Numerical model for assessing the impact of AC ripple voltage on the space charge accumulation inside solid thin film samples

Abstract

A numerical model is investigated to determine the effect of AC ripple superimposed on DC voltage on the space charge accumulation inside one layer solid thin film polymer. The simulation of space charge was based on a non-linear, electric field dependent, non-polar charge transport model with the additional provision for homocharge and hetero-charge accumulation within the insulating material. The space charge accumulation and electric field distribution were calculated for three different cases. In the first case, the applied voltage was pure DC, while in the second and third cases the ratio of the superimposed AC ripple to the DC voltage level was chosen to be 10% and 20%, respectively. The results show that the AC ripple led to increased accumulation of space charge within the sample. The higher ratio of ripple voltage resulted in greater amount of space charge accumulated in the sample.