Improvement of Exciter Insulation Monitoring Scheme in a Nuclear Power Plant

Excitation system of nuclear Power Station is very important for nuclear Power Station, and its capability directly affects the safety of units and power grid.The cables of the double-ended injection type(using two cables) of the Exciter insulation monitoring device can occur phase-to-phase short fault. When changed to single-ended injection type(only using one cable), the Exciter insulation monitoring device can work normally. On the one hand, the phase-to-phase short circuit is eliminated, and then the unit shutdown caused by loss excitation fault of excitation system can be avoided.Based on the MATLAB/Simulink software, the excitation system is modeled and simulated. Through the ground fault simulation research of cable, Exciter-pole, + pole, midpoint and other places, it is proved that adding single-ended injection insulation monitoring device to Exciter can monitor the insulation state of excitation system. The simulation model can accurately reproduce the dynamic process of excitation system of the nuclear Power Station.