Simulating surface charge dynamics

Surface charge dynamics can play an important role in electric field distributions in both AC and DC insulation systems. In this paper the theory behind surface charge dynamics is introduced with a particular focus on the calculation of surface divergence; an operator which is used to determine movement of charge constrained to a surface. A detailed discussion of the model implementation is provided and validated against an analytical solution. Surface charge dynamics in AC and DC insulation systems are then investigated. Assuming the measurement data in the literature is representative it is demonstrated that surface currents have the capability to significantly alter electric field distributions in voids, even over the timescales of an AC cycle.