Short-Term and Long-Term Breakdown Chracteristics of XLPE Insulation High-Voltage AC Cable at Home and Abroad
In order to explore the performance difference of XLPE insulation materials for high-voltage cables at home and abroad,220 kV domestic and imported cable insulation slice samples are prepared,and the molecular weight,melting and crystallization characteristics,cross-linking by-product content,short-time breakdown characteristics and long-time breakdown characteristics of the two insulation materials are compared.The experimental results show that the molecular structure,crystallinity,melting temperature and by-product content of domestic 220 kV XLPE cable insulation are not significantly different from those of imported insulation materials.The Weibull distribution characteristics of short breakdown field strength of two kinds of insulation materials are analyzed.It is found that the breakdown field strength of domestic XLPE insulation materials is higher than that of imported insula-tion materials at 30～50℃,while when the temperature exceeds 70℃,the breakdown field strength of domestic XLPE insulation materials decreases significantly and is lower than that of imported insulation materials,and the dispersion of breakdown field strength of domestic XLPE insulation materials is higher.The breakdown times of two kinds of insulating materials under five electric fields at 70℃are analyzed.The direct relationship between breakdown electric field and time is analyzed by using the inverse power model,and the results show that the life indexes of domestic and imported 220 kV insulating materials are 19.3 and 19.5 respectively.The research results provide theoretical and experimental support for the development and application of domestic XLPE insulation.
万方数据
维普
