Investigation of simple graded permittivity solid spacer shape by electrode modification on gas insulated switchgear

Abstract

It was investigated and proved that the Functionally Graded Material (FGM) as an insulation material for high voltage applications are able to relax the electric field concentration around the high voltage electrode and along the gas-insulator surface. Based on the previous numerical analysis, it was proved that the FGM spacer, which permittivity has gradually changed, with the modification of a spacer configuration by the Design of Experiment (DOE) showed considerable maximum electric field reduction in comparison with a conventional spacer which has uniform permittivity. However, it is hard to apply a gradual permittivity variation in the FGM spacer for a real product processing due to its complicated shape. Thus, through this paper, it is proceeded to change the electrode shape in the gas insulated switchgear in order to increase the possibility of real FGM insulator manufacturing. To achieve the goal, the optimization processes are used to modify the both shape of electrode and FGM spacer on a commercial gas insulated switchgear configuration. Consequently, the insulation capability of the switchgear with the optimally designed FGM spacer can be efficiently improved.