Electric Field Regulation of Insulator Interface by FGM With Conductivity for Superconducting-GIL

Abstract

This paper focuses on the problem of electric field distortion along the insulator surface in superconducting gas insulated transmission line (S-GIL). In order to homogenize the electric field distribution, a simplified design of the insulator with surface conductivity gradient was proposed. The surface conductivity profile of the S-GIL insulator was designed as linear and nonlinear distribution separately. The effects of different parameter selections on the electric field and conduction loss of the S-GIL insulators were analyzed by a finite element method. Results show that the insulator with surface functional graded material (SFGM) can significantly suppress the electric filed distortion at the triple junction in the S-GIL. In addition, the insulator with nonlinear surface conductivity distribution possesses a superior electric-field nonuniformity factor as low as approximate 1.1 while the leakage current is in an acceptable range simultaneously. The insulator with SFGM shows great potential in the real S-GIL system.