CONFERENCE

  1. M. Ishihara, K. Umetani, and E. Hiraki, “Impedance Matching to Maximize Induced Current in Repeater of Resonant Inductive Coupling Wireless Power Transfer Systems,”in 2018 IEEE Energy Conversion Congress and Exposition (ECCE), in USA, 2018.

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  2. M. Ishihara, K. Umetani, and E. Hiraki, “Improving Robustness Against Variation in Resonance Frequency for Repeater of Resonant Inductive Coupling Wireless Power Transfer Systems,” in 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), Riga in Latvia, 17-21 Sept. 2018.

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  3. K. Kamaeguchi, K. Umetani, and E. Hiraki, “Application of Automatic Resonant Frequency Tuning Circuit to Induction Heating System,” in 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe), Riga in Latvia, 17-21 Sept. 2018.

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  4. M. Hataya, K. Kamaeguchi, E. Hiraki, K. Umetani, T. Hirokawa, M. Imai, and S. Sadakata, “Verification of the reduction of the copper loss by the thin coil structure for induction cookers,” in Proc. IEEE Intl. Power Electron. Conf. (IPEC2018), Niigata, Japan, May 2018, pp. 410–415.

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  5. A. Konishi, K. Umetani, and E. Hiraki, “High-frequency self-driven synchronous rectifier controller for WPT systems,” in Proc. IEEE Intl. Power Electron. Conf. (IPEC2018), Niigata, Japan, May 2018, pp. 1602–1609.

  6. M. Ishihara, K. Umetani, and E. Hiraki, “Automatic resonance frequency tuning method for repeater in resonant inductive coupling wireless power transfer systems,” in Proc. IEEE Intl. Power Electron. Conf. (IPEC2018), Niigata, Japan, May 2018, pp. 1610–1616.

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  7. M. Noah, J. Imaoka, Y. Ishikura, K. Umetani, and M. Yamamoto, “Review of current balance mechanism in multiphase llc resonant converters,” in Proc. IEEE Intl. Sym. Ind. Electron. (ISIE2018), Cairns, Australia, Jun. 2018, pp. 1030–1036.

  8. T. Kusumi, T. Hara, K. Umetani, and E. Hiraki, “Theoretical derivation of phase current profile for switched reluctance motors to suppress radial force ripple and torque ripple,” in Proc. IEEE Intl. Sym. Ind. Electron. (ISIE2018), Cairns, Australia, Jun. 2018, pp. 1037–1042.

  9. R. Matsumoto, K. Aikawa, A. Konishi, K. Umetani, and E. Hiraki, “Evaluation of impact of parasitic magnetic coupling in PCB layout on common source inductance of surface mount package,” in Proc. IEEE Intl. Conf. Power Electron. Drive Syst., Honolulu, USA, Dec. 2017, pp. 559–566.

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  10. M. Ishihara, K. Umetani, and E. Hiraki, “Elucidation of quasi-duality between series-series and series-parallel topologies of resonant inductive coupling wireless power transfer systems,” in Proc. IEEE Intl. Conf. Power Electron. Drive Syst., Honolulu, USA, Dec. 2017, pp. 674–679.

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  11. Y. Tanaka, N. Nanato, M. Kondo, T. Niwase: Study on Configuration of a Single-phase Air-core Bi2223 High Temperature Superconducting Transformer for a Large AC Current Supply, 30th International Symposium on Superconductivity, December 13 - 15, 2017, Tokyo, Japan

  12. T. Ono, T. Adachi, T. Yamanishi, N. Nanato: Protection System for Normal Transitions in a Single-phase Bi2223 Full Superconducting Transformer by the Active Power Method under Flowing Various Frequency Current, 30th International Symposium on Superconductivity, December 13 - 15, 2017, Tokyo, Japan

  13. H. Kumagai, N. Nanato: High Resolution Location of Normal Transitions in A High Temperature Superconducting Coil by Capacitor Type Voltage Terminals, 30th International Symposium on Superconductivity, December 13 - 15, 2017, Tokyo, Japan

  14. S. Tanaka, S. Tenkumo, N. Nanato, Study on a Magnetic Flux Detection Coil for Detection of Normal Transitions in a Hybrid Single-phase Bi2223 Superconducting Transformer by the Active Power Method, 30th International Symposium on Superconductivity, December 13 - 15, 2017, Tokyo, Japan

  15. T. Koyama, T. Honjo, M. Ishihara, K. Umetani, and E. Hiraki, “Simple self-driven synchronous rectifier for resonant inductive coupling wireless power transfer,” in Proc. IEEE Intl. Telecommunications Energy Conf., Gold Coast, Australia, Oct. 2017, pp. 363–368.

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  16. T. Shirakawa, K. Umetani, and E. Hiraki, “Application of extremum co-energy principle for homogenizing current distribution in parallel-connected windings in transformers: design optimization of winding turn allocation among winding layers,” in Proc. European Conf. Power Electron. Appl. (EPE2017), Warsaw, Poland, Sept. 2017, pp. 1–10.

