750kV川-黄-贺线路分闸过电压事故分析

750 kV银川东变电站7522断路器分断后,由于不对称电磁振荡叠加,在750 kV川-黄-贺线路上产生了分闸过电压。研究表明,此过电压幅值不高,持续时间不长,不会影响相关的750 kV电气设备的安全运行。但由于川-黄-贺线过压保护出口整定时间较短,因此切空线过电压造成了川-黄-贺线黄河变电站、贺兰山变电站相应的800 kV断路器发生跳闸。为此建议适当延长川-黄-贺线过压保护出口整定时间。同时建议对于新建的750 kV输电线路在投运前,进行投切断路器过程的过电压测试,为线路过压保护的合理整定提供科学依据。

The operating overvoltage failures analysis in 750 kV Yinchuan Eastern Substation,Huanghe Substation and Helan Substation transmission line

After 7522 circuit breaker of 750 kV Yinchuan Eastern Substation broke,the operating overvoltage appeared in Yin-Huang-He 750 kV transmission line because of the unsymmetrical electromagnetic oscillations superimposition.The study shows that the amplitude of the overvoltage is not high,the duration is not long,which will not influence the safe operation of the related 750 kV electrical equipment,but the overvoltage protection outlet setting time is too short,the unloaded line tripping overvoltage caused 800 kV circuit breaker trip in Huanghe Substation and Helan Substation.So the paper suggests properly lengthens the overvoltage protection outlet setting time of Yin-Huang-He transmission line,and makes overvoltage test in process of switching circuit breaker before the new built 750 kV transmission line put into commission,provides scientific basis for the rational setting of the transmission line overvoltage protection.