A simulation model for PD patterns in voids with consideration of PD discharge areas

Based on the concept of the variable discharge areas of partial discharges (PDs), a numerical calculation method was put forward to simulate the PD pattern. In addition the critical field for PD occurrence and the residual field, a new parameter E_s is introduced in this model to determine the discharge area. The probability for discharge propagation along the surface is assumed to be determined by the field distribution on the surface. The discharge propagation is terminated when the field in the perimeter segments of the PD paths on the surface becomes less than E_s. By increasing E_s transition to swarming pulsive microdischarges (SPMD) is obtained. The rabbit-like PD pattern can be simulated if assuming surface conductivity of the void. Unlike the conventional simulation models that attribute the different PD behavior to the different probability for PD occurrence, this model might provide a new approach to connect the PD behavior with the surface condition of the insulating materials (e.g. the surface conductivity, the property for discharge propagation on the surface etc.)