  17. M. Noah, S. Endo, S. Kimura, M. Yamamoto, J. Imaoka, K. Umetani, and E. Hiraki, “An investigation into a slight-variation of the transformer effective permeability in LLC resonant converter,” in Proc. European Conf. Power Electron. Appl. (EPE2017), Warsaw, Poland, Sept. 2017, pp. 1–7.

  18. T. Kusumi, T. Hara, K. Umetani, E. Hiraki : "Simple analytical derivation of magnetic flux profile eliminating source current ripple and torque ripple of switched reluctance motors for electric vehicle propulsion", 2017 IEEE Applied Power Electronics Conference and Exposition (APEC) pp. 3142 - 3149 (2017)

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  19. K. Aikawa, T. Shiida, R. Matsumoto, K. Umetani, E. Hiraki : "Measurement of the common source inductance of typical switching device packages", 2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia (IFEEC 2017 - ECCE Asia), pp. 1172 - 1177 (2017)

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  20. T. Ozaki, H. Nakaido, K. Umetani, E. Hiraki, T. Ikenari, and S. Kawano, “Compact three-phase AC inductor network for PFC converter using magnetic coupled technique,” in Proc. Annu. Conf. IEEE Ind. Electron. Soc. (IECON2017), Beijing, China, 2017, pp. 958–963.

  21. K. Itakura, H. Kakemizu, H. Nakaido, K. Umetani, E. Hiraki, T. Ikenari, and S. Kawano, “Soft-switching technique applicable to capacitive load for resonant inverter of plasma generator,” in Proc. Annu. Conf. IEEE Ind. Electron. Soc. (IECON2017), Beijing, China, 2017, pp. 1556–1562.

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  22. R. Kadowaki, N. Nanato: Detection Method of Normal transitions in a High Temperature Superconducting Coil wound with a plurality of YBCO superconductors by the Active Power Method and H-coils, 29th International Symposium on Superconductivity, November 13 - 15, 2016, Tokyo, Japan

  23. K. Okura, N. Nanato, Yasunobu Kumagai, Hiroki Aoyama: Locating of Normal Transitions in A Bi2223 High Temperature Superconducting Coil by Using Capacitor Type Voltage Terminals and the Active Power Method, 29th International Symposium on Superconductivity, November 13 - 15, 2016, Tokyo, Japan

  24. S. Nakamura, N. Nanato, S. Tanaka: Detection of Normal Transitions in a Hybrid Single-phase Bi2223 High Temperature Superconducting Transformer by using the Active Power Method and a Magnetic Flux Detection Coil, 29th International Symposium on Superconductivity, November 13 - 15, 2016, Tokyo, Japan

  25. N. Koide, N. Nanato, T. Ono, T. Adachi: Protection System for Normal Transitions in a Single-phase 1 kA Class Bi2223 High Temperature Superconducting Transformer by Using the Active Power Method, 29th International Symposium on Superconductivity, November 13 - 15, 2016, Tokyo, Japan

  26. N. Kishi, N. Nanato, Y. Tanaka, M. Kondo: Development of A large AC Current Supply with A Single-phase Air-core Bi2223 High Temperature Superconducting Transformer, 29th International Symposium on Superconductivity, November 13 - 15, 2016, Tokyo, Japan

  27. Y. Isshiki, K. Umetani, S. Sakai, S. Higashino, M. Yoshino, Y. Hayashi, and E. Hiraki, “Fractal-like geometry for improving heat dissipation of heat sinks,” in Proc. Intl. Forum Heat Transfer (IFHT2016), Sendai, Japan, Nov. 2016, IFHT2016-1866.

  28. W. Martinez, S. Endou, K. Nanamori, S. Kimura, M. Noah, M. Yamamoto, J. Imaoka, and K. Umetani, “Three-phase LLC resonant converter with integrated magnetics,” in Proc. IEEE Energy Conversion Congr. Expo. (ECCE2016), Milwaukee, USA, Sept. 2016.

  29. R. Matsumoto, K. Umetani, and E. Hiraki, “Optimization of the balance between the gate-drain capacitance and the common source inductance for preventing the oscillatory false triggering of fast switching GaN-FETs,” in Proc. IEEE Energy Conversion Congr. Expo. (ECCE2017), Cincinnati, USA, Sept. 2016, pp. 405–412.

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  30. M. Noah, K. Umetani, S. Endo, H. Ishibashi, J. Imaoka, and M. Yamamoto, “A Lagrangian dynamics model of integrated transformer incorporated in a multi-phase LLC resonant converter,” in Proc. IEEE Energy Conversion Congr. Expo. (ECCE2017), Cincinnati, USA, Sept. 2016, pp. 3781–3787.

  31. Y. Sugihara, K. Nanamori, S. Ishiwaki, Y. Hayashi, K. Aikawa, K. Umetani, E. Hiraki, and M. Yamamoto, “Analytical investigation on design instruction to avoid oscillatory false triggering of fast switching SiC-MOSFETs,” in Proc. IEEE Energy Conversion Congr. Expo. (ECCE2017), Cincinnati, USA, Sept. 2016, pp. 5113–5118.

