Optimal Design of Spacer for High Voltage Gas Insulated Switchgear

This study describes the optimal design of 3 phase epoxy spacer to improve the electrical and mechanical performance of high voltage Gas Insulated Switchgear (GIS). Epoxy spacer is one of the significant components in GIS, functioning as supporting conductor, compartmentalizing GIS into separated units and insulating between conductor and enclosure of GIS. With the need of compact-sized GIS and higher gas pressure in GIS, electrical safety as well as mechanical reliability of epoxy spacer should be taken into account. Especially in case of 3 phase spacer, it is more complicated to obtain robust design because both phase-to-phase and phase-toearth insulation should be considered. In this paper, threedimensional finite element analysis is applied to calculate electric field and mechanical stress. A (μ+λ) Evolution Strategy (ES) is employed as optimization method. Design variables of epoxy spacer are selected for minimizing the maximum electric field strength and maximum mechanical stress on the spacer. Finally, optimal solutions for spacer is obtained and compared with the results of the prototypes.