Factor for dielectric strength reduction due to fibrous contaminants in XLPE

We investigate the effect on breakdown strength reduction by employing several kinds of fiber, in which each effect is classified in prebreakdown by partial discharge detection and electroluminescence measurement. In the same size fiber, breakdown strength decreases in the order: solid synthetic fiber>cotton fiber>hollow synthetic fiber>copper fiber. The partial discharge behavior is clearly different between hollow fiber and copper fiber. The electrical tree characteristics are also discussed.