Finite Element Analysis of Charge Injection and Transport in a Dielectric Liquid

Unipolar and bipolar space charge injection and propagation is analyzed under simplified linear and Fowler-Nordheim charge injection conditions for parallel plane or needle-sphere electrodes stressed by a step voltage. To verify our finite element numerical method, we first tested parallel plane electrodes with a simplified linear charge injection law for unipolar space charge propagation that showed good agreement with older closed form theoretical analysis. Finally, we analyzed tip-sphere electrodes for bipolar space charge propagation including Langevin recombination using finite element analysis.