SF_6断路器重合闸后开断瞬态恢复电压的研究

Research of SF_6 Circuit Breaker Transient Recovery Voltage after Reclosing

针对高压断路器重合闸于故障状态后的开断过程,依托特高压交流输电系统,对断路器重合闸后二次开断瞬态恢复电压(TRV)进行了研究。首先对重合闸前后两次开断暂态过程进行理论分析,再根据流注理论气体临界击穿判据及不同开距下的断路器电场分布,建立合闸预击穿电弧模型,并利用电磁暂态仿真程序ATP/EMTP,计算了故障后第一次开断及重合闸后二次开断TRV,同时研究了重合闸相角和故障类型及位置对TRV的影响。研究结果表明,重合闸后二次开断TRV峰值及上升陡度(RRRV)均高于第一次开断,开断难度增大;对于近区单相接地故障,重合闸相角为60°时,RRRV达到2.81 k V/μs(标准3 k V/μs);需要加以限制。

According to the circuit breaker breaking process after reclosing in fault state, this paper investigates transient recovery volt- age of the second break after reclosing based on the UHV. According to the gas breakdown criterion and the circuit breaker electric field distribution, a pre-breakdown arc model is established. With ATP/EMTP program, transient recovery voltage in the first break and the second break are calculated. The result shows that the magnitude and the rise rate of the recovery voltage in the second break are higher. The maximum RRRV in single phase grounding fauh can reach 2. 81 kV/μs （ standard 3 kV/μs） with a 60° reclosing an- gle, which needs to be restricted.