摘要详情

ID / 提交时间

282 / 2024-09-14 11:12:10

标题

The study on the cold-state breakdown characteristics of different environmentally friendly gases

关键字

Environmentally friendly mixed gas; Cold breakdown characteristics; Electron energy distribution function; Ionization and attachment coefficients

主题及专题

1)Emerging HV Switching Technologies

状态

全文录用

作者

Shaoan Wang / Electric Power Research Institute of State Grid Zhejiang electric power company

Xiaohang YIN / School of Electrical Engineering ShenyangUniversity of Technology

XUJianyuan XU / Shenyang University of Technology

Tianbo Zhang / State Grid Zhejiang Electric Power Research Institute

Zhenxin GENG / Shenyang University of Technology

Yousheng JIN / School of Electrical Engineering ShenyangUniversity of Technology

摘要

C₄F₇N is a potential alternative to SF₆ gas. Researching the critical breakdown field strength of C₄F₇N and its mixed gases is of great significance for further studying their insulating properties. This paper establishes a mathematical model for the critical breakdown field strength of gases, employs a two-term approximation method to solve the Boltzmann equation, and calculates the electron energy distribution function (EEDF) for different proportions of C₄F₇N mixed gases and synthetic air under reduced electric fields ranging from 100Td to 1000Td at a temperature of 300K, The reduced ionization coefficient α/N and the reduced attachment coefficient β/N in the gas collision process were calculated, and the reduced breakdown field strengths for different proportions of C₄F₇N mixed gases and synthetic air were obtained. The study shows that when the proportion of C₄F₇N is fixed and E/N increases, the value of α/N increases while β/N decreases. The values of α/N and β/N are the highest for pure O₂ and the lowest for pure N₂, and they become saturated when E/N exceeds 300Td. The breakdown field strength of the C₄F₇N mixed gas linearly increases with the content and is affected by the O₂ content, with 2%-10% O2 being able to maintain the breakdown field strength. The breakdown field strength of synthetic air increases with the increase in O₂ content. The increase in H₂O content causes the breakdown field strength of the C₄F₇N mixed gas to decrease to a maximum of 70.3%. At 900 μL/L and 1500 μL/L of trace moisture, the breakdown field strengths reach 72.3% and 71.0%, respectively. A trace moisture content of 300 μL/L reduces the breakdown field strength of air to 85.2%, and at 1200 μL/L of trace moisture, it drops to 68.3%, with the breakdown field strength being 214.6 Td.