发电机失磁保护误动实际案例分析

由于发电机失磁会对整个电力系统造成极大的损失,因此发电机都会失磁保护,但是现场中发电机失磁保护的正确动作率不高,因此,为了提高发电机失磁保护动作的准确性,选择以一起额定电压为20kv,额定功率为300MW的发电机失磁保护的实际误动事故为例,通过对其误动事故的研究,探讨分析了避免其误动的方法,提出在电压判据中增加三相低电压判据,同时其TV断线在实现闭锁时采用记忆方式等等措略。依此对发电机失磁保护进行重新整定后,保护的动作可靠性极大提高。此经验非常值得推广。

Example Analysis of Generator Field Loss Protection Malfunction

As a result of the generator in the power system will cause a great loss,so the generator will be loss of field protection,but loss of excitation protection of generator′s correct action rate is not high in fact,therefore,in order to improve the accuracy of loss of excitation protection of generator′s correct action rate,this paper selects with rated voltage of 20kV,rated power of 300MW generator magnetic actual protection misoperation accident as an example,through the research of its misoperation accident,find the method to avoid misoperation.proposed in the voltage criterion in three-phase low voltage criterion,while its TV disconnection in the realization of atresia using memory way and so on.The reliability of protection is improved greatly,after the factory resetting the loss of excitation protection of generator.This experience is worth to popularize.