transmission line. Details regarding damping ratio, nondamped natural frequency and output power limit of the machine have been investigated. Furthermore, a superconducting generator system with series-connected capacitor in the power transmission-fine has been studied from the viewpoint of stability improvement. This paper also examines dynamic performances dependence upon control systems such as AVR and GOV (Governor)
BibTeX:
@inbook{Muta:p2001,
  author = {Muta, Itsuya and Yoshimoto, Kunihiro and Hoshino, Tsutomu and Nakamura, Taketsune},
  title = {Dynamic Stability of a Superconducting Generator in the Electric Power System},
  journal = {Proc. 5th ICEMS},
  publisher = {Institute of Electrical {\&} Electronics Engineers ({IEEE})},
  year = {2001},
  month = {August18-20},
  volume = 1, 

  pages = {668 - 671}, 
  doi = {http://doi.org/10.1109/ICEMS.2001.970763}
}
Nakamura, T., Tsuchiya, S., Fujio, A., Hoshino, T. & Muta, I. Influence of Magnetic Field and Magnetic Anisotropy on the Quench Characteristics of Bi-2223/Ag Multifilamentary Tapes [Abstract] [BibTeX] [PDF] 2001 IEEE T. Appl. Supercond., Vol. 11(1), pp. 3341 - 3344 Article DOI
Abstract: We examined the normal propagation characteristics of Bi-2223/Ag multifilamentary tapes as a function of magnetic field direction. Anisotropic current transport characteristics were estimated by taking into account the effect of the misorientation of the grains. Anisotropic normal zone propagation properties were examined based on the numerical simulation, and showed that the thermal properties were influenced by the anisotropic current transport characteristics.
BibTeX:
@inbook{Nakamura:j2001,
  author = {Nakamura, Taketsune and Tsuchiya, Shingo and Fujio, Akihisa and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Influence of Magnetic Field and Magnetic Anisotropy on the Quench Characteristics of {Bi}-2223/{Ag} Multifilamentary Tapes},
  journal = {IEEE T. Appl. Supercond.},

  year = {2001},
  month = {March},
  volume = 11, 
  number=1,  
  pages = {3341 - 3344}, 
  doi = {http://doi.org/10.1109/77.919778}
}
손 명한, 권 영길, 백 승규, 박 도영, 이 언용, 조 영식, 류 강식, 牟田 一彌 & 星野 勉 30[kVA] 초전도발전가 제작 및 특성 [Abstract] [BibTeX] [PDF] 2001 한국초전도・저온공학회논문지, Vol. 3(2), pp. 32 - 38 Article URL
Abstract: A 30[kVA] superconducting generator (SCG) is built and tested at Korea Electrotechnology Research Institute (KERI) in Korea. This superconducting generator has an air-gap winding instead of the typical steel teeth structure. The rotor has 4 field coils of race-track type with NbTi superconducting wired. The rotor is composed of two dampers and a liquid helium composed of two dampers and a liquid helium container in which the field poles reside. The space between the outermost damper and the container is vacuum insulated. A ferrofluid seal is used between the stationary part connected to the couping and the rotor. A helium transfer coupling(HTC) has 3 passages of the recovered heilum gas and a gas flow control system. The open circuit test and sustained short circuit test are preformed to obtain the open circuit characteristics (OCC) and short circuit characteristics (SCC) Also. the test results usder the light load (up to 3.6[kW]) are given. The structure, manufacturing and basis test of the 30[kVA]SCG are discussed.
BibTeX:
@inbook{Sohn:j2001,
  author = {손 명한 and 권 영길 and 백 승규 and 박 도영 and 이 언용 and 조 영식 and 류 강식 and 牟田 一彌 and 星野 勉},
  title = {30[{kVA}] 초전도발전가 제작 및 특성},
  journal = {한국초전도・저온공학회논문지},

  year = {2001},
  month = {November},
  volume = 3, 
  number=2,  
  pages = {32 - 38}, 
  url = {http://ocean.kisti.re.kr/IS_mvpopo213L.do?ResultTotalCNT=14&pageNo=1&pageSize=10&method=view&poid=kiasc&kojic=CJJOCB&sVnc=v3n2&id=6&setId=18860&iTableId=4&iDocId=405319&sFree=},
}
Tsukiji, H., Hoshino, T. & Muta, I. Output Power Limit of 200 MW Class Brushless Superconducting Generator Excited with Magnetic Flux-Pump [Abstract] [BibTeX] [PDF] 2001 IEEE T. Appl. Supercond., Vol. 11(1), pp. 2335 - 2338 Article DOI
Abstract: A study on excitation system would he important to enhance potentials of superconducting AC generators. We have fabricated a 20 kW class fully superconducting machine with the brushless excitation system which consists of magnetic flux-pump. By many tests of power generation using this machine, we have investigated theoretically and experimentally the feasibility of brushless superconducting generator and magnetic flux-pump. Based on these results, this paper proposes conceptual design and electric characteristics of practical scale flux pump for exciter system of 200 MW class superconducting generator (Super-GM). Furthermore, the paper presents a comparison BE output power limits for such as different excitation methods; a persistent field current mode and a conventionally adjusting held current mode.
BibTeX:
@inbook{Tsukiji:j2001,
  author = {Tsukiji, Hiroshi and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Output Power Limit of 200 {MW} Class Brushless Superconducting Generator Excited with Magnetic Flux-Pump},
  journal = {IEEE T. Appl. Supercond.},

  year = {2001},
  month = {March},
  volume = 11, 
  number=1,  
  pages = {2335 - 2338}, 
  doi = {http://doi.org/10.1109/77.920329}
}
Baik, S.-K., Sohn, M.-H., Park, D.-Y., Ahn, J.B., Kwon, Y.-K., Ryu, K.-S., Jo, Y.-S., Muta, I. & Hoshino, T. A 30kVA Superconducting Generator Development and Basic Tests [Abstract] [BibTeX] [PDF] 2000 IEEE T. Appl. Supercond., Vol. 10(1), pp. 947 - 950 Article DOI
Abstract: A 30kVA superconducting generator (S.G.) has been designed, developed and successfully tested in Korea Electrotechnology Research Institute(KERI) before the end of last year. The design is based on 2-dimensional electromagnetic held analysis of cylindrical coordinate. The field winding of rotor has been wound with superconducting wire of NbTi alloy and tested after assembled with other rotor components. The stator has air-gap type armature windings, which produce higher terminal voltage, and more sinusoidal voltage waveform than conventional iron cored machines. Steady- state open & short-circuit test and lamp load test have been conducted also, The results of tests are given in this paper and compared with design quantities. Moreover the cooling scheme and characteristics of test system is included.
BibTeX:
@inbook{Baik:j2000,
  author = {Baik, Seung-Kyu and Sohn, Myung-Hwan and Park, Doh-Young and Ahn, J. B. and Kwon, Young-Kil and Ryu, Kang-Sik and Jo, Young-Sik and Muta, Itsuya and Hoshino, Tsutomu},
  title = {A {30kVA} Superconducting Generator Development and Basic Tests},
  journal = {IEEE T. Appl. Supercond.},
  publisher = {IEEE Inc.},
  year = {2000},
  month = {March},
  volume = 10, 
  number=1,  
  pages = {947 - 950}, 
  doi = {http://doi.org/10.1109/77.828388}
}
Hoshino, T., Yamaji, N., Muta, I., Nakamura, T., Higuchi, N., Natori, N., Fuchino, S. & Arai, K. Measured-Loss Analysis of Superconducting Power Transmission Cable [Abstract] [BibTeX] [PDF] 2000 IEEE T. Appl. Supercond., Vol. 10(1), pp. 1223 - 1226 Article DOI
Abstract: In the former work [6], the eddy current loss in the former due to pitch difference between current conductor and shield conductor was studied. The calculated value was negligible small which does not explain the measured value. The eddy current loss due to radial component of the magnetic field become comparable with the measured value. In this paper, the reason of the increased loss is revealed. The disturbance of the conductor pitch yields different strength of the axial magnetic field. The difference of the axial flux toward the radial direction as the radial component of the flux. The flux causes eddy current loss in the copper for stabilizer. It is well match with the measured value.
BibTeX:
@inbook{Hoshino:j2000,
  author = {Hoshino, Tsutomu and Yamaji, Norifumi and Muta, Itsuya and Nakamura, Taketsune and Higuchi, Noboru and Natori, Naotake and Fuchino, Shuichiro and Arai, Kazuaki},
  title = {Measured-Loss Analysis of Superconducting Power Transmission Cable},
  journal = {IEEE T. Appl. Supercond.},

  year = {2000},
  month = {March},
  volume = 10, 
  number=1,  
  pages = {1223 - 1226}, 
  doi = {http://doi.org/10.1109/77.828455}
}
Hoshino, T., Muta, I. & Nakamura, T. Applied High-Tc Superconducting Electrical Machines [Abstract] [BibTeX] [PDF] 2000 Proc. 2000 KIASC Conference, pp. 73 - 76 Inproceedings URL
Abstract: Superconductivity is key technology for 21st century. To suppress emission of green house effect gas, applied superconductivity is important. In this paper, the current status of superconducting power machines such as generatorand motor are described. Most of all studies are the step of demonstration of idea and possibility. There are large gap between physical idea and actual apparatus. Further collaboration between scientists and engineers has been required.
BibTeX:
@inbook{Hoshino:p2000,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Nakamura, Taketsune},
  title = {Applied High-{Tc} Superconducting Electrical Machines},


  year = {2000},
  month = {February},


  pages = {73 - 76}, 
  url = {http://ocean.kisti.re.kr/IS_mvpopo001P.do?method=multMain&poid=kiasc},
}
Hoshino, T., Ashida, N., Muta, I., Nakamura, T., Tsukiji, H., Noguchi, Y. & Suzuki, M. Turn-off Energy Reductions of Superconducting Power Electronics Devices (S-PED) [BibTeX] [PDF] 2000 Proc. 2000 IPEC, Vol. 3, pp. 1416 - 1421 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p2000a,
  author = {Hoshino, Tsutomu and Ashida, Nobuyuki and Muta, Itsuya and Nakamura, Taketsune and Tsukiji, Hiroshi and Noguchi, Yoshio and Suzuki, Morio},
  title = {Turn-off Energy Reductions of Superconducting Power Electronics Devices ({S-PED})},


  year = {2000},
  month = {April},
  volume = 3, 

  pages = {1416 - 1421}, 
}
Nakamura, T., Yamamoto, T., Tsuchiya, S., Fujio, A., Hoshino, T., Muta, I., Oh, S.-S. & Ha, H.-S. Anisotropy of Critical Current and Glass-Liquid Transition Flux Density in Bi-2223/Ag Tape [Abstract] [BibTeX] [PDF] 2000 Supercond. Sci. Technol., Vol. 13(11), pp. 1521 - 1525 Article DOI
Abstract: We present the anisotropy of current transport characteristics in Bi-2223/Ag multifilamentary tapes as a function of temperature and external magnetic field. Angular dependence of the critical current and the glass-liquid transition magnetic flux density are well described by the model, taking into account the misorientation of grains with constant effective anisotropy factor, gamma. Furthermore, gamma increases apparently as temperature and/or critical current increases due to the weak-link properties.
BibTeX:
@inbook{Nakamura:j2000,
  author = {Nakamura, Taketsune and Yamamoto, Takahiro and Tsuchiya, Shingo and Fujio, Akihisa and Hoshino, Tsutomu and Muta, Itsuya and Oh, Sang-Soo and Ha, Hong-Soo},
  title = {Anisotropy of Critical Current and Glass-Liquid Transition Flux Density in {Bi}-2223/{Ag} Tape},
  journal = {Supercond. Sci. Technol.},

  year = {2000},
  month = {November},
  volume = 13, 
  number=11,  
  pages = {1521 - 1525}, 
  doi = {http://doi.org/10.1088/0953-2048/13/11/303}
}
Nakamura, T., Yamamoto, T., Tsuchiya, S., Hoshino, T. & Muta, I. Angular Dependence of Current Transport Characteristics in a Mixed State of Bi-2223/Ag Multifilamentary Tape [Abstract] [BibTeX] [PDF] 2000 IEEE T. Appl. Supercond., Vol. 10(1), pp. 1166 - 1169 Article DOI
Abstract: We have investigated current transport characteristics in a mixed state of Bi-2223/Ag multifilamentary tape by varying the angle between the external magnetic field and the tape surface. It was shown that the so-called glass-liquid transition magnetic field, which is an important parameter for applications of persistent current mode, as well as the critical currents, was dominated by the c-axis component (perpendicular to the tape surface) of the external magnetic field in a wide range of the field direction.
BibTeX:
@inbook{Nakamura:j2000a,
  author = {Nakamura, Taketsune and Yamamoto, Takahiro and Tsuchiya, Shingo and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Angular Dependence of Current Transport Characteristics in a Mixed State of {Bi}-2223/{Ag} Multifilamentary Tape},
  journal = {IEEE T. Appl. Supercond.},

