Rapid Estimation Method of Surface Electric Field Strength of the Fork-type Preformed Helical Spacer

The fork-type preformed helical spacer has been widely used in UHV transmission lines. However, due to the large surface curvature of the preformed helical wire used in the fork-type preformed helical spacer, the corona discharge phenomenon is more likely to occur than the general spacer, resulting in a more serious corona discharge problem. In this paper, the surface electric field strength of the fork-type preformed helical spacer commonly used in engineering is calculated by finite element analysis. The influence of each design parameter on the surface electric field strength of the fork-type preformed helical spacer is analyzed. The formula for calculating the surface average maximum field electric strength of the preformed helical spacer is proposed and compared with the commonly used hook-type preformed helical spacer. The research results of this paper can provide technical reference for the selection of preformed helical spacers in engineering.