Numerical design of high voltage insulator structure considering SEEA charge accumulation in vacuum

A Monte Carlo simulation (MCS) method of charge accumulation based on the secondary emission electron avalanche mechanism is applied to the design of effective corrugation on an HV insulator surface. The electric field distribution on the cathode in the vicinity of a triple junction is analysed taking the charge accumulation into account. A considerable relaxation of field strength takes places due to negative charge accumulation with appropriate corrugation. The flashover voltage obtained experimentally increases as the field strength decreases. The result of MCS thus agrees well with the experimental result. This proves that the MCS method is useful for the design of high voltage insulator structures.