Breakdown in LDPE Due to Water Ingression Under DC Polarity Reversal Stress

This paper incorporates high voltage direct current step-stress and polarity reversal stress for water treeing, leading to breakdown. In this paper, water is utilized as an electrode to investigate the impact of water ingression on breakdown. A setup resembling the water treeing configuration is created, wherein a HVDC step-stress voltage is initially applied, and the corresponding breakdown voltage and characteristics are recorded. Subsequently, a DC polarity reversal voltage is applied, and breakdown is measured once again. Significantly distinct breakdown characteristics are observed between the two tests. These findings provide valuable insights into the effect of water ingression on breakdown phenomena under different stresses, contributing to a better understanding about insulation failure and will further lead to the development of more accurate models incorporating effect of polarity reversal.