Study on Short-Term and Long-Term Breakdown Characteristics of XLPE Cable Insulation

This article focuses on the differences in properties between Cross-linked Polyethylene (XLPE) insulation materials for high-voltage cables produced by China Wanma and Borealis. The crystallization and melting properties, cross-linking by-product content, and short-term and long-term breakdown characteristics of XLPE were tested. The results show that the 220 kV XLPE insulation produced by China Wanma has similar crystallinity, melting temperature, and cross-linking byproduct content to those produced by Borealis. The Weibull distribution analysis indicates that at temperatures of 30-50°C, XLPE insulation produced by China Wanma has higher breakdown strength compared to Borealis. However, at temperatures above 70°C, the XLPE insulation produced by Borealis shows higher breakdown strength. Furthermore, the XLPE insulation produced by Borealis demonstrates smaller dispersion in breakdown strength, indicating more stable properties. The relationship between breakdown electric field and time for the two insulation materials at 70°C is analyzed using an inverse power model. The results show that the lifespan index for the 220 kV XLPE insulation produced by China Wanma and Borealis is 19.3 and 19.5, respectively.