Self-consistent modeling of electrical tree propagation and PD activity

The self-consistent model of electrical tree propagation and partial discha rge (PD) activity within growing tree channels is presented. The local elec tric held and the damage accumulation in the dielectric material surroundin g the channels govern the tree growth. The damage increment is proportional to the energy release in the channels due to PD. The electric field distri bution is determined by the charge deposition within the tree structure and the electrode geometry. The charge distribution changes within the channel s during PD. PD starts when the electric field along the channels exceeds a threshold inception value and stops when the field falls below the thresho ld quenching value. The numerical three-dimensional realization of the mode l has been used for simulation of electrical treeing with sinusoidal and tr iangular voltages in a needle-plane geometry. The spatial-temporal dynamics of the tree growth and phase-resolved characteristics of the PD have been studied for various magnitudes of the applied voltage. The simulation resul ts have been compared with experimental data given in the literature.