水电机组轴电流保护误动原因的分析

Cause Analysis on Maloperation of Shaft Current Protection of Hydropower Generating Units

发电机轴电流对机组危害较大,针对水电机组轴电流保护误报警问题,做了一定的分析和探讨,提出了硬件、软件相结合的滤波措施,以采样基波作为保护判据,消除了低频干扰,现场静态、空载及负荷试验证明效果良好,解决了机组轴电流保护误报警问题。

The shaft current of generator does great harm to units. The paper analyzes and discusses on false alarm of shaft current protection of hydropower generating units and proposes a filtering measure which combines software with hardware. The measure takes the sampled fundamental wave as criteria for protection and eliminates the glitch. The measure turns out to be effective in field static test, no load test and load test and it can handle the false alarm of shaft current protection of units.