  year = {2000},
  month = {March},
  volume = 10, 
  number=1,  
  pages = {1166 - 1169}, 
  doi = {http://doi.org/10.1109/77.828441}
}
Fuchino, S., Tamada, N., Ishii, I., Okano, M., Higuchi, N. & Hoshino, T. Hydraulic Characteristics in Superconducting Power Transmission Line [BibTeX] [PDF] 1999 ICEC17, ICEC 1998, Proc. 17th ICEC, pp. 475 - 478 Inproceedings
Abstract:
BibTeX:
@inbook{Fuchino:p1999,
  author = {Fuchino, Shuichiro and Tamada, Noriharu and Ishii, Itaru and Okano, Makoto and Higuchi, Noboru and Hoshino, Tsutomu},
  title = {Hydraulic Characteristics in Superconducting Power Transmission Line},

  publisher = {Institute of Physics Publishing},
  year = {1999},
  month = {January},


  pages = {475 - 478}, 
}
Hoshino, T., Eguchi, M., Konishi, T., Muta, I., Nakamura, T., Tsukiji, H., Noguchi, Y. & Suzuki, M. Turn Off Trigger Energy characteristics of the Superconducting Power Electronics Device (S-PED) --in Case of type D-- [Abstract] [BibTeX] [PDF] 1999 IEEE T. Appl. Supercond., Vol. 9(2), pp. 1221 - 1224 Article DOI
Abstract: S-PED means a superconducting power electronics device. We made some thermally controlled S-PED which is normally-on device. They work up to 100 Hz as a full wave rectifier. For the power supply of superconducting magnets, the flux pump can be used as SPEED (Superconducting Power Electronics Excitation Device). In this paper, we describe the turn off characteristics of one of the S-PED (type d). The relations between generated resistance, gate-trigger energy and channel current were obtained.
BibTeX:
@inbook{Hoshino:j1999,
  author = {Hoshino, Tsutomu and Eguchi, Makoto and Konishi, Takeshi and Muta, Itsuya and Nakamura, Taketsune and Tsukiji, Hiroshi and Noguchi, Yoshio and Suzuki, Morio},
  title = {Turn Off Trigger Energy characteristics of the Superconducting Power Electronics Device (S-PED) --in Case of type D--},
  journal = {IEEE T. Appl. Supercond.},

  year = {1999},
  month = {June},
  volume = 9, 
  number=2,  
  pages = {1221 - 1224}, 
  doi = {http://doi.org/10.1109/77.783520}
}
Hoshino, T., Shibayama, M., Itoh, S., Muta, I., Higuchi, N., Natori, N., Fuchino, S. & Arai, K. Conductor Pitch Effect on an Eddy Current Loss of the Superconducting Power Cable Using the Disassembled Cable ``N'' Data [Abstract] [BibTeX] [PDF] 1999 IEEE T. Appl. Supercond., Vol. 9(2), pp. 1277 - 1280 Article DOI
Abstract: The origin of the difference between measured AC loss and that of the short sample test has been studied. The axial field due to disordered pitch of conductor and shield tapes has trivial effect on the eddy current loss in the stabilizer. The displacement of the current direction on the conductor from its lay angle makes comparable eddy current loss.
BibTeX:
@inbook{Hoshino:j1999a,
  author = {Hoshino, Tsutomu and Shibayama, Masataka and Itoh, Shinsuke and Muta, Itsuya and Higuchi, Noboru and Natori, Naotake and Fuchino, Shuichiro and Arai, Kazuaki},
  title = {Conductor Pitch Effect on an Eddy Current Loss of the Superconducting Power Cable Using the Disassembled Cable ``{N}'' Data},
  journal = {IEEE T. Appl. Supercond.},

  year = {1999},
  month = {June},
  volume = 9, 
  number=2,  
  pages = {1277 - 1280}, 
  doi = {http://doi.org/10.1109/77.783534}
}
Hoshino, T., Shibayama, M., Itoh, S., Muta, I., Higuchi, N., Natori, N., Fuchino, S. & Arai, K. Conductor Pitch Effect on an Eddy Current Loss of the Superconducting Power Cable using the Disassembled Cable ``M'' Data [BibTeX] [PDF] 1999 ICEC17, ICEC 1998, Proceedings of the Seventeenth ICECICEC17, ICEC 1998, Proceedings of the Seventeenth ICEC, pp. 375 - 378 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1999,
  author = {Hoshino, Tsutomu and Shibayama, Masataka and Itoh, Shinsuke and Muta, Itsuya and Higuchi, Noboru and Natori, Naotake and Fuchino, Shuichiro and Arai, Kazuaki},
  title = {Conductor Pitch Effect on an Eddy Current Loss of the Superconducting Power Cable using the Disassembled Cable ``{M}'' Data},
  journal = {ICEC17, ICEC 1998, Proceedings of the Seventeenth ICEC},
  publisher = {Institute of Physics Publishing},
  year = {1999},
  month = {January},


  pages = {375 - 378}, 
}
Hoshino, T., Eguchi, M., Konishi, T., Muta, I., Taketsune Namakura Tsukiji, H., Noguchi, Y. & Suzuki, M. Turn Off Characteristics of the Superconducting Power Electronics Device (S-PED) [BibTeX] [PDF] 1999 ICEC17, ICEC 1998, Proceedings of the Seventeenth ICECICEC17, ICEC 1998, Proceedings of the Seventeenth ICEC, pp. 455 - 458 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1999a,
  author = {Hoshino, Tsutomu and Eguchi, Makoto and Konishi, Takeshi and Muta, Itsuya and Taketsune Namakura, Tsukiji, Hiroshi and Noguchi, Yoshio and Suzuki, Morio},
  title = {Turn Off Characteristics of the Superconducting Power Electronics Device ({S-PED})},
  journal = {ICEC17, ICEC 1998, Proceedings of the Seventeenth ICEC},
  publisher = {Institute of Physics Publishing},
  year = {1999},
  month = {January},


  pages = {455 - 458}, 
}
Nakamura, T., Hoshino, T., Muta, I., Kiss, T., Matsushita, T. & Takeo, M. Transport Characteristics in YBCO Thin Films under Applying DC and AC Currents [Abstract] [BibTeX] [PDF] 1999 Advances in Superconductivity XI, Proceedings of the 11th ISS (ISS'98)Advances in Superconductivity XI, Proceedings of the 11th ISS (ISS'98), pp. 637 - 640 Inproceedings URL
Abstract: YBa2Cu3O7-δ(YBCO)薄膜における電場対電流密度(E-J)特性とスケーリング特性をDCおよびAC電流を印加して磁場の関数として測定した。AC測定についてはlnE-lnJ曲線の磁場依存挙動がDC測定とほぼ等しくなることが分かった。10-5V/m-101V/mの電場中においてはE-J特性は磁束クリープに比べ磁束フローに支配されることが分かった。
BibTeX:
@inbook{Nakamura:p1999,
  author = {Nakamura, Taketsune and Hoshino, Tsutomu and Muta, Itsuya and Kiss, Takanobu and Matsushita, Teruo and Takeo, Masakatsu},
  title = {Transport Characteristics in {YBCO} Thin Films under Applying {DC} and {AC} Currents},
  journal = {Advances in Superconductivity XI, Proceedings of the 11th ISS (ISS'98)},
  publisher = {Springer-Verlag},
  year = {1999},
  month = {August},


  pages = {637 - 640}, 
  url = {http://sciencelinks.jp/j-east/article/199921/000019992199A0690488.php},
}
Takao, T., Torii, S., Amemiya, N., Fukui, S., Hoshino, T., Ishiyama, A., Ninomiya, A., Yamaguchi, H., Satow, T. & Tsukamoto, O. Recent Technical Trends of Superconducting Magnets in Japan - Part II: Stability and Quench Characteristics [Abstract] [BibTeX] [PDF] 1999 IEEE T. Appl. Supercond., Vol. 9(2), pp. 600 - 603 Article DOI
Abstract: The committee on applied superconducting apparatuses and characteristics of superconductors, the Institute of Electrical Engineers of japan (IEEJ) has made a data base on superconducting magnets which were built over last ten years in Japan. The outline of the data base is explained in the paper (Part I). In this paper (part II), stability and hot-spot temperature of a magnet are investigated. Minimum quench energies, minimum propagating zones, and Stekly's stability factors are calculated using the data base. Dependence of those stability parameters on the magnet scale is studied and the design trends of the stability are discussed. Hot-spot temperatures of the pool-cooled magnets at quench and energy dump process are also calculated based on the data base, and the recent trends of design rules for the quench protection are studied.
BibTeX:
@inbook{Takao:j1999,
  author = {Takao, Tomoaki and Torii, Shinji and Amemiya, Naoyuki and Fukui, Satoshi and Hoshino, Tsutomu and Ishiyama, Atsushi and Ninomiya, Akira and Yamaguchi, Hiroshi and Satow, Takashi and Tsukamoto, Osami},
  title = {Recent Technical Trends of Superconducting Magnets in {Japan} - Part {II}: Stability and Quench Characteristics},
  journal = {IEEE T. Appl. Supercond.},

  year = {1999},

  volume = 9, 
  number=2,  
  pages = {600 - 603}, 
  doi = {http://doi.org/10.1109/77.783367}
}
Tsukamoto, O., Torii, S., Takao, T., Amemiya, N., Fukui, S., Hoshino, T., Ishiyama, A., Ninomiya, A., Yamaguchi, H., Satow, T. & Members of Committee on Applied Superconducting Apparatuses and Characteristics of Superconductor Recent Technical Trends of Superconducting Magnets in Japan, part I: Magnet Data Base and Recent Progress in Magnet Winding Current Density [Abstract] [BibTeX] [PDF] 1999 IEEE T. Appl. Supercond., Vol. 9(2), pp. 547 - 552 Article DOI
Abstract: The committee on applied superconducting apparatuses and characteristics of superconductors, the Institute of Electrical Engineers of Japan (IEEJ) has made a data base on low temperature superconducting magnets which have been built over the last ten years in Japan. Based on the data base trends of magnet technology are investigated. In this paper (Part I), out-line of the data base is explained and based on the data base the recent trends of the magnet technology are investigated focusing on sizes and configurations of magnets, current density of magnet windings and conductor configurations. The stability and quench protection of magnets are also investigated in other paper (Part II)
BibTeX:
@inbook{Tsukamoto:j1999,
  author = {Tsukamoto, Osami and Torii, Shinji and Takao, Tomoaki and Amemiya, Naoyuki and Fukui, Satoshi and Hoshino, Tsutomu and Ishiyama, Atsushi and Ninomiya, Akira and Yamaguchi, Hiroshi and Satow, Takashi and {Members of Committee on Applied Superconducting Apparatuses and Characteristics of Superconductor}},
  title = {Recent Technical Trends of Superconducting Magnets in {Japan}, part {I}: Magnet Data Base and Recent Progress in Magnet Winding Current Density},
  journal = {IEEE T. Appl. Supercond.},

  year = {1999},

  volume = 9, 
  number=2,  
  pages = {547 - 552}, 
  doi = {http://doi.org/10.1109/77.783355}
}
築地 浩, 牟田 一彌, 星野 勉 & 向井 栄一 試作全超電導発電機の限界出力と励磁系の影響 [Abstract] [BibTeX] [PDF] 1999 電気学会論文誌D, Vol. 119-D(12), pp. 1471 - 1476 Article DOI
Abstract: A study on effient excitation system would be important to enhance potentials of superconducting AC generators. Based on such a concept, we have fabricated an experimental machine for actually generating the electricity with a brushless exciter system which consists of a superconducting dynamo or ``magnetic flux pump''. The fully superconducting generator has also been studied, in which both of armature and field windings are made of superconductors. We made tests for actual power generation and estimated its static electrical characteristics, resulting in 20kVA class available with not only the conventional excitation system, but also the novel brushless excitation system. The paper presents a comparison of elctrical characteristics in using the brushless excitation method and the external DC current source through brush-slipring system. And the results suggest that the brushless superconducting generator could yield higher output as compared with the conventional excitation.
BibTeX:
@inbook{Tsukiji:j1999,
  author = {築地 浩 and 牟田 一彌 and 星野 勉 and 向井 栄一},
  title = {試作全超電導発電機の限界出力と励磁系の影響},
  journal = {電気学会論文誌D},

