电压互感器故障对励磁调节器的影响分析

Impact of Voltage Transformer Fault on Excitation Regulator

针对励磁调节器的电压互感器(voltage transfor mer,VT)故障进一步扩大会造成发电机失磁停机的问题,以南海发电一厂2号发电机WKKL-2000型微机励磁调节器为例,通过分析VT单相和两相断线时调节器的动作情况,指出该VT的接线未遵循双重配置原则而存在安全隐患,提出具体的改进措施:2组VT交叉接线;VT二次绕组接单相空气开关;修改VT反馈电压计算软件。仿真验算和实际运行效果表明实施改进措施后,能避免VT故障造成发电机失磁停机事故发生。

The further deterioration of voltage transformer fault of excitation regulator may result in excitation loss and shutdown of generator.Accordingly,with WKKL-2000 microcomputer-based excitation regulator of Generator 2 in Nanhai A Power Plant for instance,the operation of regulator during single/double phase breaking of voltage transformer is analyzed.It is indicated that the wiring of the voltage transformer fails to follow the dual-configuration principle and has safety risk.Specific measures for improvement are proposed,which include wiring two voltage transformers crosswise,connecting the secondary winding of voltage transformer to single-phase air switch,and amending the feedback voltage calculation software of voltage transformer.Simulation and practical operation show that the improving measures can prevent excitation loss and shutdown of generator caused by voltage transformer fault.