In order to reduce the transient impulse current amplitude through capacitor voltage transformer（CVT） while switching fixed series capacitors platform

we established an equivalent model using a disconnector to switch fixed series capacitors platform by ATP-draw. The simulation results show that decreasing the rated capacitance of CVT and seriesing inductance or resistance in CVT can reduce the amplitude of transient impulse current effectively. First

we developed the UHV CVT with a rated capacitance of 2 000 pF

and built the broadband equivalent circuit of it. Then

we chose five sets of damping elements with different parameters

compared with the calculation results and measuring results

verified the rationality of calculation model

and confirmed the parameters of damping elements. At last

we set up an impulse current testing system under lightning impulse voltage

and measured the transient impulse current through the UHV CVT with a rated capacitance of 2 000 p F and damping device integrated developed in this paper and the UHV CVT with a rated capacitance of 5 000 pF used in UHV engineering under the same lightning impulse overvoltage. The measurement results indicate that applying the lightning impulse overvoltage with a amplitue of 1 550 kV and wave-head time/full wave time is 5.5/67 μs on UHV CVT

the amplitude of transient impulse current through the CVT developed in this paper is 0.82 kA

and the amplitude of transient impulse current through the CVT used in UHV engineering is 2.66 kA. The study results indicate that the small rated capacitance UHV CVT series with damping device developed in this paper can decrease the amplitude of transient impulse current effectively. Its reliability under the transient state will be improved.