Research on Micrometer-Scale Discharge Phenomena Induced by Tiny Metal Particles

• Project/Area Number: 18K13740
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Yokohama National University
• Principal Investigator: Iwabuchi Hiroyuki 横浜国立大学, 大学院工学研究院, 助教 (50757341)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: 真空遮断器 / 電界電子放出 / 放電 / 真空放電 / シミュレーション / PIC-MCC法 / 遅発性放電 / 二次電子放出

Outline of Final Research Achievements

In this research, non-sustained disruptive discharge (NSDD) which occurs after interrupting the current in a vacuum circuit breaker was investigated. The breakdown process was investigated through following three steps: evaporation of metal particles, diffusion of metal vapor, and the breakdown. The numerical simulation suggests that the time scales of evaporation, diffusion, and the breakdown were 10μs, 10μs, 10ns, respectively. The results indicated that the time delay of late breakdown process is mainly determined by the generation of moving metal particles.

Academic Significance and Societal Importance of the Research Achievements

事故発生時の電流遮断や系統の復旧には高性能な遮断器が必要不可欠である。従来では SF6ガスを用いて開極時のアークを消弧するガス遮断器が一般的であったが、SF6ガスの温暖化係数が非常に大きいことから真空遮断器の小型化、高性能化が注目されるようになった。しかし、真空遮断器の遮断試験において、アーク消弧後に短時間で絶縁を回復する絶縁破壊(NSDD：Non-Sustained Disruptive Discharge)の発生が報告されている。本研究の成果はNSDDの発生に与える電界電子放出電流の影響を定量的に評価したもので、高性能な真空遮断器の開発に不可欠な重要な知見を与えるものである。

Research Products

• [Journal Article] Late Breakdowns Caused by Microparticles After Vacuum Arc Interruption (2019)
  • Author(s): Ejiri Haruki、Kumada Akiko、Hidaka Kunihiko、Taguchi Yuki、Inada Yuki、Yamano Yasushi、Iwabuchi Hiroyuki、Kaneko Eiji
  • Journal Title: IEEE Transactions on Plasma Science Volume: 47 Issue: 8 Pages: 3392-3399
  • DOI: 10.1109/tps.2019.2917379
  • Peer Reviewed
• [Journal Article] Breakdown Phenomena across Micrometer Scale Surface Gap under Negative Voltage Application (2019)
  • Author(s): Hiroyuki Iwabuchi, Tsutomu Oyama, Akiko Kumada and Kunihiko Hidaka
  • Journal Title: IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION Volume: 印刷中
  • NAID: 120006781966
  • Peer Reviewed
• [Presentation] Effect of Field Electron Emission Current on Breakdown Phenomenon under Low Pressure (2019)
  • Author(s): Y.Kitabayashi, H.Iwabuchi and T.Oyama
  • Organizer: International Conference on Electrical Engineering 2019
  • Int'l Joint Research
• [Presentation] 低気圧下における電界電子放出に起因した絶縁破壊現象 (2019)
  • Author(s): 北林優祐, 岩渕大行, 大山力
  • Organizer: 平成31年電気学会全国大会
• [Presentation] Breakdown Phenomenon across mm-scale gap with thin cavity (2018)
  • Author(s): H. Iwabuchi, Y. Nakaso and T. Oyama
  • Organizer: GD2018
  • Int'l Joint Research
• [Presentation] Late Dielectric Breakdown Phenomenon Caused by Microparticles Released after Current Interruption (2018)
  • Author(s): Y. Hachiman, F. Oshiro, Y. Nagayo, E. Kaneko, Y. Inada, Y. Taguchi, Y Yamano, M. Maeyama, Y. Kitabayashi, H. Iwabuchi, H. Ejiri, A. Kumada and K. Hidaka
  • Organizer: ISDEIV2018
  • Int'l Joint Research