2023 Fiscal Year Final Research Report

Development of novel high-performance dielectric gas supporting next-generation dc power transmission

Research Project

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Project/Area Number	19K03806
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 14030:Applied plasma science-related
Research Institution	Muroran Institute of Technology
Principal Investigator	Satoh Kohki 室蘭工業大学, 大学院工学研究科, 教授 (50235339)
Project Period (FY)	2019-04-01 – 2024-03-31
Keywords	ガス絶縁 / SF6代替 / 電子輸送係数 / 電子衝突断面積 / 解離断面積 / HFO-1234ze(E)
Outline of Final Research Achievements	The properties of HFO-1234ze(E) are investigated as a candidate for a insulating gas required in next-generation electric power transmission. It is shown that C2F6, C2HF, C2H2, C2F4, C2H2F2, C2HF3, C2HF5, C3HF3, and C3HF5 are generated during atmospheric pressure discharge in HFO-1234ze(E) - Ar mixed gas. We also found that the curvy increase of the ion current in fragment measurement near the threshold is not due to the energy distribution of thermal electrons emitted from a filament, but is due to the collision probability distribution between electrons and gas molecules. Further, a method to properly determine the threshold of dissociation collisions is proposed. When measuring the electron transport coefficient of an insulating gas, low current flow requires to consider the charging time of the measurement capacitor. It is found that this consideration does not affect the ionization coefficient and drift velocity, but that it affects the diffusion coefficient.
Free Research Field	高電圧工学
Academic Significance and Societal Importance of the Research Achievements	エネルギーのスマート化の加速により電力消費量が増加し，更なる低損失長距離送電への要求から高性能ガス絶縁媒体が求められている。現在，絶縁ガスには SF6 が用いられているが，温暖化係数が非常に高く代替ガスが求められている。絶縁ガスの特性は，親ガスとそのフラグメントによって決まるため、両者を把握することが重要である。本研究では絶縁ガスとしてHFO-1234ze(E)を対象とし、大気圧放電中の分解生成物を調査するとともに、電子衝突によるフラグメントを調査している。さらに、フラグメント生成のしきい値を正確に決定する手法についても提案し、HFO-1234ze(E)の特性が更に詳細に理解できた。