Simulations of Electric Field Dynamics for DC Partial Discharge Sequences

This paper is intended to contribute to research into the interpretation of PD measurements under DC conditions. A simple PD system comprising of a cylindrical air filled void surrounded by polypropylene based copolymers is considered. A DC ramp of 1 kV/s reaching 10 kV was applied to the system and PD activity recorded from the start of the ramp for 104 seconds. An equivalent simulation model was constructed and used to investigate the influence of different phenomena. It was demonstrated that surface conduction is likely to play a crucial role in the applied field dynamics, leading to the cessation of PD activity. It also appears that charge deployed by PDs must be undergoing rapid recombination in order to support the high repetition rate in the first 1000 s of the experiment. The future work required to develop a full PD activity model is discussed.