基于电压型故障特征量的发电机机端断路器非全相保护

Voltage Features Based Open-phase Protection of Generator Circuit Breaker

针对广州蓄能水电厂A厂在轻载发电工况下,发电机机端断路器(GCB)发生单相断线时,相关保护未能及时切除故障导致事故扩大的现状,利用对称分量法对GCB非全相故障进行了理论分析,并运用PSCAD软件搭建了GCB非全相故障的动态仿真计算模型。根据故障特征提出了以GCB两侧基波零序电压的相角差作为GCB非全相保护新型判据的构想,通过动模实验验证了仿真计算模型的正确性与GCB非全相保护新型判据的合理性。

In view of the failure of Guangzhou Pumped Storage Power Station A （GPSPSA） generator circuit breaker （GCB） to shave the fault during single-phase disconnection that led to expansion of the accident when the generator was running under low load, the symmetrical component method is adopted to analyze the GCB open-phase fault. The simulation model for the GCB open phase fault is built using the PSCAD software. According to the fault features, the phase angle difference of the zero sequence fundamental voltages between the two sides of GCB is assumed to be the new criterion for GCB open-phase protection. Through the experiment of the dynamic simulation system for the GCB open phase fault, the simulation model is verified to be correct and the new criterion for the GCB open-phase protection is rational.