  year = {1999},
  month = {December},
  volume = 119-D, 
  number=12,  
  pages = {1471 - 1476}, 
  doi = {http://doi.org/10.1541/ieejias.119.1471}
}
築地 浩, 牟田 一彌, 星野 勉 & 向井 栄一 多基接続形磁束ポンプによる超電導マグネットのパワーリードレス励磁 [Abstract] [BibTeX] [PDF] 1999 電気学会論文誌D, Vol. 119-D(12), pp. 1515 - 1522 Article DOI
Abstract: For exciting superconducting magnets has been used conventional power supply and power lead system. This way has some problems: heat leak into the cryogenic parts, occurrence of Joule loss in the power leads, etc. To cope with such problems, the use of superconducting magnetic flux pump has been studied. The magnetic flux pump can serve a large persistent current in superconducting magnets without switch and power leads, keeping to supply large current. However, the design method of the flux pump has not been well-known yet. Therefore, we have developed a small size magnetic fiux pump for analysis purposes to investigate its characteristics and actual performances when exciting a superconducting magnet. Furthermure, we set up a new type equipment which can connect many flux pumps compactly, so we have theoretically and experimentally examined the method to improve performances of the flux pump. As a result,we additionally derived some new important design parameters. This paper also gives a. comparison between theoletically-calculated and experimental results for the case of parallel and multi-connected flux pump devices, respectively. Further it is clarified that the multiconnection of the flux pump can improve performances.
BibTeX:
@inbook{Tsukiji:j1999a,
  author = {築地 浩 and 牟田 一彌 and 星野 勉 and 向井 栄一},
  title = {多基接続形磁束ポンプによる超電導マグネットのパワーリードレス励磁},
  journal = {電気学会論文誌D},

  year = {1999},
  month = {December},
  volume = 119-D, 
  number=12,  
  pages = {1515 - 1522}, 
  doi = {http://doi.org/10.1541/ieejias.119.1515}
}
Hoshino, T., Muta, I. & Hussein, K.H. Separately-Excited DC Motor Performances Energized by Photovoltaic Power [BibTeX] [PDF] 1998 Proceedings of ICEMProceedings of ICEM, Vol. 2, pp. 696 - 701 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1998,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Hussein, Khald Hassan},
  title = {Separately-Excited {DC} Motor Performances Energized by Photovoltaic Power},
  journal = {Proceedings of ICEM},

  year = {1998},
  month = {September 2-4},
  volume = 2, 

  pages = {696 - 701}, 
}
Hoshino, T., Eguchi, M., Konishi, T., Muta, I., Nakamura, T., Tsukiji, H., Noguchi, Y. & Suzuki, M. Turn Off Characteristics of the Superconducting Power Electronics Device (S-PED). ---in Case of Type C and Type D--- [BibTeX] [PDF] 1998 Proceedings of 1998 ICPEProceedings of 1998 ICPE, pp. 841 - 846 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1998a,
  author = {Hoshino, Tsutomu and Eguchi, Makoto and Konishi, Takeshi and Muta, Itsuya and Nakamura, Taketsune and Tsukiji, Hiroshi and Noguchi, Yoshio and Suzuki, Morio},
  title = {Turn Off Characteristics of the Superconducting Power Electronics Device ({S-PED}). ---in Case of Type {C} and Type {D}---},
  journal = {Proceedings of 1998 ICPE},

  year = {1998},
  month = {October26-31},


  pages = {841 - 846}, 
}
Taira, M., Suzuki, M., Zheng, X.-G. & Hoshino, T. Counductance Peak at Zero-Bias in Ag-SiO-Bi$_2$Sr$_2$CaCu$_2$O$_8-x$ Planar Tunnel Junctions [Abstract] [BibTeX] [PDF] 1998 J. Phys. Soc. Jpn., Vol. 67(5), pp. 1732 - 1737 Article DOI
Abstract: Two kinds of junctions were fabricated on a single crystal and a polycrystal of Bi2Sr2CaCu2Odelta-x. The tunneling conductance characteristics, G(V) were measured for the former junction at temperatures from 4.2 K to 100 K; and for the latter one at temperatures from 8.7 K to 90 K. It was found that the conductance peak (CP) at zero-bias is observed for tunneling direction perpendicular to a c-axis, but is not observed for tunneling direction parallel to a c-axis. Kashiwaya et al, theoretically predicted that the junction fabricated on a d-wave superconductor can give various G(V) characteristics scattering from a s-wave like spectrum to a d-wave like one, and has CP under certain boundary condition. In the present investigation, the measured G(V) characteristics in the high T-c Bi-system superconductor were found to qualitatively agree with the theoretical prediction by Kashiwaya et al.
BibTeX:
@inbook{Taira:j1998,
  author = {Taira, Masanori and Suzuki, Morio and Zheng, Xu-Guang and Hoshino, Tsutomu},
  title = {Counductance Peak at Zero-Bias in {Ag}-{SiO}-{Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8-x}$} Planar Tunnel Junctions},
  journal = {J. Phys. Soc. Jpn.},

  year = {1998},
  month = {May},
  volume = 67, 
  number=5,  
  pages = {1732 - 1737}, 
  doi = {http://doi.org/10.1143/JPSJ.67.1732}
}
Arai, K., Umeda, M., Agatsuma, K., Tateishi, H. & Hoshino, T. Properties of Fiber-Reinforced Superconductors Adoping Tantalum Fibers [BibTeX] [PDF] 1997 Proceedings of 15th MTProceedings of 15th MT, pp. 1032 - 1035 Inproceedings
Abstract:
BibTeX:
@inbook{Arai:p1997,
  author = {Arai, Kazuaki and Umeda, Masaichi and Agatsuma, Kou and Tateishi, Hiroshi and Hoshino, Tsutomu},
  title = {Properties of Fiber-Reinforced Superconductors Adoping Tantalum Fibers},
  journal = {Proceedings of 15th MT},

  year = {1997},
  month = {October},


  pages = {1032 - 1035}, 
}
Choi, K.-D., Hoshino, T., Tsukiji, H., Tsukiyama, M., Nishiya, T., Muta, I. & Mukai, E. Machine Constants of 30 kVA Superconducting Synchronous Motor with Rotating Field Windings [BibTeX] [PDF] 1997 Proceedings of 16th ICEC/ICMCProceedings of 16th ICEC/ICMC, Vol. 2, pp. 941 - 944 Inproceedings
Abstract:
BibTeX:
@inbook{Choi:p1997,
  author = {Choi, Kyeong-Dal and Hoshino, Tsutomu and Tsukiji, Hiroshi and Tsukiyama,Masahiro and Nishiya, Tomonori and Muta, Itsuya and Mukai, Eiichi},
  title = {Machine Constants of 30 {kVA} Superconducting Synchronous Motor with Rotating Field Windings},
  journal = {Proceedings of 16th ICEC/ICMC},
  publisher = {Elsevier Science},
  year = {1997},
  month = {April},
  volume = 2, 

  pages = {941 - 944}, 
}
Hoshino, T., Muta, I., Higuchi, N. & Natori, N. AC Loss Measurement of Bi System Multilayer Tape Superconductor for Power Transmission Cable [BibTeX] [PDF] 1997 Proceedings of 15th MTProc. MT15, pp. 1136 - 1139 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1997,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Higuchi, Noboru and Natori, Naotake},
  title = {{AC} Loss Measurement of {Bi} System Multilayer Tape Superconductor for Power Transmission Cable},
  journal = {Proceedings of 15th MT},

  year = {1997},
  month = {October},


  pages = {1136 - 1139}, 
}
毛 峡, 牟田 一彌 & 星野 勉 ゆらぎ分析による乾海苔カラー画像の特徴抽出 [Abstract] [BibTeX] [PDF] 1997 電気学会論文誌C, Vol. 117-C(2), pp. 205 - 206 Article URL
Abstract: Grading of dried seaweed by subjective sense inspection of an expert(an inspector of grade) generally includes fuzziness or ambiguity. Although our final purpose would develop an automatic grading machine of dried seaweed, this paper aims to get fundamental knowledge on how to objectively discriminate the grade of dried seaweed as a first stage. In order to know features of graded dried seaweed, first, the statistics has been taken in terms of X, Y, Z of CIE three stimulus' values and normal reflection rate R obtained from image processing equipments and so on. As results of Investigating the relation between the grade and the fundamental statistics, an average of X(color tone), an average of Y(brightness), standard deviations of X and Y have been proved to increase with a lowering of seaweed's grade. On the other hand, a normal reflection rate(gloss) has a tendency to decrease with a lowering of grade. Next, the principal component analysis which is one of the multivariate analysis was carried out so as to examine the features of discrimination by the expert again. As a result, it was shown that ranking of dried seaweed by gains of principal components has a good agreement with grading of sense inspection by the expert. Moreover, after making the criterion of each grade by discrimination analysis of Mahalanobis' generalized distance, by using test samples for verification we inspected them to be belong to which grade. As a result, the comparatively good discrimination was obtained.
BibTeX:
@inbook{Mao:j1997,
  author = {毛 峡 and 牟田 一彌 and 星野 勉},
  title = {ゆらぎ分析による乾海苔カラー画像の特徴抽出},
  journal = {電気学会論文誌C},

  year = {1997},
  month = {February},
  volume = 117-C, 
  number=2,  
  pages = {205 - 206}, 
  url = {http://ci.nii.ac.jp/naid/10002809440/},
}
Matsui, H., Zheng, X.-G., Tanaka, S., Suzukia, M. & Hoshino, T. Fabrication and Chracterization of Y124 Wires [Abstract] [BibTeX] [PDF] 1997 Physica C, Vol. 282-287, pp. 2565 - 2566 Article DOI
Abstract: Y124/Ag wires were fabricated by powder-in-tube technique using YBa2Cu4O8 and Y0.9Ca0.1Ba2Cu4O8 (Y124), respectively. For this purpose, single phase Y124 superconductors were prepared by an ambient-pressure synthesis technique which is capable of mass production. Critical transport current density, J(c), of the Y124/Ag wires was measured at various temperatures down to 15K. Further, Ag2O was added into the Y124 superconductors to enhance the critical transport current density. As a result, J(c) of the Y124/Ag wires was remarkably improved by 10 wt.O/o Ag2O addition.
BibTeX:
@inbook{Matsui:j1997,
  author = {Matsui, Hiroaki and Zheng, Xu-Guang and Tanaka, Shukichi and Suzukia, Morio and Hoshino, Tsutomu},
  title = {Fabrication and Chracterization of {Y}124 Wires},
  journal = {Physica C},
  publisher = {Elsevier},
  year = {1997},
  month = {August},
  volume = 282-287, 

  pages = {2565 - 2566}, 
  doi = {http://doi.org/10.1016/S0921-4534(97)01416-0}
}
Muta, I. & Hoshino, T. SMES System for Photovoltaic Energy [BibTeX] [PDF] 1997 Proceedings of 15th MTProceedings of 15th MT, pp. 498 - 501 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1997,
  author = {Muta, Itsuya and Hoshino, Tsutomu},
  title = {{SMES} System for Photovoltaic Energy},
  journal = {Proceedings of 15th MT},

  year = {1997},
  month = {October},


  pages = {498 - 501}, 
}
Suzuki, M., Taira, M., Zheng, X.-G. & Hoshino, T. Tunneling Spectroscopy in High Tc Y-System Ceramic Superconductor [BibTeX] [PDF] 1997 Proceedings of 16th ICEC/ICMCProceedings of 16th ICEC/ICMC, Vol. 3, pp. 1639 - 1642 Inproceedings
Abstract:
BibTeX:
@inbook{Suzuki:p1997,
  author = {Suzuki, Morio and Taira, Masanori and Zheng, Xu-Guang and Hoshino, Tsutomu},
  title = {Tunneling Spectroscopy in High {Tc} {Y}-System Ceramic Superconductor},
  journal = {Proceedings of 16th ICEC/ICMC},
  publisher = {Elsevier Science},
  year = {1997},
  month = {April},
  volume = 3, 

  pages = {1639 - 1642}, 
}
Tsukiji, H., Hoshino, T., Muta, I. & Mukai, E. Electrical Characteristics of a Fully Superconducting Brushless Generator Equipped with a Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 1997 Elect. Eng. Jpn., Vol. 120(3), pp. 64 - 72 Article DOI
Abstract: The study of efficient excitation systems is important in order to enhance the potential of superconducting ac generators. We have fabricated a model machine for generating electricity with a brushless exciter system, which consists of a superconducting dynamo or ''magnetic flux pump.'' A fully superconducting generator in which both armature and field windings are made of superconductors has also been studied. The paper presents power output tests and calculated results on transients as well as the static electrical characteristics of a model machine equipped with a magnetic flux pump when operated as a fully superconducting brushless generator in persistent current mode. (C) 1997 Scripta Technica, Inc.
BibTeX:
@inbook{Tsukiji:j1997,
  author = {Tsukiji, Hiroshi and Hoshino, Tsutomu and Muta, Itsuya and Mukai, Eiichi},
  title = {Electrical Characteristics of a Fully Superconducting Brushless Generator Equipped with a Magnetic Flux Pump},
  journal = {Elect. Eng. Jpn.},

