High frequency finite element analysis of electromagnetic radiation due to partial discharges in high voltage equipment

Measuring partial discharge (PD) activity in high voltage plant is a well established technique used to monitor insulation integrity. A partial discharge is a surge of electrons within a dielectric due to ionisation caused by the electric field and it is a sign of insulation degradation or overstressing. The acceleration of electrons creates electromagnetic radiation. This paper studies the high frequency characteristics of this radiation by considering a current transformer as an example, building on previous work which presented the optimum locations for antennas. Simulations based on the finite element method have been conducted. The results obtained have been used together with laboratory experiments to compare and expand the simulations. This paper describes these experiments and draws its conclusions based on their comparison, and indicates the effect of resonant frequencies on the receiving frequency spectra.