Generation Characteristics of White Powder on the Buffer Layer of XLPE High Voltage Cable

High-voltage XLPE cables often experience water blocking buffer layer breakdown failures, one of the characteristics is the appearance of white powder on the buffer layer. Breakdown often occurs at the location of the powder. Currently the reason for the generation of the white powder is unknown. To avoid the occurrence of similar failures, it is necessary to study the generation characteristics and mechanism of the white powder. This paper conducts a quantitative analysis of the generation characteristics of white powder under the influence of electric field, pressure, and moisture factors, based on which the generation mechanism of the powder is analyzed. The results show that when moisture is 2 mL, the generation rate of white powder is the fastest. When the pressure on the buffer layer varies from 998.2 N/m
²
to 9982 N/m
²
, the generation rate of white powder shows a trend of first increasing, then decreasing, and finally saturating. Pressure and moisture are necessary conditions for the generation of white powder, while electric field accelerates its generation process. The main component of white powder is aluminum oxide, which is generated by chemical and electrochemical corrosion of aluminum, carbon black, sodium polyacrylate, water, and other substances.