Simulation and Test of Potential Distribution for 750 kV Insulator String

Based on the configuration of insulators and grading rings on 750 kV transmission lines,this paper analyzes the potential distribution of insulator string with the finite-element method,and compares the influences of position depth,diameter,and tube diameter of grading ring,as well as dielectric coefficient of insulation material,on the potential distribution.Moreover,potential distribution of ‘I’ insulator string with typical configuration is measured at the UHV outdoor test field of SGEPRI,and the result is compared with the calculating one.This study demonstrates that position depth and diameter of grading ring remarkably influence the potential distribution of insulator string,the influences of tube diameter of grading ring and dielectric coefficient of insulation material are slight,and the maximal distributing voltage from test is approximately equal to that from calculation.