  year = {1997},

  volume = 120, 
  number=3,  
  pages = {64 - 72}, 
  doi = {http://doi.org/10.1002/(SICI)1520-6416(199708)120:3<64::AID-EEJ7>3.0.CO;2-P}
}
Tsukiji, H., Choi, K.-D., Tsukiyama, M., Nishiya, T., Hoshino, T., Mukai, E. & Muta, I. Test of Disk Type Magnetic Flux Pump with the Abillity of High Voltage Output [Abstract] [BibTeX] [PDF] 1997 IEEE T. Appl. Supercond., Vol. 7(2), pp. 394 - 397 Article DOI
Abstract: Using a superconducting magnetic flux pump, thick power leads for a superconducting magnet could be replaced with thin string leads to excite the excitation magnet of the superconducting flux pump. We have developed a new type of flux pump with high-voltage output to shorten the charge and discharge time of-the load magnet. The test of the pump with four stacked disks as the exciter for the load magnet has been carried out. This disk type flux pump yielded 70 mV of voltage across its terminal and 10 A of current through a 85 mH load magnet which was the field winding of 20 kVA. class fully superconducting generator within 12 seconds. This output voltage of the new flux pump is about 10 times larger than that of our previous work. Moreover since it is easy to stack disks for a superconducting flux pump, the high-voltage exciter for 1 H class superconducting magnet would be expected to be made easily.
BibTeX:
@inbook{Tsukiji:j1997a,
  author = {Tsukiji, Hiroshi and Choi, Kyeong-Dal and Tsukiyama, Masanori and Nishiya, Tomonori and Hoshino, Tsutomu and Mukai, Eiichi and Muta, Itsuya},
  title = {Test of Disk Type Magnetic Flux Pump with the Abillity of High Voltage Output},
  journal = {IEEE T. Appl. Supercond.},

  year = {1997},
  month = {July},
  volume = 7, 
  number=2,  
  pages = {394 - 397}, 
  doi = {http://doi.org/10.1109/77.614512}
}
Tsukiji, H., Hoshino, T., Mukai, E. & Muta, I. Fabrication and Excitation Testing of a Fully Superconducting Brushless Generator with Magnetic Flux Pump [Abstract] [BibTeX] [PDF] 1997 Elect. Eng. Jpn., Vol. 118(4), pp. 35 - 45 Article DOI
Abstract: Development of a highly efficient excitation system is important in enhancing the potential of superconducting ac generators. A new conceptual design in which electricity is generated with a brushless exciter system using a superconducting dynamo (the magnetic flux pump) has been proposed. Research on a fully superconducting generator using both a superconducting armature and a superconducting field winding has been under way for the past 7 years. In this paper an experimental model of the machine is described and test results on brushless excitation with the magnetic flux pump, with the machine operating as a fully superconducting brushless generator with an estimated capacity of 20 kVA, are presented.
BibTeX:
@inbook{Tsukiji:j1997b,
  author = {Tsukiji, Hiroshi and Hoshino, Tsutomu and Mukai, Eiichi and Muta, Itsuya},
  title = {Fabrication and Excitation Testing of a Fully Superconducting Brushless Generator with Magnetic Flux Pump},
  journal = {Elect. Eng. Jpn.},

  year = {1997},

  volume = 118, 
  number=4,  
  pages = {35 - 45}, 
  doi = {http://doi.org/10.1002/(SICI)1520-6416(199703)118:4<35::AID-EEJ5>3.0.CO;2-O}
}
Tsukiji, H., Choi, K.-D., Tsukiyama, M., Nishiya, T., Hoshino, T., Muta, I. & Mukai, E. Test of High-Voltage Output Magnetic Flux Pump for Superconducting Magnet [BibTeX] [PDF] 1997 Proceedings of 16th ICEC/ICMCProceedings of 16th ICEC/ICMC, Vol. 2, pp. 953 - 956 Inproceedings
Abstract:
BibTeX:
@inbook{Tsukiji:p1997b,
  author = {Tsukiji, Hiroshi and Choi, Kyeong-Dal and Tsukiyama, Masahiro and Nishiya, Tomonori and Hoshino, Tsutomu and Muta, Itsuya and Mukai, Eiichi},
  title = {Test of High-Voltage Output Magnetic Flux Pump for Superconducting Magnet},
  journal = {Proceedings of 16th ICEC/ICMC},
  publisher = {Elsevier Science},
  year = {1997},
  month = {April},
  volume = 2, 

  pages = {953 - 956}, 
}
Tsukiji, H., Noguchi, Y., Hoshino, T. & Muta, I. Effect of the Excitation System on the Electrical Characteristics of a Fully Superconducting AC Generator [BibTeX] [PDF] 1997 Proceedings of 15th MTProceedings of 15th MT, pp. 736 - 739 Inproceedings
Abstract:
BibTeX:
@inbook{Tsukiji:p1997c,
  author = {Tsukiji, Hiroshi and Noguchi, Yoshio and Hoshino, Tsutomu and Muta, Itsuya},
  title = {Effect of the Excitation System on the Electrical Characteristics of a Fully Superconducting {AC} Generator},
  journal = {Proceedings of 15th MT},

  year = {1997},
  month = {October},


  pages = {736 - 739}, 
}
Hoshino, T., Muta, I., Wang, J., Tsukiji, H., Hayashi, K. & Mukai, E. Current Status of Superconducting Synchronous Motor in Saga University [Abstract] [BibTeX] [PDF] 1996 IEEE T. Magn., Vol. 32(4), pp. 2373 - 2376 Article DOI
Abstract: Since there are no iron cores in the rotor and stator windings of superconducting synchronous motors, some reactances are intrinsically smaller than the ones of conventional motors. So the low synchronous reactance would be expected to improve the torque-ampere ratio stability and the overload capacity. Two types of 30-kVA synchronous motors, such as rotating armature and rotating field have been constructed. The rotating armature type motor had been fabricated and tested. The results show the difficulty of holding a stator cryostat in a low-heat leak condition. The low synchronous impedance requires some control of the armature current and/or the motor field current. The rotating field type motor encountered a balancing problem due to the triple-pipe configuration of the helium supplier in the torque tube.
BibTeX:
@inbook{Hoshino:j1996,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Wang, Jian and Tsukiji, Hiroshi and Hayashi, Kenichiro and Mukai, Eiichi},
  title = {Current Status of Superconducting Synchronous Motor in Saga University},
  journal = {IEEE T. Magn.},

  year = {1996},
  month = {July},
  volume = 32, 
  number=4,  
  pages = {2373 - 2376}, 
  doi = {http://doi.org/10.1109/20.511350}
}
Hoshino, T., Muta, I., Tsukiji, H., Ohkubo, K. & Etoh, M. Recovery Time of Superconducting Non-Inductive Reactor Type Fault Current Limiter [Abstract] [BibTeX] [PDF] 1996 IEEE T. Magn., Vol. 32(4), pp. 2403 - 2406 Article DOI
Abstract: A superconducting fault current limiting device for electric power systems has been investigated to find out its feasibility. Nea-inductive reactor type fault current limiter has been constructed using metal superconductor. Two bifilar wound solenoids were connected in antiparallel or antiseries. On each connection, the fault current limiting test was performed by short-circuiting a resistive load suddenly. The recovery (normal-to-superconductive state transition) time after the current limiting mode has been studied using small scale model of fault current limiter for the low voltage distribution line. The results reveal that the current limiter could be operated under repetitive fault current accident which was removed within a few cycle of the limiting mode. The recovery time is a function of the dissipated energy under current limiting made. Test results are presented.
BibTeX:
@inbook{Hoshino:j1996a,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Tsukiji, Hiroshi and Ohkubo, Katsuhiko and Etoh, Masahiko},
  title = {Recovery Time of Superconducting Non-Inductive Reactor Type Fault Current Limiter},
  journal = {IEEE T. Magn.},

  year = {1996},
  month = {July},
  volume = 32, 
  number=4,  
  pages = {2403 - 2406}, 
  doi = {http://doi.org/10.1109/20.511357}
}
築地 浩, 星野 勉 & 牟田 一彌 磁束ポンプの超電導マグネット励磁特性 [Abstract] [BibTeX] [PDF] 1996 電気学会論文誌D, Vol. 116-D(2), pp. 183 - 190 Article DOI
Abstract: For exciting superconducting magnets has been used conventional power supply and power leads. This way has some problems: heat leak into the cryogenic part, occurrence of Joule loss in the power leads, etc. To overcome such problems, the use of superconducting magnetic flux pump has been studied. The magnetic flux pump can serve a permanent current mode switch and power leads to supply large current in superconducting magnets. However, the design method of the flux pump has not been known well. Therefore, we have developed a small size magnetic flux pump for analysis purposes to investigate its characteristics and actual performance when exciting a superconducting magnet. Furthermore, we have theoretically and experimentally examined the method to improve performances of the flux pump. As a result, we derived some important design parameters. This paper also gives a comparison between theoretical simulaιion and experimental results for the case of single and series-connected flux pump devices, respectively. Further it is clarified that the series-and parallel-connection of the flux pump can improve performances.
BibTeX:
@inbook{Tsukiji:j1996,
  author = {築地 浩 and 星野 勉 and 牟田 一彌},
  title = {磁束ポンプの超電導マグネット励磁特性},
  journal = {電気学会論文誌D},

  year = {1996},
  month = {February},
  volume = 116-D, 
  number=2,  
  pages = {183 - 190}, 
  doi = {http://doi.org/10.1541/ieejias.116.183}
}
築地 浩, 牟田 一彌, 星野 勉 & 向井 栄一 磁束ポンプをもつブラシレス励磁形全超電導発電機の試作と励磁実験 [Abstract] [BibTeX] [PDF] 1996 電気学会論文誌D, Vol. 116-D(4), pp. 457-464 Article DOI
Abstract: A study on highly efficient excitation system would to be important to enhance the potential of superconducting AC generators hereafter. Based on such a thought, we have fabricated a new conceptual machine for actually generating electricity with a brushless exciter system using a superconducting dynamo i.e. ``Magnetic flux pump''. Moreover, a fully superconducting generator with both of superconducting armature and fileld windings has been studied for the past seven years. The paper describes the experimental model machine and the test results on characteristics of brushless excitation using the magnetic flux pump when the machine operated as a fully superconducting brushless generator of an estimated capacity of about 20 kVA.
BibTeX:
@inbook{Tsukiji:j1996a,
  author = {築地 浩 and 牟田 一彌 and 星野 勉 and 向井 栄一},
  title = {磁束ポンプをもつブラシレス励磁形全超電導発電機の試作と励磁実験},
  journal = {電気学会論文誌D},

  year = {1996},
  month = {April},
  volume = 116-D, 
  number=4,  
  pages = {457--464}, 
  doi = {http://doi.org/10.1541/ieejias.116.457}
}
築地 浩, 星野 勉, 牟田 一彌 & 向井 栄一 磁束ポンプをもつブラシレス励磁形全超電導発電機の負荷特性実験 [Abstract] [BibTeX] [PDF] 1996 電気学会論文誌D, Vol. 116-D(11), pp. 1126 - 1131 Article DOI
Abstract: A study on effient excitation system must be important to enhance the potentia.l of superconduding AC generators further. Based on this thought, we have fabricated a model machine for generating actual eledricity with a brushless exciter system, which consists of a supercondudcting dynamo or ``magnetic flux pump''. The fully superconducting generator has also been studied, in which both of armature and field winding are made of supercondudors. The paper presents actual power output tests and calculated results in transients as well as static electrical characteristics of the model machine with the magnetic flux pump when operated as a fully superconduding brushless generator in persistent current mode.
BibTeX:
@inbook{Tsukiji:j1996b,
  author = {築地 浩 and 星野 勉 and 牟田 一彌 and 向井 栄一},
  title = {磁束ポンプをもつブラシレス励磁形全超電導発電機の負荷特性実験},
  journal = {電気学会論文誌D},

