Analytical Study on Electron Avalanche in Two Different Temperature and Pressure Regions for High-temperature SF6 Gas

High-voltage circuit breakers require a thorough understanding of the dielectric phenomena in the arcing region under non-uniform temperature and pressure conditions. As the first step towards reaching this understanding, we analyzed the development of electron avalanche using one-dimensional flow simulation considering 26 collisional reactions between electrons, ions, and neutral particles in a high-temperature/low-pressure region and a low-temperature/high-pressure region. The higher critical electric field in the latter region resulted in a lower possibility of electron avalanche development. The effect of electron avalanche in a gas area with largely different critical electric fields can be calculated by using the proposed analysis model for electron avalanche development.