Under impulse voltage

the internal capacitive element in the capacitor voltage transformer is subjected to different voltages.Understanding the impulse response characteristics of capacitor voltage transformer is very important for analyzing the insulation fault of capacitor voltage transformer.Starting from the disassembly of a 500 kV capacitor voltage transformer

a distributed parameter model of capacitor voltage transformer is set up based on the measurement of the capacitor and its internal unit parameters.The response of capacitor voltage transformer to the impulse voltage in case of lightning invasion wave and closing operation of line is analyzed.It is shown by the analysis that under impulse voltage

the voltage withstood by the capacitive elements on both sides of capacitive voltage divider at high voltage side of capacitor voltage transformer is higher than other elements.In case of breakdown of capacitive element inside the capacitor voltage transformer

the voltage withstood by the normal elements at the same impulse voltage rises

which speeds up damage of capacitive element due to the impulse voltage.The analysis conclusion and the disassembly result are in agreement

which has important significance to the analysis of internal insulation damage of capacitor voltage transformer.