  year = {1996},
  month = {November},
  volume = 116-D, 
  number=11,  
  pages = {1126 - 1131}, 
  doi = {http://doi.org/10.1541/ieejias.116.1126}
}
林 健一郎, 大坪 昭文, 牟田 一彌 & 星野 勉 高速推論法を適用したファジィハイブリッド型制御法 [Abstract] [BibTeX] [PDF] 1995 日本機械学会論文集C編, Vol. 61(582), pp. 626 - 632 Article DOI
Abstract: An important feature of fuzzy control is that the improvement of transient characteristics in control performance and excellent robustness control can be realized easily. On the other hand, in PID control, the stability is guaranteed theoretically and high-accuracy control can be realized in the static characteristics in control performance. In an effort to combine the merits of fuzzy and PID controls, a "hybrid control method" is proposed in this paper. The method proposed here is that fuzzy and PID controls are combined in parallel. In the method, changeably, fuzzy control is used in the transient characteristic area, and PID control is used in the static characteristic area. Moreover, the smoothness of control in changes is guaranteed by practicing both changes fuzzily. Also, a "simplified indirect method" which can realize high-speed inference is used as the fuzzy control method.
BibTeX:
@inbook{Hayashi:j1995,
  author = {林 健一郎 and 大坪 昭文 and 牟田 一彌 and 星野 勉},
  title = {高速推論法を適用したファジィハイブリッド型制御法},
  journal = {日本機械学会論文集C編},

  year = {1995},
  month = {February},
  volume = 61, 
  number=582,  
  pages = {626 -- 632}, 
  doi = {http://doi.org/10.1299/kikaic.61.626}
}
Hoshino, T., Tsukiji, H., Tsukiyama, M., Muta, I. & Suzuki, M. Beginning of Superconducting Power Electronics Devices (S-PED) [BibTeX] [PDF] 1995 Proceedings of 1995 ICPEProceedings of 1995 ICPE, pp. 678 - 683 Inproceedings
Abstract:
BibTeX:
@inbook{Hoshino:p1995,
  author = {Hoshino, Tsutomu and Tsukiji, Hiroshi and Tsukiyama, Masanori and Muta, Itsuya and Suzuki, Morio},
  title = {Beginning of Superconducting Power Electronics Devices {(S-PED)}},
  journal = {Proceedings of 1995 ICPE},

  year = {1995},
  month = {October},


  pages = {678 - 683}, 
}
Hussein, K.H., Muta, I., Hoshino, T. & Osakada, M. Maximum Photovoltaic Power Tracking: an Algorithm for Rapidly Changing Atmospheric Conditions [Abstract] [BibTeX] [PDF] 1995 IEE P-Gener. Transm. D., Vol. 142(1), pp. 59 - 64 Article DOI
Abstract: As the maximum power operating point (MPOP) of photovoltaic (PV) power generation systems changes with changing atmospheric conditions (e.g. solar radiation and temperature), an important consideration in the design of efficient PV systems is to track the MPOP correctly. Many maximum power tracking (MPT) techniques have been considered in the past but techniques using microprocessors with appropriate MPT algorithms are favoured because of their flexibility and compatibility with different PV arrays. Although the efficiency of these MPT algorithms is usually high, it drops noticeably in cases of rapidly changing atmospheric conditions. The authors have developed a new MPT algorithm based on the fact that the MPOP of a PV generator can be tracked accurately by comparing the incremental and instantaneous conductances of the PV array. The work was carried out by both simulation and experiment, with results showing that the developed incremental conductance (IncCond) algorithm has successfully tracked the MPOP, even in cases of rapidly changing atmospheric conditions, and has higher efficiency than ordinary algorithms in terms of total PV energy transferred to the load.
BibTeX:
@inbook{Hussein:j1995,
  author = {Hussein, Khalid Hassan and Muta, Itsuya and Hoshino, Tsutomu and Osakada, Manabu},
  title = {Maximum Photovoltaic Power Tracking: an Algorithm for Rapidly Changing Atmospheric Conditions},
  journal = {IEE P-Gener. Transm. D.},

  year = {1995},
  month = {January},
  volume = 142, 
  number=1,  
  pages = {59 - 64}, 
  doi = {http://doi.org/10.1049/ip-gtd:19951577}
}
Hussein, K.H., Muta, I., Hoshino, T. & Osakada, M. Maximum Photovoltaic Power Flow to a Separately Excited DC Motor [Abstract] [BibTeX] [PDF] 1995 電気学会論文誌D, Vol. 115-D(10), pp. 1221 - 1228 Article DOI
Abstract: 他励直流電動機の太陽光発電による最大電力応用について述べた。
BibTeX:
@inbook{Hussein:j1995a,
  author = {Hussein, Khalid Hassan and Muta, Itsuya and Hoshino, Tsutomu and Osakada, Manabu},
  title = {Maximum Photovoltaic Power Flow to a Separately Excited {DC} Motor},
  journal = {電気学会論文誌D},

  year = {1995},
  month = {October},
  volume = 115-D, 
  number=10,  
  pages = {1221 - 1228}, 
  doi = {http://doi.org/10.1541/ieejias.115.1221}
}
Hussein, K.H., Muta, I., Hoshino, T. & Osakada, M. Charging a SMES Coil Using Photovoltaic Energy [Abstract] [BibTeX] [PDF] 1995 電気学会論文誌D, Vol. 115-D(11), pp. 1424 - 1425 Article DOI
Abstract: 太陽電池エネルギーによるSMES コイルの励磁について述べた。
BibTeX:
@inbook{Hussein:j1995b,
  author = {Hussein, Khalid Hassan and Muta, Itsuya and Hoshino, Tsutomu and Osakada, Manabu},
  title = {Charging a {SMES} Coil Using Photovoltaic Energy},
  journal = {電気学会論文誌D},

  year = {1995},
  month = {November},
  volume = 115-D, 
  number=11,  
  pages = {1424 - 1425}, 
  doi = {http://doi.org/10.1541/ieejias.115.1424}
}
毛 峡, 牟田 一彌 & 星野 勉 模糊性图像的计测数据的主成分解析 --紫菜图像的特征抽出 [Abstract] [BibTeX] [PDF] 1995 中国科学技术协会第二届青年学术年会论文集, Vol. 信息与空间科学分册, pp. 262 - 265 Article
Abstract: 現在日本で海苔の等級鑑別は、官能検査員のあいまいさを含んだ主観的な官能検査によって行われている。本研究は、乾海苔等級鑑別を自動化できるようにするための基礎研究である。まず画像処理装置などによって、等級付けれた海苔を計測し、その計測したCIE 三刺激値と正反射率を統計処理した。さらに、多変量分析の主成分分析表を使用して、海苔の等級鑑別の特徴を検討した。その結果、主成分評価の得点の順位付けは、官能検査の等級の特徴を極めてよく説明できた。同時に、データ分析の時注意すべき点も明らかにした。
BibTeX:
@inbook{Mao:j1995a,
  author = {毛 峡 and 牟田 一彌 and 星野 勉},
  title = {模糊性图像的计测数据的主成分解析 --紫菜图像的特征抽出},
  journal = {中国科学技术协会第二届青年学术年会论文集},

  year = {1995},
  month = {July},
  volume = 信息与空间科学分册, 

  pages = {262 - 265}, 
}
Muta, I., Hoshino, T. & Hayashi, K. Fundamental Design and Electrical Characteristics of Superconducting Commutatorless Motor [Abstract] [BibTeX] [PDF] 1995 Elect. Eng. Jpn., Vol. 115(1), pp. 123 - 140 Article DOI
Abstract: Since there are no iron cores in the rotor and stator windings of superconducting synchronous motors, some reactances are intrinsically smaller than those of conventional motors. Thus the low synchronous reactance would be expected to improve the torque-ampere ratio stability and the overload capacity in case of the variable-speed drive system of a load-commutated inverter due to the small armature reaction. Moreover, the low subtransient reactance may contribute to lessen the voltage stress during the shortened commutating period, especially in current source-type inverter (CSI) systems. In this paper, after presenting analytical formulas needed for a machine design, one design algorithm is described, citing one example of an experimental CSI-fed superconducting motor of 30 kVA which will be fabricated. Further, the distinguished features in its operation, as expected in the foregoing, are verified by the computer simulation study in comparison with a conventional machine in terms of a high specific power density, an extension of stable power limit, and so on.
BibTeX:
@inbook{Muta:j1995,
  author = {Muta, Itsuya and Hoshino, Tsutomu and Hayashi, Kenichiro},
  title = {Fundamental Design and Electrical Characteristics of Superconducting Commutatorless Motor},
  journal = {Elect. Eng. Jpn.},

  year = {1995},
  month = {February},
  volume = 115, 
  number=1,  
  pages = {123 - 140}, 
  doi = {http://doi.org/10.1002/eej.4391150112}
}
Muta, I., Tsutsui, Y., Tsukiji, H. & Hoshino, T. Magnetically Dynamic Performances of Superconducting DC Dynamo [BibTeX] [PDF] 1995 Journal of the Japan Society of Applied Electromagnetics and MechanicsProceedings of the Fourth Japanese and Polish Joint Seminar on Electromagnetic Phenomena Applied to Technology, June 5-7 1995, Oita, Japan, JSAEM Studies in Applied Magnetics, Electromagnetic Phenomena Applied to Technology, Supplement to Volume 4 of the Journal of the Japan Society of Applied Electromagnetics and Mechanics, Vol. 4(S), pp. 179 - 187 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1995,
  author = {Muta, Itsuya and Tsutsui, Yukio and Tsukiji, Hiroshi and Hoshino, Tsutomu},
  title = {Magnetically Dynamic Performances of Superconducting {DC} Dynamo},
  journal = {Journal of the Japan Society of Applied Electromagnetics and Mechanics},

  year = {1995},
  month = {June5-7},
  volume = 4, 
  number=S,  
  pages = {179 - 187}, 
}
Geng, N., Muta, I. & Hoshino, T. A Kind of Regulation Method for Fuzzy Control Rules [BibTeX] [PDF] 1994 Proceedings of the 3rd International Conference on Fuzzy Logic and Neural Nets and Soft ComputingProceedings of the 3rd International Conference on Fuzzy Logic and Neural Nets and Soft Computing, pp. 381 - 382 Inproceedings URL
Abstract:
BibTeX:
@inbook{Geng:p1994,
  author = {Geng, Nianfeng and Muta, Itsuya and Hoshino, Tsutomu},
  title = {A Kind of Regulation Method for Fuzzy Control Rules},
  journal = {Proceedings of the 3rd International Conference on Fuzzy Logic and Neural Nets and Soft Computing},
  publisher = {Fuzzy Logic Systems Institute},
  year = {1994},
  month = {August},


  pages = {381 - 382}, 
  url = {http://dbpia.co.kr/view/ar_view.asp?arid=1055558},
}
林 健一郎, 牟田 一彌, 星野 勉 & 大坪 昭文 ファジィ分割数が低次の場合の制御性能の改善 (ファジィ制御用シミュレータの適用) [Abstract] [BibTeX] [PDF] 1994 日本機械学会論文集C, Vol. 60(572), pp. 1315 - 1322 Article DOI
Abstract: Recently fuzzy control has been recognized to be of great usefulness in many engineering fields. However, the adjustment of fuzzy control parameters such as control rules, membership functions has been carried out by trial and error, and the definite design method of fuzzy control systems has not been established yet. In this paper, the influences of fuzzy inference methods on control performances have been examined by the simulations of a first order lag system with dead time. Moreover, the improvement of control performances in case of low-dimensional number of fuzzy labelings has been tried. Main results are as follows : (1)When the number of fuzzy labelings is low-dimension such as 3×3 divisions, control performances are dependent on fuzzy inference methods. Therefore, in case of low-dimensional number of fuzzy labelings, the selection of fuzzy inference methods is important. (2) Even in case of low-dimensional number of fuzzy labelings such as 3×3 divisions, by using the simple method of changing the height of the consequent membership function ZO, the non-linear characteristic of a fuzzy controller can be tuned and its control performances can be improved.
BibTeX:
@inbook{Hayashi:j1994,
  author = {林 健一郎 and 牟田 一彌 and 星野 勉 and 大坪 昭文},
  title = {ファジィ分割数が低次の場合の制御性能の改善 (ファジィ制御用シミュレータの適用)},
  journal = {日本機械学会論文集C},

  year = {1994},
  month = {April},
  volume = 60, 
  number=572,  
  pages = {1315 -- 1322}, 
  doi = {http://doi.org/10.1299/kikaic.60.1315}
}
Hoshino, T. & Muta, I. Load Test on Superconducting Transformer and Fault Current Limiting Devices for Electric Power System [Abstract] [BibTeX] [PDF] 1994 IEEE T. Magn., Vol. 30(4), pp. 2018 - 2021 Article DOI
Abstract: A superconducting fault current limiting transformer has been investigated to find out its feasibility. In general, the following two types of superconducting fault-current limiters could be expected: non-inductive two-port and four-port devices based on superconductive-to-normal state transition. We have investigated the transient phenomena in the transformer and then designed a 10 kVA superconducting fault current limiting transformer. First of all, in order to understand performances during quenching in the main coils of the transformer at power system faults, no-load and short-circuit tests in the auxiliary coils were performed. With the same test for the main coils and four windings, exciting conductance, susceptance and leakage impedance were estimated. Under a constant resistive load, actual load tests and sudden short-circuit tests were carried out. Test results are presented.
BibTeX:
@inbook{Hoshino:j1994,
  author = {Hoshino, Tsutomu and Muta, Itsuya},
  title = {Load Test on Superconducting Transformer and Fault Current Limiting Devices for Electric Power System},
  journal = {IEEE T. Magn.},

