本研究の今後の課題について，以下に項目ごとに示す。
A. ノイズと通信信号のタイミングに着目した電磁障害対策手法の検討
本研究では，降圧チョッパ回路のスイッチングタイミングと CAN 通信に おける信号読み取りタイミングに着目し，dv/dt制御ゲート駆動回路を用いた 電磁障害抑制手法およびTSCの開発を行った。いずれの対策手法についても 電磁障害の抑制に有効であるが，アプリケーションによっては適用できない 場合がある。例えば，dv/dt 制御ゲート駆動回路については，CAN 通信の通 信レートが比較的低い場合に有効であり，通信レートが高い場合は定常的に スイッチング速度が遅くなるためその優位性が損なわれる。そのため，アプ リケーションごとに適切な電磁障害抑制手法を適用する必要がある。今後は アプリケーションを明確にしたうえで，より多岐にわたる電磁障害抑制手法 の検討を行いたい。
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B. FF-PWCを適用したTSCをフィードバック制御と統合
TSC を適用することで降圧チョッパ回路の出力電圧に発生する減衰振動
をFF-PWCにより抑制できることを明らかにした。しかし，本研究では降圧
チョッパ回路の制御をデューティ比一定としたため，出力電圧・電流のフィ ードバック制御を含めた検証を行っていない。FF-PWC の実用性を示すため にはそれらの検討が必要不可欠であると考えている。
C. インバータ回路に適用可能な電磁障害対策手法の開発
本研究では降圧チョッパ回路が CAN 通信にもたらす電磁障害を研究対象 として様々な検討を行った。降圧チョッパ回路は電力変換回路の中で最も基 本的な方式の一つであり，基礎的な検討に最適であった。しかし，電磁障害 対策手法の実用性を示すためには，インバータ回路等のより多用されている システムで検討を行う必要がある。
D. 高速通信プロトコルに適用可能な電磁障害対策手法の開発
CAN 通信は一般的に自動車の駆動系および安全装置など信頼性が要求さ れるシステムの通信に用いられ，比較的通信速度が遅く設定されている。し かし近年，自動運転制御の搭載やインフォテイメントの拡充が進んでいるた
め，Ethernet等の高速・広帯域通信規格が多く採用されている。したがって，
CAN 通信だけではなく，Mbps あるいは Gbps 級の通信規格に対しても電磁 障害抑制手法の検討が必要不可欠である。
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研究業績
(1) 学術雑誌等
＜査読有＞
1) 白井 諒, 清水 敏久,「電力変換回路が CAN 通信にもたらす電磁障害の 対策手法」, 電気学会論文誌D, 電気学会, Vol. 138, No. 8, 2018
2) Ryo Shirai, Toshihisa Shimizu, “Study of EMI Caused by Buck Converter on Controller Area Network,” IEEJ Journal of Industry Applications（査読2回 目）
(2) 国際会議における発表
＜口頭・査読有＞
1) 〇Ryo Shirai, Toshihisa Shimizu, “Study of EMI Caused by Buck Converter on Controller Area Network,” IEEE ECCE ASIA 2018, No. 0160, Japan, May 2018.
2) 〇Ryo Shirai, Toshihisa Shimizu, “Failure protection for controller area network against EMI emitted by buck converter,” 2019 Annual IEEE Applied Power Electronics Conference and Exposition, Anaheim, CA, USA, March 2019.
＜ポスター・査読有＞
3) 〇Ryo Shirai, Toshihisa Shimizu, “Study of Electromagnetic Disturbance of Buck Chopper Circuit into Controller Area Network Communications,” IEEE workshop on electronic power transmission and distribution, E—poster session no. 11, Denmark, November 2017.
＜ポスター・査読無＞
4) 〇Ryo Shirai, Toshihisa Shimizu, “Study on Electromagnetic Disturbance of Buck Chopper Circuit into Controller Area Network Communications,”
Symposium on semiconductor power conversion, JP3, Taiwan, October 2017.
(3) 国内学会・シンポジウム等における発表
＜口頭・査読無＞
1) 〇白井 諒, 清水 敏久,「電解コンデンサの浮遊容量に起因する EMI ノ イズの解析」,平成28年電子デバイス・半導体電力変換合同研究会, EDD— 16—057, SPC—16—144, 福岡, 2016年11月
2) 〇白井 諒, 清水 敏久, 福本 聡, 松崎 頼人, 許斐 康司,「半導体電力変 換回路が CAN 通信にもたらす電磁干渉解析に向けた基礎検討」, 平成
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29年電気学会全国大会, 4—141, 富山, 2017年3月
3) 〇白井 諒, 清水 敏久,「半導体電力変換回路が CAN 通信にもたらす電 磁干渉解析に向けた基礎検討」, 首都大学東京エネルギーインテグリテ ィーシステム研究センターシンポジウム, 東京, 2017年3月
4) 〇白井 諒, 清水 敏久,「電力変換回路が CAN 通信にもたらす電磁障害 の解析」, 平成29年電気学会産業応用部門大会, R1—1, 北海道, 2017年8 月
5) 〇白井 諒, 清水 敏久,「電力変換回路が CAN 通信にもたらす電磁障害 を対象とした新たなEMC対策手法の基礎検討」, 平成29年半導体電力 変換回路・モータドライブ合同研究会, SPC—17—134, MD—17—085, 和歌山, 2017年9月
6) 〇白井 諒, 清水 敏久, 松崎 頼人, 福本 聡,「電力変換回路の制御通信 に生じる電磁障害」, 平成30年電気学会全国大会, 4—114, 福岡, 2018年 3月
7) 〇白井 諒, 清水 敏久,「EMI 抑制を実現する降圧チョッパ回路と CAN の協調制御」, 平成30年電気学会産業応用部門大会, 1—74, 神奈川, 2018 年8月
8) 〇白井 諒, 清水 敏久,「降圧チョッパ回路が CAN 通信にもたらすディ ファレンシャルモードおよびコモンモード電磁障害の解析と対策手法 の実験検証」, 平成30年半導体電力変換回路・モータドライブ合同研究 会, SPC—18—127, MD—18—087, 佐賀, 2018年9月
(5) 特許等
1) 「コンデンサのノイズ低減回路および電源装置」特願: 2017—085213（出 願中）
(6) その他（受賞歴等）
1) 平成29年電気学会全国大会優秀論文発表賞受賞
2) 平成30年パワーエレクトロニクス動画コンテスト会員優秀賞 3) 日本学術振興会特別研究員（DC1）採用内定