高压电动机综合保护整定计算的探讨

SETTING PRINCIPLE OF INTEGRATED PROTECTION FOR HIGH VOLTAGE MOTOR

简要叙述高压电动机微机综合保护功能判据 ,重点探讨综合保护的整定计算原则。其中对电流速断保护在电动机启动后定值是启动时定值一半的原则 ,F- C回路负序过流考虑断相后的保护定值 ,提出了不同看法。对过热保护、堵转保护、过负荷电流保护等定值的计算 ,根据实际运行经验 ,探讨了其较为合理的计算方法 ,最后对综合保护提出了进一步完善的改进意见。

The operation experience of high voltage motor used in power plant shows that the damage of motors in most cases was caused by bearing and mechanical faults, so the conventional current quick operating protection can not effectively protect the motors from these faults. The authors propose that the new integrated protection should be set properly considering reasonable starting current and starting time, at the same time, the second stage positive sequence current protection should be set considering maximum load current and suitable time to avoid the mal-operation during starting. The negative sequence current protection in F-C circuit, locked rotor protection and overheating protection are also discussed.