  year = {1994},
  month = {July},
  volume = 30, 
  number=4,  
  pages = {2018 - 2021}, 
  doi = {http://doi.org/10.1109/20.305663}
}
Hoshino, T., Muta, I., Itoh, T., Hayashi, K. & Mukai, E. Preliminary Study on a Rotating Armature Type Superconducting Motor [Abstract] [BibTeX] [PDF] 1994 IEEE T. Magn., Vol. 30(4), pp. 2026 - 2029 Article DOI
Abstract: A rotating armature type motor with a laboratory made four pole saddle shape superconducting field winding has been constructed. Cool-down tests were carried out successfully several times. By the motor operating as a generator under no load and resistive load conditions, machine constants are obtained. The air gap field with outer magnetic shield yoke is 29 \% higher than without yoke. The field coil could stand current up to 120 A. The rated terminal voltage should be 220 V for 1800 rpm (at 90 A field current). The armature coil could stand current up to 50 A, with a rated armature current value of 40 A corresponding to 15 kW at 0.98 power factor. Moreover the experimental and theoretical characteristics of the motor will be presented.
BibTeX:
@inbook{Hoshino:j1994a,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Itoh, Toshiaki and Hayashi, Kenichiro and Mukai, Eiichi},
  title = {Preliminary Study on a Rotating Armature Type Superconducting Motor},
  journal = {IEEE T. Magn.},

  year = {1994},
  month = {July},
  volume = 30, 
  number=4,  
  pages = {2026 - 2029}, 
  doi = {http://doi.org/10.1109/20.305665}
}
Hoshino, T., Muta, I. & Baba, M. Preliminary Study on Non-Inductive Reactor Type Fault Current Limiter [Abstract] [BibTeX] [PDF] 1994 Cryogenics, Vol. 34(ICEC Supplement), pp. 753 - 756 Article DOI
Abstract: A superconducting fault current limiting device for electric power systems has been investigated to find out its feasibility. Non-inductive reactor type fault current limiter has been constructed using metal superconductor. Two wires that have different critical currents were bifilar wound. Two type of connections have been tested, In the first, the pair of trigger and limiter solenoids were connected antiparallel, whereas in the second, they were connected antiseries. On each connection, the fault current limiting test was performed by short-circuiting a resistive load suddenly. After opening the load circuit a few seconds, the reclosing of the circuit was performed successfully. Then recovery time was investigated. The series type NRSFCL is selected for next research and development.
BibTeX:
@inbook{Hoshino:j1994b,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Baba, Motoharu},
  title = {Preliminary Study on Non-Inductive Reactor Type Fault Current Limiter},
  journal = {Cryogenics},

  year = {1994},
  month = {September},
  volume = 34, 
  number=ICEC Supplement,  
  pages = {753 - 756}, 
  doi = {http://doi.org/10.1016/S0011-2275(05)80177-8}
}
Hussein, K.H., Muta, I., Hoshino, T. & Osakada, M. Field and Armature Control for Separately Excited DC Motors Powered by Photovoltaic Cells [Abstract] [BibTeX] [PDF] 1994 Conference Record of the Twentyfourth IEEE Photovoltaic Specialists Conference-1994Conference Record of the Twentyfourth IEEE Photovoltaic Specialists Conference-1994, pp. 1169 - 1172 Inproceedings DOI
Abstract: In this paper, the authors have investigated, both by simulation and experimentally, the effect of matching the field and armature windings on the performance of a separately excited DC motor interfaced to two photovoltaic (PV) arrays. Special emphasis has been placed on matching the load line of the field winding which, if directly connected, intersects the I-V characteristics of the array at a voltage close to the open circuit voltage resulting in a very small excitation current and hence poor motor performance. Step-up choppers were used as impedance transformers to match the motor windings to the maximum power lines of the PV arrays. The motor was coupled to a torque meter and the step-up choppers were PWM controlled by a personal computer (PC). The importance of matching the field winding was clearly illustrated whereas matching only the armature winding did not significantly improve the system efficiency.
BibTeX:
@inbook{Hussein:p1994,
  author = {Hussein, Khalid Hassan and Muta, Itsuya and Hoshino, Tsutomu and Osakada, Manabu},
  title = {Field and Armature Control for Separately Excited {DC} Motors Powered by Photovoltaic Cells},
  journal = {Conference Record of the Twentyfourth IEEE Photovoltaic Specialists Conference-1994},

  year = {1994},
  month = {December},


  pages = {1169 - 1172}, 
  doi = {http://doi.org/10.1109/WCPEC.1994.520171}
}
毛 峡, 牟田 一彌 & 星野 勉 乾海苔のあいまい画像計測データと多変量分析による等級鑑別 [Abstract] [BibTeX] [PDF] 1994 日本ファジィ学会誌, Vol. 6(5), pp. 994 - 956 Article URL
Abstract: Grading of dried seaweed by subjective sense inspection of an expert(an inspector of grade) generally includes fuzziness or ambiguity. Although our final purpose would develop an automatic grading machine of dried seaweed, this paper aims to get fundamental knowledge on how to objectively discriminate the grade of dried seaweed as a first stage. In order to know features of graded dried seaweed, first, the statistics has been taken in terms of X, Y, Z of CIE three stimulus' values and normal reflection rate R obtained from image processing equipments and so on. As results of Investigating the relation between the grade and the fundamental statistics, an average of X(color tone), an average of Y(brightness), standard deviations of X and Y have been proved to increase with a lowering of seaweed's grade. On the other hand, a normal reflection rate(gloss) has a tendency to decrease with a lowering of grade. Next, the principal component analysis which is one of the multivariate analysis was carried out so as to examine the features of discrimination by the expert again. As a result, it was shown that ranking of dried seaweed by gains of principal components has a good agreement with grading of sense inspection by the expert. Moreover, after making the criterion of each grade by discrimination analysis of Mahalanobis' generalized distance, by using test samples for verification we inspected them to be belong to which grade. As a result, the comparatively good discrimination was obtained.
BibTeX:
@inbook{Mao:j1994,
  author = {毛 峡 and 牟田 一彌 and 星野 勉},
  title = {乾海苔のあいまい画像計測データと多変量分析による等級鑑別},
  journal = {日本ファジィ学会誌},

  year = {1994},
  month = {October},
  volume = 6, 
  number=5,  
  pages = {994 - 956}, 
  url = {http://ci.nii.ac.jp/naid/110002940408/},
}
Mao, X., Muta, I. & Hoshino, T. Grade Discrimination of Dried Seaweed by Fuzzy Image Measured Data and Multivariate Analysis [BibTeX] [PDF] 1994 Japanese Journal of Fuzzy Theory and Systems, Vol. 6(5), pp. 537 - 560 Article
Abstract:
BibTeX:
@inbook{Mao:j1995,
  author = {Mao, Xia and Muta, Itsuya and Hoshino, Tsutomu},
  title = {Grade Discrimination of Dried Seaweed by Fuzzy Image Measured Data and Multivariate Analysis},
  journal = {Japanese Journal of Fuzzy Theory and Systems},

  year = {1994},

  volume = 6, 
  number=5,  
  pages = {537 - 560}, 
}
牟田 一彌, 星野 勉 & 林 健一郎 超電導無整流子電動機の基本設計とその電気的特性 [Abstract] [BibTeX] [PDF] 1994 電気学会論文誌D, Vol. 114-D(2), pp. 197 - 206 Article DOI
Abstract: Since there are no iron cores in the rotor and stator windings of superconducting synchronous motors, some reactances are intrinsically smaller than the ones of conventional motors. So the low synchronous reactance would be expected to improve the torque-ampere ratio stability and the overload capacity in case of the variable speed drive system of a load commutated inverter due to the small armature reaction. Moreover, the low sub-transient reactance may contribute to lessen the voltage stress during the shortened commutating period, especially in current source type inverter (CSI) systems. In this paper, after presenting analytical formulas needed for a machine design, one design algorithm is described, citing one example of an experimental CSI fed superconducting motor of 30 kVA which will be fabricated. Further, the distinguished features in its operation, as expected just above, are verified by the computer simulation study in comparison with a conventional machine in terms of a high specific power density, an extension of stable power limit and so on.
BibTeX:
@inbook{Muta:j1994,
  author = {牟田 一彌 and 星野 勉 and 林 健一郎},
  title = {超電導無整流子電動機の基本設計とその電気的特性},
  journal = {電気学会論文誌D},

  year = {1994},
  month = {February},
  volume = 114-D, 
  number=2,  
  pages = {197 - 206}, 
  doi = {http://doi.org/10.1541/ieejias.114.197}
}
Muta, I., Tsukiji, H., Handa, N., Hoshino, T. & Mukai, E. The Effect of Excitation Methods on Electrical Characteristics of Fully Superconducting Generator Model [Abstract] [BibTeX] [PDF] 1994 IEEE T. Magn., Vol. 30(4), pp. 2030 - 2033 Article DOI
Abstract: We have fabricated a fully superconducting generator of 20 kW class, in which both of armature and field coils are made of superconductors. Two different types of excitation system were selected and tested: a brushless excitation method consisted of ``magnetic flux pump'' and a conventional excitation method equipped with collector ring and brushes. The paper describes the experimental machine model and the comparison of test results between the two different types of excitation methods.
BibTeX:
@inbook{Muta:j1994a,
  author = {Muta, Itsuya and Tsukiji, Hiroshi and Handa, Nobuhiro and Hoshino, Tsutomu and Mukai, Eiichi},
  title = {The Effect of Excitation Methods on Electrical Characteristics of Fully Superconducting Generator Model},
  journal = {IEEE T. Magn.},

  year = {1994},
  month = {July},
  volume = 30, 
  number=4,  
  pages = {2030 - 2033}, 
  doi = {http://doi.org/10.1109/20.305666}
}
Geng, N., Muta, I. & Hoshino, T. An Optimum Fuzzy Controller for Chinese Running Train [BibTeX] [PDF] 1993 Proc.5th International Fuzzy Systems Association World Congress, Vol. 2, pp. 1199 - 1202 Inproceedings
Abstract:
BibTeX:
@inbook{Geng:p1993,
  author = {Geng, Nianfeng and Muta, Itsuya and Hoshino, Tsutomu},
  title = {An Optimum Fuzzy Controller for Chinese Running Train},


  year = {1993},
  month = {July},
  volume = 2, 

  pages = {1199 - 1202}, 
}
Geng, N., Muta, I. & Hoshino, T. An Optimum Fuzzy Controller for Running Train [BibTeX] [PDF] 1993 Proc.1st Asian Fuzzy Systems Symposium, pp. 944 - 950 Inproceedings
Abstract:
BibTeX:
@inbook{Geng:p1993a,
  author = {Geng, Nianfeng and Muta, Itsuya and Hoshino, Tsutomu},
  title = {An Optimum Fuzzy Controller for Running Train},


  year = {1993},
  month = {November},


  pages = {944 - 950}, 
}
Geng, N., Muta, I. & Hoshino, T. A Simulation Algorithm for Optimum Operation of Running Train [BibTeX] [PDF] 1993 Proc.Japan Industry Applications Society Conference, International Session of 7th Annual Conference(J.93-41), pp. 157 - 162 Inproceedings
Abstract:
BibTeX:
@inbook{Geng:p1993b,
  author = {Geng, Nianfeng and Muta, Itsuya and Hoshino, Tsutomu},
  title = {A Simulation Algorithm for Optimum Operation of Running Train},


  year = {1993},
  month = {August~25-27},

  number=J.93-41,  
  pages = {157 - 162}, 
}
Hayashi, K., Muta, I., Hoshino, T. & Ohtsubo, A. Simulator for Evaluation of Various Fuzzy Control Methods [BibTeX] [PDF] 1993 Proc.5th International Fuzzy Systems Association World Congress, Vol. 2, pp. 949 - 952 Inproceedings
Abstract:
BibTeX:
@inbook{Hayashi:p1993a,
  author = {Hayashi, Kenichiro and Muta, Itsuya and Hoshino, Tsutomu and Ohtsubo, Akifumi},
  title = {Simulator for Evaluation of Various Fuzzy Control Methods},


