温度・圧力が異なる2領域を有する高温SF₆ガス中の電子なだれ進展過程の解析的検討

抄録

High-voltage gas circuit breakers (GCBs) have been developing to reduce their size and further to use an alternative gas of SF₆ which is one of greenhouse gas. Therefore, optimization of interrupter design is so important as to improve interrupting performance with compact size and/or the alternative gas of less arc extinction capability. Recent progress of analysis can lead the optimization of GCB design for higher interrupting performance. To improve quantitative evaluation of interrupting performance, it is required to model a dielectric recovery in consideration of remaining hot gas just after current interruption. The dielectric recovery in arcing zone must be evaluated dynamically and under non-uniform condition of temperature and pressure. As the first step, development of electronic avalanche was analyzed with one-dimensional flow simulation considering 26 collisional reactions of electron, ions, and neutral particles for two regions of high-temperature and low-pressure, and low-temperature and high-pressure. In this paper, the effect of low-temperature and high-pressure gas on electronic avalanches was investigated. As a result, the higher the critical electric field is in low-temperature and high-pressure, the lower the possibility of electron avalanche development is. It is concluded that the effect of electron avalanche at a gas area with largely different regions of the critical electric fields.