A Numerical Analysis of Accumulated Surface Charge on DC Epoxy Rrsin Spaces

The insulation strength of solid dielectric spacers, sand wiched between electrodes and stressed by dc voltage, can be influenced by surface charges building up during voltage application. The measurement of these trapped charges is diffi cult during the charge accumulation process, but may be car ried out by means of well-defined probes while interrupting the voltage application. The field can be calculated numerical ly, starting from the trapped charge and employing suitable boundary conditions during voltage application. A comparison with measured quantities can contribute to an explanation of the physical charging mechanism. The surface charge simulation method which was used in this analysis is quite obviously an essential tool for the treatment of this and related problems.