Numerical investigation of insulation conductivity effect on electrical treeing

A self-consistent model of electrical tree propagation and partial discharge activity within growing tree channels is developed. The electric field and the damage accumulation in the dielectric material surrounding the channels govern tree growth. The damage value is proportional to the amount of energy which is released in the channels due to partial discharges. The electric field distribution is determined by the charge placement within the insulator and electrode geometry. The charge distribution changes due to partial discharges and the conduction of the dielectric material. The numerical three-dimensional realisation of the model has been used to investigate the influence of the value of dielectric materials conductivity on electrical treeing under sinusoidal voltage in the needle-plane geometry. The temporal-spatial and phase-resolved characteristics of partial discharge activity have been studied for perfect and poor-performance insulators.