  32. N. Mostafa, S. Kimura, S. Endo, M. Yamamoto, J. Imaoka, K. Umetani, and W. Martinez, “A novel three-phase LLC resonant converter with integrated magnetics for lower turn-off losses and higher power density,” in Proc. IEEE Appl. Power Electron. Conf. (APEC2017), Tampa, FL, USA, Mar. 2016, pp. 322–329.

  33. T. Hara, T. Kusumi, K. Umetani, E. Hiraki : "A simple behavior model for switched reluctance motors based on magnetic energy", 2016 IEEE 8th International Power Electronics and Motion Control Conference (IPEMC-ECCE Asia), pp. 109 - 115 (2016)

  34. T. Koyama, T. Honjo, K. Umetani, E. Hiraki : "Lagrangian derivation and analysis of a simple equivalent circuit model of wireless power transfer system with dual transmitting resonators", 2016 18th European Conference on Power Electronics and Applications (EPE'16 ECCE Europe), pp. 1 - 10 (2016)

  35. T. Shirakawa, G. Yamasaki, K. Umetani, E. Hiraki : "Copper loss analysis based on extremum co-energy principle for high frequency forward transformers with parallel-connected windings", IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, pp. 1099 - 1105 (2016)

  36. T. Kusumi, T. Hara, K. Umetani, E. Hiraki : "Simple control technique to eliminate source current ripple and torque ripple of switched reluctance motors for electric vehicle propulsion", IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, pp. 1876 - 1881 (2016)

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  37. T. Shirakawa, G. Yamasaki, K. Umetani, E. Hiraki : "Extremum co-energy principle for analyzing AC current distribution in parallel-connected wires of high frequency power inductors", 2016 19th International Conference on Electrical Machines and Systems (ICEMS), pp. 1 - 6 (2016)

  38. T. Honjo, T. Koyama, K. Umetani, E. Hiraki : "Novel receiving coil structure for improving efficiency and power transfer capability of resonant inductive coupling wireless power transfer", 2016 19th International Conference on Electrical Machines and Systems (ICEMS), pp. 1 - 6 (2016)

  39. M. Hataya, Y. Oka, K. Umetani, E. Hiraki, T. Hirokawa, M. Imai : "Novel thin heating coil structure with reduced copper loss for high frequency induction cookers", 2016 19th International Conference on Electrical Machines and Systems (ICEMS), pp. 1 - 6 (2016)

  40. Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto : "Passive regenerative turn-off snubber composed of two diodes and a capacitor for two-phase interleaved boost chopper", 2015 IEEE International Telecommunications Energy Conference (INTELEC), pp. 1 - 6 (2015)

  41. Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto : "Non-isolated interleaved high step-up converter with reduced voltage multiplier stages and a regenerative turn-off snubber", 2015 IEEE Energy Conversion Congress and Exposition (ECCE), pp. 125 - 132 (2015)

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  42. Shinya Kurachi, Naoki Yamamoto, Hiroaki Yamada, Toshihiko Tanaka, Eiji Hiraki, Yukiharu Yamada, Tatsuya Nagao, Yasuhiro Miyake, Yujiro Noda : "High-frequency induction heating for tiny foreign metals", 2015 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia), pp. 2203 - 2208 (2015)

  43. Kazuhiro Umetani, Eiji Hiraki, Masayoshi Yamamoto : "Passive regenerative turn-off snubber composed of two diodes and a capacitor for two-phase interleaved boost chopper", 2015 IEEE International Telecommunications Energy Conference (INTELEC), pp. 1 - 6 (2015)

  44. N. Nanato, K. Nishiyama, S. Hesaka, K. Okura: Locating of Normal Transitions in a High Temperature Superconducting Coil by Non-Destructive Voltage Detection Method, 27th International Symposium on Superconductivity, November 25 - 27, 2014, Tokyo, Japan

  45. N. Nanato, Y. Kobayashi, N. Koide, S. Nakamura, N. Kishi: Detection and Protection System for Normal Transitions in a Single-phase High Temperature Superconducting Transformer by Using the Active Power Method, 27th International Symposium on Superconductivity, November 25 - 27, 2014, Tokyo, Japan

  46. Tint Soe Win, Yoshihiro Hisada, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee : "Novel, simple reactive power control strategy with DC capacitor voltage control for active load balancer in three-phase four-wire distribution systems", 2014 IEEE Energy Conversion Congress and Exposition (ECCE), pp. 3916 - 3921 (2014)

  47. Tint Soe Win, Yoshihiro Hisada, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto, Seong Ryong Lee : "Reactive power control strategy based on DC capacitor voltage control for active load balancer in three-phase four-wire distribution systems", 2014 International Power Electronics Conference (IPEC-Hiroshima 2014 - ECCE ASIA), pp. 3292 - 3297 (2014)

  48. Keisuke Yoshizawa, Toshihiko Tanaka, Eiji Hiraki, Masayuki Okamoto : "MHz-class high-frequency soft-switching GaN-based inverter for wireless power transmission via electromagnetic resonance", 2014 International Power Electronics and Application Conference and Exposition, pp. 451 - 455 (2014)