  year = {1993},
  month = {July},
  volume = 2, 

  pages = {949 - 952}, 
}
星野 勉 超伝導・低温工学ハンドブック [BibTeX] 1993 , pp. 627 - 630 Inbook
Abstract:
BibTeX:
@inbook{星野勉1993,
  author = {星野 勉},
  title = {超伝導・低温工学ハンドブック},

  publisher = {オーム社},
  year = {1993},
  month = {nov},


  pages = {627 -- 630}, 
}
Hoshino, T., Muta, I. & Tanakamaru, Y. MHz Band Impedance Analysis of Oxide Superconductors [Abstract] [BibTeX] [PDF] 1992 IEEE T. Magn., Vol. 28(1), pp. 763 - 766 Article DOI
Abstract: To apply high T(c) oxide superconductor to the conductor, one has to know its bulk characteristics. Criteria such as critical temperature T(c), critical current I(c), etc. are important to design conventional superconductor. There are some difficulties to apply these criteria to oxide superconducting material. The authors are investigating on evaluation of oxide superconductors by measuring their mega-hertz band impedances. Impedance measurements were performed at 77 K and room temperature, respectively. With increase of frequency, impedance at 77 K increased from zero values at 100 kHz. Impedance locus had almost same form as that of measurements at room temperature, except its start point. As density of specimen increases, impedance locus changes its form and moves in clockwise direction. Equivalent circuit is proposed. And relationship between pinning frequency and singular frequency at room temperature is observed.
BibTeX:
@inbook{Hoshino:j1992,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Tanakamaru, Yuji},
  title = {{MHz} Band Impedance Analysis of Oxide Superconductors},
  journal = {IEEE T. Magn.},

  year = {1992},
  month = {January},
  volume = 28, 
  number=1,  
  pages = {763 - 766}, 
  doi = {http://doi.org/10.1109/20.119991}
}
Muta, I., Tsukiji, H., Hoshino, T. & Mukai, E. Electrical Characteristics of Fully Superconducting Synchronous Generator in Persistent Excitation Mode [Abstract] [BibTeX] [PDF] 1992 IEEE T. Magn., Vol. 28(1), pp. 434 - 437 Article DOI
Abstract: A brushless excitation system would be useful so as to enhance features of superconducting generators further. Based on such a concept, we have fabricated a brushless-excited superconducting generators with a superconducting dynamo i.e. ``Magnetic flux pump''. Concurrently, a fully superconducting generator in which both of armature and field coils are made of superconductors has been investigated. The paper describes the experimental machine model and the test results about electrical characteristics.
BibTeX:
@inbook{Muta:j1992,
  author = {Muta, Itsuya and Tsukiji, Hiroshi and Hoshino, Tsutomu and Mukai, Eiichi},
  title = {Electrical Characteristics of Fully Superconducting Synchronous Generator in Persistent Excitation Mode},
  journal = {IEEE T. Magn.},

  year = {1992},
  month = {January},
  volume = 28, 
  number=1,  
  pages = {434 - 437}, 
  doi = {http://doi.org/10.1109/20.119904}
}
Muta, I., Hoshino, T. & Hayashi, K. Superconducting Motor Fed with CSI [BibTeX] [PDF] 1992 Symposium on Power Electronics and Electrical Drives and Advanced Electrical Motors (``SPEEDAM'')Symposium on Power Electronics and Electrical Drives and Advanced Electrical Motors (``SPEEDAM''), pp. 99 - 104 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1992a,
  author = {Muta, Itsuya and Hoshino, Tsutomu and Hayashi, Kenichiro},
  title = {Superconducting Motor Fed with {CSI}},
  journal = {Symposium on Power Electronics and Electrical Drives and Advanced Electrical Motors (``{SPEEDAM}'')},

  year = {1992},
  month = {May},


  pages = {99 - 104}, 
}
Muta, I., Hoshino, T. & Hayashi, K. Superconducting Synchronous Motor [BibTeX] [PDF] 1992 International Aegean Conference on Electrical Machines and Power Electronics (``ACEMP'')International Aegean Conference on Electrical Machines and Power Electronics (``ACEMP''), Vol. 2, pp. 769 - 775 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1992b,
  author = {Muta, Itsuya and Hoshino, Tsutomu and Hayashi, Kenichiro},
  title = {Superconducting Synchronous Motor},
  journal = {International Aegean Conference on Electrical Machines and Power Electronics (``{ACEMP}'')},

  year = {1992},
  month = {May},
  volume = 2, 

  pages = {769 - 775}, 
}
Muta, I., Morita, Y., Hoshino, T. & Ogura, K. Preliminary Study on Superconducting Transformer and Fault Current Limiting Devices for Electric Power System [BibTeX] [PDF] 1991 Proceedings of CICEMProceedings of CICEM, pp. 12 - 15 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1991,
  author = {Muta, Itsuya and Morita, Yuzuru and Hoshino, Tsutomu and Ogura, Kazuki},
  title = {Preliminary Study on Superconducting Transformer and Fault Current Limiting Devices for Electric Power System},
  journal = {Proceedings of CICEM},

  year = {1991},
  month = {September},


  pages = {12 - 15}, 
}
Arai, K., Natori, N., Higuchi, N. & Hoshino, T. AC Loss Characteristics of Superconducting Power Transmission Cable [Abstract] [BibTeX] [PDF] 1990 11th International Conference on Magnet Technology (MT-11), Vol. 1, pp. 485-490 Incollection DOI
Abstract: Characteristics of 10 m-long Nb3Sn superconducting power transmission cables are described. Cables are designed to be suitable for power of 1 to 3 GW and are assembled using Nb3Sn superconducting tapes. Ac losses, which are of major concern in superconducting cables, is greatly dependent on the design of the cable. And it is very important to assemble cables to avoid the influence of the thermal contraction. Several superconducting cables have been assembled and tested so far1). In this paper, two cables among them are picked up, then their ac losses and assembling method are discussed. One of them(cable“N”) is assembled by the following method: The electrical insulation of the cable is composed of many pieces of tyvek paper, each of which is helically wound with an appropriate lay angle to reduce axial thermal contraction. Ac losses of this cable were reduced to about 1/5 to 1/10 of that of the other cable(cable“I”). To investigate the causes of the higher ac losses in cable“I”, it was disassembled after the ac loss measurement. Then some degraded NbgSn tapes with traces of edges of the insulator tapes and wires for measurement were found. In order to estimate the degradation of tapes, their critical currents are measured. There are some tapes whose critical currents reach less than half that the original tape.
BibTeX:
@inbook{Arai:p1989,
  author = {Arai, Kazuaki and Natori, Naotake and Higuchi, Noboru and Hoshino, Tsutomu},
  title = {{AC} Loss Characteristics of Superconducting Power Transmission Cable},

  publisher = {Springer Science $+$ Business Media},
  year = {1990},
  month = {August},
  volume = 1, 

  pages = {485--490}, 
  doi = {http://doi.org/10.1007/978-94-009-0769-0_83}
}
Hoshino, T., Muta, I. & Tanakamaru, Y. Possibility of Evaluation Method on Oxide Superconductors Using Impedance Analysis [Abstract] [BibTeX] [PDF] 1990 Cryogenics, Vol. 30(Suppliment), pp. 891 - 895 Article
Abstract: 複素インピーダンスを測定することによって, 室温で酸化物超電導体の特性を評価できる可能性を示した。経時変化, 試料密度と複素インピーダンスに相関があることを明かとした。
BibTeX:
@inbook{Hoshino:j1990,
  author = {Hoshino, Tsutomu and Muta, Itsuya and Tanakamaru, Yuji},
  title = {Possibility of Evaluation Method on Oxide Superconductors Using Impedance Analysis},
  journal = {Cryogenics},
  publisher = {Buttherworth-Heinemann},
  year = {1990},
  month = {September},
  volume = 30, 
  number=Suppliment,  
  pages = {891 - 895}, 
}
Kaneko, K., Kaneko, H., Ihara, H., Hoshino, T., Okai, T., Hirabayashi, M., Terada, N., Jyo, M. & Unoki, H. Determination of the Metallic Elements in High Tc Superconductors M-X-Cu-O (M=Ba and Sr and X=Y and La) System by Isotachophoresis Method and X-ray Fluorescence Method [Abstract] [BibTeX] [PDF] 1990 Mol. Cryst. Liq. Cryst., Vol. 184, pp. 297 - 301 Article DOI
Abstract: Molar ratios of oxide-superconductor powders which are prepared by a copreclpitation method and a solid reaction method have been determined by isotachophoresis method using a leading solution with potassium acetate and a terminal solution with tris(hydroxymethyl)aminomethane.
BibTeX:
@inbook{Kaneko:j1990,
  author = {Kaneko, Keiji and Kaneko, Hiroko and Ihara, Hideo and Hoshino, Tsutomu and Okai, Takashi and Hirabayashi, Masayuki and Terada, Norio and Jyo, Masatoshi and Unoki, Hiromi},
  title = {Determination of the Metallic Elements in High {Tc} Superconductors {M-X-Cu-O (M=Ba and Sr and X=Y and La)} System by Isotachophoresis Method and X-ray Fluorescence Method},
  journal = {Mol. Cryst. Liq. Cryst.},

  year = {1990},

  volume = 184, 

  pages = {297 - 301}, 
  doi = {http://doi.org/10.1080/00268949008031778}
}
Muta, I., Tsukiji, H., Itoh, T., Ishii, S., Hoshino, T. & Mukai, E. Superconducting Dynamo and its Application to Superconducting Generator [Abstract] [BibTeX] [PDF] 1990 Cryogenics, Vol. 30(Suppliment), pp. 749 - 752 Article
Abstract: 20 kW 以下のブラシレス全超電導発電機に用いるフラックスポンプの磁束ポンピング特性を調べるための試験結果と, 実験装置について述べた。計算値によく合致する結果が得られ, 2.9 kW の原動機動力に対して, 2.1 kW の電気出力が得られた。1500 rpm では, 19.6 kW の出力が得られることを明かとした。
BibTeX:
@inbook{Muta:j1990,
  author = {Muta, Itsuya and Tsukiji, Hiroshi and Itoh, Toshiaki and Ishii, Sadao and Hoshino, Tsutomu and Mukai, Eiichi},
  title = {Superconducting Dynamo and its Application to Superconducting Generator},
  journal = {Cryogenics},
  publisher = {Buttherworth-Heinemann},
  year = {1990},
  month = {September},
  volume = 30, 
  number=Suppliment,  
  pages = {749 - 752}, 
}
Muta, I., Tsukiji, H., Tsutsui, Y., Hoshino, T., Mukai, E. & Furukawa, T. Fully Superconducting AC Generator with Brushless Excitation System [Abstract] [BibTeX] [PDF] 1990 11th MT (MT-11), Vol. 1, pp. 568-573 Incollection DOI
Abstract: A study on efficient excitation system must be important to enhance the potential of superconducting AC generators further. After the first successful demonstration in a feasibility of magnetic-flux pump based brushless excitation system suitable for superconducting generators in 1983, we have been constructing a testing machine able to generate actual electric power. Concurrently with it, we have been studying a fully superconducting generator with both of armature and field coils made of superconductors. The paper presents the experimental machine system and its testing results about pumping-up performances of magnetic-flux pump and electrical characteristics when operated as fully superconducting brushless generator with the capacity of less than 20 kW.
BibTeX:
@inbook{Muta:p1989,
  author = {Muta, Itsuya and Tsukiji, Hiroshi and Tsutsui, Yukio and Hoshino, Tsutomu and Mukai, Eiichi and Furukawa, Tatsuya},
  title = {Fully Superconducting {AC} Generator with Brushless Excitation System},

  publisher = {Springer Science $+$ Business Media},
  year = {1990},
  month = {August},
  volume = 1, 

  pages = {568--573}, 
  doi = {http://doi.org/10.1007/978-94-009-0769-0_98}
}
Muta, I., Tsukiji, H., Itoh, T., Ishii, S., Hoshino, T. & Mukai, E. Experiment of Fully Superconducting Brushless Generator [BibTeX] [PDF] 1990 ICEMICEM, Vol. 2, pp. 616 - 619 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1990,
  author = {Muta, Itsuya and Tsukiji, Hiroshi and Itoh, Toshiaki and Ishii, Sadao and Hoshino, Tsutomu and Mukai, Eiichi},
  title = {Experiment of Fully Superconducting Brushless Generator},
  journal = {ICEM},

