大型调相机内部故障特征及纵向零序电压保护性能分析

Analysis of Internal Fault Characteristics and Longitudinal Zero-sequence Overvoltage Protection Performance of Large-scale Condenser

大型调相机(容量为300 Mvar)实际运行中存在定子绕组匝间短路的可能,不装设匝间短路保护或匝间短路保护性能不完善将是调相机安全运行的严重隐患。文中运用"多回路分析法",对两种冷却方式大型调相机所有实际可能发生的内部故障进行了仿真分析,分析结果表明大型调相机现有主保护配置方案(完全纵差保护+纵向零序电压保护)存在较大的保护死区。进一步分析了纵向零序电压保护不能动作的故障类型,为大型调相机主保护性能的改善提供借鉴。

Large-scale condenser(300 Mvar)has the possibility of stator winding inter-turn short-circuit in practice.It will be a serious hidden danger for the safe operation of the condenser that there is no inter-turn short-circuit protection or the performance of inter-turn short-circuit protection is not perfect.The multi-loop analysis method is used to simulate and analyze all possible internal faults of the large-scale condenser with two different cooling modes.The results show that there is a large dead zone in the existing main protection configuration of the large-scale condenser(complete longitudinal differential protection+longitudinal zero-sequence overvoltage protection).The failure types of longitudinal zero-sequence overvoltage protection is further analyzed,which can provide reference for the performance improvement of the main protection configuration of large-scale condensers.