一起发电机转子接地保护动作事件的探讨

Discussion on a Grounding Protection Action Event of Generator Rotor

对于某核电站#2机组在运行过程中曾发生因发电机转子一点接地故障最终导致机组解列的事件,经过分析发现是转子接地检测装置中的电刷脏污,造成测量出的转子接地电阻低于保护跳闸的整定值,从而导致保护装置误动。针对发电机转子一点接地保护出口设置提出了改进建议,针对转子一点接地保护误动引发跳机的事件研究出了解决措施,为同行电厂提供了借鉴。

In the operation of a nuclear power plant#2 unit in China,there was an event that caused the unit to be dismissed due to a ground fault of the generator rotor.After analysis,it is found that the brush was dirty in the rotor grounding detection device.The measured rotor grounding resistance waslower than the setting value of the protection tripresulting in malfunction of the protection device.In this paper,the improvement suggestions for the one-point grounding protection exit of the generator rotor wereput forward.Aiming at the accident of tripping caused by the misoperation of one-point grounding protection of rotor,the solution measures were studied,which could be used for reference by the same power plant.