Simulation Analysis and Improvement Design of Electric Field Distribution for Shielding Device in UHV Converter Station Indoor DC Yard

In recent years, ultrahigh-voltage direct current (UHVDC) project has become an important direction of power system development and application. In UHVDC converter station, corona discharge may occur if the maximum electric field of metal electrode surface reaches corona electric field. The reasonable design of shielding device for different equipment in the converter station can not only effectively ensure the safety and stability operation of the system but also reduce the operation and maintenance cost. The shape and structure of different equipment are having large difference for ±800kV UHVDC project indoor DC yard, and the zero potential wall and roof are presented and increase the surface electrical field. The filter capacitor of DC yard has a large number of components which needs high requirement for internal insulation coordination. In this paper, a 3-D finite element simulation model of filter capacitor in UHVDC project indoor DC yard was established by using COMSOL. The potential and electric field distribution of filter capacitor shielding devices were calculated and analyzed. Based on the permitted value requirement, the electrode shape was continuously optimized. The research results of this paper could provide references for development and optimization design of filter capacitor in UHVDC project.