To improve the potential distribution of the EHV or UHV MOA usually requires a comprehensive measurethat the grading rings are taken in the high-voltage side

while grading capacitors are enforced on the arrester elements.Although the grading capacitors can improve voltage distribution of the arrester

it may be difficult to test and itsimproper parameters will bring insecurity. Since the capacitance of capacitor column is much smaller than that of MOVcolumn

the potential distribution is unevenly

and some capacitors’ electric load rate is very high

which will causesits accelerated aging until it is destroyed. This paper builds 3 D model of 1 000kV MOA capacitor column put inoperation by means of the finite element analysis method to get the conclusion that the capacitance and the configurationof the capacitors and gaskets make influence on the potential distribution of the capacitor column. In particular

thewithstand voltage of the capacitor at both ends of the arrester element near the flange needs to be concerned. Thereferenceisprovidedforthereasonableselectionoftheparametersofcapacitorcolumnfor 1000kVMOA.