Research on Operating Overvoltage Measurement Based on Capacitive Current Method

Transient voltage not only causes power system insulation accidents to occur, but also threatens the stable operation of power equipment. However, the current method for measuring transient voltage is difficult to achieve real-time monitoring, so it is urgent to improve the monitoring capability of transient voltage. Capacitor Voltage Transformers are widely used as measurement devices for systems with voltage levels above 66 kV. But when the primary system is subjected to transient voltage disturbance, it will lead to serious distortion of the CVT secondary output voltage and affect the accuracy of transient voltage measurement. This paper explores the feasibility and accuracy of using capacitive current method to measure transient voltage. The simulation model of overvoltage measurement of no-load line under all working conditions is built in ATP, and the feasibility of measuring overvoltage by capacitive current method is verified by simulation analysis. This method is compared with the secondary side voltage inverse algorithm. The results show that the error of overvoltage reduction based on capacitive current method is smaller than that of secondary side voltage inverse algorithm and meets the requirements of measurement standard. Therefore, it is feasible to use the capacitive current method to measure transient voltage. This method can provide a reference for accurate transient voltage measurement using CVT.