The equivalent circuit for capacitive voltage transformer (CVT) exhibits significant high-frequency response errors and substantial deviation in results. To address this issue

a comprehensive study was conducted on a 500 kV CVT

utilizing both experimental and simulation methods. This study involved parameterizing the equivalent circuit of each component and structure of CVT

developing a high frequency equivalent circuit model that includes parasitic parameters. The transfer function of the CVT was calculated

and the transient coupling capacitance was analyzed for its transfer characteristics. The impact of parasitic parameters on the frequency response characteristics of the transient coupling capacitance was also discussed. The research findings indicate that the proposed high frequency equivalent circuit model reduced the amplitude and phase angle errors of the CVT frequency response under high-frequency excitations by 106.2% and 49.4%

respectively. It was also observed that an increase in the parasitic inductance of the CVT’s transient coupling capacitance leads to a decrease in the frequency of the peaks and troughs of the transfer curve

while increasing their amplitude. Additionally

the frequency distribution error of the phase points shifts to lower frequencies. The results help to understand the high frequency response characteristics of CVT under lightning and operating overvoltage.