Design and Verification of Self-Voltage Sharing Vacuum Interrupter for High-Voltage GIS

Abstract

Achieving compact design with high insulation performance is a critical challenge for vacuum interrupters (VIs) in eco-friendly gas-insulated switchgear (GIS). This article addresses the severe nonuniform of potential distribution across the multiple floating shields (MFSs) in VIs for GIS by proposing a novel self-voltage sharing capacitor pattern (SSCP), which integrates grading rings and ring capacitors on the exterior of the VI. The simulation results show that, compared with the conventional VI, the SSCP improves the potential distribution on the MFS by 21.64%, 13.07%, and 6.05%. Furthermore, it achieves a 24.60% reduction in the maximum internal electric field strength and a 35.21% reduction in the external field. To validate these findings, an experimental platform was established for a 145-kV VI. The experimental results regarding the influence of grading capacitance on potential distribution are consistent with the simulation trends. Specifically, with a grading capacitance of 2000 pF, the MFS potential distribution reaches 74.95% $U$ , 48.87% $U$ , and 22.63% $U$ , closely approximating the ideal linear distribution. This research provides a theoretical basis and an optimized structural design for enhancing the insulation performance of high-voltage VIs in GIS.