Research on test performance and optimisation of 500 kV CVT under overvoltage

Capacitive voltage transformers (CVTs) are widely deployed in substations, used to monitor the field voltage signal, to ensure the safe operation of the power system. With the increasing voltage level of the power system, the system is affected by lightning, operating and other factors, which may cause excessive voltage in the power system, accelerate equipment aging, causing damage to power equipment. To improve the ability of the system to deal with overvoltage hazards, firstly this paper carries out operation overvoltage and lightning overvoltage tests on CVT, which added fix capacitance to improve transient responsiveness. Then, an equivalent circuit model of the shock voltage generator and CVT is built. Finally, by means of simulation, the cause of the distortion or error of the testing is analyzed, which lays the foundation for the subsequent improvement of the CVT device.