发电机低励失磁保护Ⅲ段误动原因分析和预防措施

Analysis on reasons of incorrect tripping of excitation-loss protection section III of generator and preventive measures

针对发电机失磁保护Ⅲ段保护误动事故比较多的情况,对发电机失磁保护Ⅲ段保护跳闸原因进行了分析,失磁保护误动作的原因是失磁保护Ⅲ段外部系统电压开入量在机组方式发生改变后,未能及时改变保护接线方式。提出了防止失磁保护误动作的预防措施,以确保设备安全运行。

The incorrect tripping accident of the excitation-loss protection section III for the generator was occurred frequently.The reasons of the incorrect tripping of the excitation-loss protection section III of the generator were analyzed.According the analysis,the reason of the incorrect tripping of excitation-loss protection is that the operation mode of the unit primary system had been changed,but the binary input connection of excitation loss protection section III did not be modified relevantly.The measures to prevent incorrect tripping of excitation-loss protection were put forward,which are helpful for ensuring the safe operation of the devices.