发电机外部“定子接地”故障分析及处理

Analysis and Treatment of Generator External ‘Stator Grounding'

阐述了一起大型发电机机端电容互感器故障导致的发电机定子接地保护动作事故的分析及处理过程,指出定子接地保护动作处理的首要原则是区分故障点位于机内还是机外,从而确定高效合理的事故处理办法。还论述了目前常用的"零序电压+三次谐波"式定子接地保护和注入式定子接地保护不能实现故障定位的问题,探讨了可能解决此问题的若干方法。

Based on the discussion of the analysis and treatment of a generator stator grounding protection action caused by large-scale generator terminal voltage transformer fault, the paper points out that the first principle of generator stator grounding protection treatment is to distinguish the fault point is located inside or outside the generator, and thereby determine the reasonable and efficient accident treatment measures. The paper also discusses the problem that the commonly used ＂zero-sequence voltage plus 3rd harmonic＂ type stator grounding protection and injection type stator ground protection can＇t obtain the information of fault location, and then explores several methods may to solve this problem.