  year = {1990},
  month = {August},
  volume = 2, 

  pages = {616 - 619}, 
}
Muta, I., Hayashi, K. & Hoshino, T. Characteristics of Superconducting Commutatorless Motor Fed by Current Source Inverter (CSI) [BibTeX] [PDF] 1990 ICEMICEM, Vol. 2, pp. 681 - 686 Inproceedings
Abstract:
BibTeX:
@inbook{Muta:p1990a,
  author = {Muta, Itsuya and Hayashi, Kenichiro and Hoshino, Tsutomu},
  title = {Characteristics of Superconducting Commutatorless Motor Fed by Current Source Inverter {(CSI)}},
  journal = {ICEM},

  year = {1990},
  month = {August 13-15},
  volume = 2, 

  pages = {681 - 686}, 
}
Higuchi, N., Natori, N., Arai, K. & Hoshino, T. Nb$_3$Sn Superconducting Power Transmission Cable [BibTeX] [PDF] 1988 Progress in High Temperature SuperconductivityInternational Symposium on New Developments in Applied Superconductivity, Suita, Osaka, Japan, Oct. 17-19, 1988 : a supplement of annual report of Laboratory for Applied Superconductivity , Osaka University, Vol. 15, pp. 668-673 Inproceedings URL
Abstract:
BibTeX:
@inbook{Higuchi:p1988,
  author = {Higuchi, Noboru and Natori, Naotake and Arai, Kazuaki and Hoshino, Tsutomu},
  title = {{Nb$_3$Sn} Superconducting Power Transmission Cable},
  journal = {Progress in High Temperature Superconductivity},
  publisher = {World Scientific},
  year = {1988},
  month = {October},
  volume = 15, 

  pages = {668--673}, 
  url = {http://ci.nii.ac.jp/ncid/BA07008241},
}
星野 勉, 石井 格, 樋口 登 & 淵野 修一郎 Nb$_3$Snおよび酸化物超電導体を用いた1~3 GVA級超電導送電ケーブルに関する考察 [Abstract] [BibTeX] [PDF] 1988 電学誌B, Vol. 108-B(9), pp. 431 - 438 Article DOI
Abstract: Nb3Sn および高Tc 酸化物超電導体を用いた66 kV 級超電導送電ケーブルの概念設計を行なった。ヘリウム冷却のNb3Sn ケーブルについてコンパクトな設計が行えた。酸化物系超電導体の交流損失がNb3Snと同等であると仮定すると, ヘリウム冷却のケーブルよりも高電流密度の設計が可能となり, 液体窒素冷却超電導ケーブルは超電導ケーブルの経済的なブレークイーブン容量を引き下げ得る可能性を示した。
BibTeX:
@inbook{Hoshino:j1988,
  author = {星野 勉 and 石井 格 and 樋口 登 and 淵野 修一郎},
  title = {{Nb$_3$Sn}および酸化物超電導体を用いた1~3 {GVA}級超電導送電ケーブルに関する考察},
  journal = {電学誌{B}},

  year = {1988},
  month = {September},
  volume = 108-B, 
  number=9,  
  pages = {431 - 438}, 
  doi = {http://doi.org/10.1541/ieejpes1972.108.431}
}
Hoshino, T., Ishii, I., Higuchi, N. & Fuchino, S. 1 to 3 GVA Class Superconducting Power Transmission Cables with Nb$_3$Sn or Oxide Superconductor [Abstract] [BibTeX] [PDF] 1988 Elect. Eng. Jpn., Vol. 108(6), pp. 75 - 85 Article DOI
Abstract: Nb3Sn および高Tc 酸化物超電導体を用いた66 kV 級超電導送電ケーブルの概念設計を行なった。ヘリウム冷却のNb3Sn ケーブルについてコンパクトな設計が行えた。酸化物系超電導体の交流損失がNb3Snと同等であると仮定すると, ヘリウム冷却のケーブルよりも高電流密度の設計が可能となり, 液体窒素冷却超電導ケーブルは超電導ケーブルの経済的なブレークイーブン容量を引き下げ得る可能性を示した。
BibTeX:
@inbook{Hoshino:j1989,
  author = {Hoshino, Tsutomu and Ishii, Itaru and Higuchi, Noboru and Fuchino, Shuichiro},
  title = {1 to 3 {GVA} Class Superconducting Power Transmission Cables with {Nb{$_3$}Sn} or Oxide Superconductor},
  journal = {Elect. Eng. Jpn.},

  year = {1988},
  month = {December},
  volume = 108, 
  number=6,  
  pages = {75 - 85}, 
  doi = {http://doi.org/10.1002/eej.4391080608}
}
星野 勉, 佐藤 則明, 林 洋一 & 篠原 譲司 電磁界解析による電磁浮遊装置の考察 [Abstract] [BibTeX] [PDF] 1982 電学誌B, Vol. 102-B(4), pp. 219 - 226 Article DOI
Abstract: カスプコイルおよび球状試料からなる電磁浮遊系の電磁界解析を行ない, 浮遊力および加熱電力の理論式を得, 実験的にその検証を行ない以下の事を明らかにした。浮遊力, 入力電力は級数展開式で与えられ, 試料とコイルの相対位置・計上の関数, 試料半径と表皮深さの比x の関数と試料径のべき乗の積となる。カスプコイル中心では, 臨界周波数を与えるx の値は, 従来の誘導加熱で言われていた2.25 ではなく, 3.7 である。
BibTeX:
@inbook{Hoshino:j1982,
  author = {星野 勉 and 佐藤 則明 and 林 洋一 and 篠原 譲司},
  title = {電磁界解析による電磁浮遊装置の考察},
  journal = {電学誌{B}},

  year = {1982},
  month = {April},
  volume = 102-B, 
  number=4,  
  pages = {219 - 226}, 
  doi = {http://doi.org/10.1541/ieejpes1972.102.219}
}
星野 勉 電磁浮遊装置に関する基礎的研究 [BibTeX] [PDF] 1982 Phdthesis DOI URL
Abstract:
BibTeX:
@inbook{Hoshino1982,
  author = {星野 勉},
  title = {電磁浮遊装置に関する基礎的研究},


  year = {1982},
  month = {1},



  url = {http://ci.nii.ac.jp/naid/500000267735/},
  doi = {http://doi.org/10.13140/RG.2.1.2717.7841}
}
Hayashi, Y., Satoh, N., Ogura, Y. & Hoshino, T. Effects of Exciting Frequency on the Characteristics of Attractive-Type Magnetic Levitation [BibTeX] [PDF] 1981 Elect. Eng. Jpn., Vol. 99(3), pp. 66 - 73 Article DOI
Abstract:
BibTeX:
@inbook{Hayashi:j1981,
  author = {Hayashi, Youichi and Satoh, Noriaki and Ogura, Yasuhiro and Hoshino, Tsutomu},
  title = {Effects of Exciting Frequency on the Characteristics of Attractive-Type Magnetic Levitation},
  journal = {Elect. Eng. Jpn.},

  year = {1981},
  month = {March},
  volume = 99, 
  number=3,  
  pages = {66 - 73}, 
  doi = {http://doi.org/10.1002/eej.4390990309}
}
星野 勉, 佐藤 則明, 林 洋一 & 舟木 聡 カスプコイルによる電磁浮遊装置の浮遊力に関する一考察 [Abstract] [BibTeX] [PDF] 1981 電学誌B, Vol. 101-B(4), pp. 229 - 236 Article DOI
Abstract: カスプコイル中の金属試料に働く浮遊力を測定した。アルミニウム球について自重の41 % の浮遊力が得られた。浮遊力は試料半径と表皮の厚さ(表皮効果) の比に依存し, その比が10 以下では大きく変化した。試料へ入る電力及び電源入力電力に対する効率は, 測定周波数範囲で周波数にほぼ比例した。
BibTeX:
@inbook{Hoshino:j1981,
  author = {星野 勉 and 佐藤 則明 and 林 洋一 and 舟木 聡},
  title = {カスプコイルによる電磁浮遊装置の浮遊力に関する一考察},
  journal = {電学誌{B}},

  year = {1981},
  month = {April},
  volume = 101-B, 
  number=4,  
  pages = {229 - 236}, 
  doi = {http://doi.org/10.1541/ieejpes1972.101.229}
}
Hoshino, T., Satoh, N., Hayashi, Y. & Ogura, Y. An Application of the Observer to the Attractive-Type Magnetic Levitation [Abstract] [BibTeX] [PDF] 1981 Elect. Eng. Jpn., Vol. 99(4), pp. 107 - 115 Article DOI
Abstract: 従来の磁気浮上制御方式は過渡特性は良好であるが, 外乱に対してギャップ長定常偏差をなくすことが出来なかった。ギャップ長偏差の原因となる質量を帰還し, 質量と速度の推定に状態観測器を用い, ギャップ長と電流の検出のみで定常偏差を皆無とする新しい制御方式を開発し, 実験して検証を行なった。
BibTeX:
@inbook{Hoshino:j1981a,
  author = {Hoshino, Tsutomu and Satoh, Noriaki and Hayashi, Youichi and Ogura, Yasuhiro},
  title = {An Application of the Observer to the Attractive-Type Magnetic Levitation},
  journal = {Elect. Eng. Jpn.},

  year = {1981},
  month = {April},
  volume = 99, 
  number=4,  
  pages = {107 - 115}, 
  doi = {http://doi.org/10.1002/eej.4390990413}
}
Hoshino, T., Sato, N., Hayashi, Y. & Funaki, S. Levitating Force Working to Metal Specimen in Electromagnetic Levitation System Using a Cusp Coil [Abstract] [BibTeX] [PDF] 1981 Elect. Eng. Jpn., Vol. 101(2), pp. 110 - 116 Article DOI
Abstract: カスプコイル中の金属試料に働く浮遊力を測定した。アルミニウム球について自重の41 % の浮遊力が得られた。浮遊力は試料半径と表皮の厚さ(表皮効果) の比に依存し, その比が10 以下では大きく変化した。試料へ入る電力及び電源入力電力に対する効率は, 測定周波数範囲で周波数にほぼ比例した。
BibTeX:
@inbook{Hoshino:j1981b,
  author = {Hoshino, Tsutomu and Sato, Noriaki and Hayashi, Youichi and Funaki, Satoshi},
  title = {Levitating Force Working to Metal Specimen in Electromagnetic Levitation System Using a Cusp Coil},
  journal = {Elect. Eng. Jpn.},

  year = {1981},

  volume = 101, 
  number=2,  
  pages = {110 - 116}, 
  doi = {http://doi.org/10.1002/eej.4391010217}
}
林 洋一, 佐藤 則明, 小倉 靖弘 & 星野 勉 吸引形磁気浮上方式における励磁電源に位相制御整流器を用いた場合の浮上特性 [Abstract] [BibTeX] [PDF] 1979 電学誌B, Vol. 99-B(5), pp. 327 - 334 Article DOI
Abstract: 吸引形磁気浮上系の励磁制御用電力増幅器として, 単相, 三相位相制御整流器及び理想的増幅器を用いた場合について, 系の特性に及ぼす影響を理論的及び実験的に比較検討した。その結果, 小振幅及び大振幅過渡特性の点で最適極配置が明きらかとなり, この場合, 増幅器によらない過渡特性が得られた。しかし, 外乱に対する安定動作範囲は相数が少ないほど狭くなることも示した。
BibTeX:
@inbook{Hayashi:j1979,
  author = {林 洋一 and 佐藤 則明 and 小倉 靖弘 and 星野 勉},
  title = {吸引形磁気浮上方式における励磁電源に位相制御整流器を用いた場合の浮上特性},
  journal = {電学誌{B}},

  year = {1979},
  month = {May},
  volume = 99-B, 
  number=5,  
  pages = {327 - 334}, 
  doi = {http://doi.org/10.1541/ieejpes1972.99.327}
}
星野 勉, 佐藤 則明, 林 洋一 & 小倉 靖弘 吸引形磁気浮上方式に状態観測器の適用についての一考察 [Abstract] [BibTeX] [PDF] 1979 電学誌B, Vol. 99-B(8), pp. 549 - 556 Article DOI
Abstract: 従来の磁気浮上制御方式は過渡特性は良好であるが, 外乱に対してギャップ長定常偏差をなくすことが出来なかった。ギャップ長偏差の原因となる質量を帰還し, 質量と速度の推定に状態観測器を用い, ギャップ長と電流の検出のみで定常偏差を皆無とする新しい制御方式を開発し, 実験して検証を行なった。
BibTeX:
@inbook{Hoshino:j1979,
  author = {星野 勉 and 佐藤 則明 and 林 洋一 and 小倉 靖弘},
  title = {吸引形磁気浮上方式に状態観測器の適用についての一考察},
  journal = {電学誌{B}},

  year = {1979},
  month = {August},
  volume = 99-B, 
  number=8,  
  pages = {549 - 556}, 
  doi = {http://doi.org/10.1541/ieejpes1972.99.549}
}
Created by JabRef and Jab2TableHTML on 2017/04/19.