Impact of Voltage Transformer Fault on Excitation Regulator

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.