Electric field analysis of typical surface insulation configurations in vacuum

Under high voltage stress, the electric strength of surface insulation system configured with compound dielectrics is far lower than the breakdown strength of its insulating material, which is closely related to its electric field distribution. The electric field distributions of typical surface insulation structures in vacuum was simulated, such as the parallel flat plate, planar and stick-plate electrode systems. Such influential factors were considered as the gap of electrode-dielectric contact, the coning angle of circular truncated cone, the height of planar electrode, and the dielectric constant of insulator, etc. The simulation results reveal that the contact gap results in the enhancement of local electric field and the change of its direction, more serious distortion of electric field will occur with larger contact gap, conical angle and dielectric constant or smaller electrode height. This conclusion will be helpful to the design of surface insulation structure in vacuum.