抄録
HDPE has excellent insulating properties under DC voltage in sheet sample, since its breakdown strength is high and the space charge accumulation is small. However, thickness dependence of DC breakdown strength was observed in HDPE cable, which was considered to be caused by the increase of voids with the increase in cable wall thickness. DC breakdown seems not to occur due to void discharge deterioration. It was considered that the void discharge in HDPE cable insulation where the space charges are accumulated under high DC stress, induces electron avalanche and lead to breakdown.
