半导体纸和铝箔作为套管芯体电容极板的局部放电特性差异及分析研究

Study on the Partial Discharge Difference Characteristics between Semiconductor Paper and Aluminum Foil on Capacitor Structure of Oil-paper Insulation Bushing

套管芯体局部放电是引起套管故障的重要原因之一。传统“绝缘纸-铝箔-绝缘纸”结构为芯体的油纸绝缘套管已使用多年,为进一步优化油纸绝缘套管的芯体结构和绝缘性能,采用力学性能良好的半导体纸为电容极板,对“绝缘纸-铝箔-绝缘纸”和“绝缘纸-半导体纸-绝缘纸”两种结构体系在极不均匀电场下的工频击穿和局部放电特性开展对比研究。试验结果表明,当采用半导体纸作为电容极板时,能提高多层绝缘结构体系的起始局放电压与工频击穿电压,减少同等电压下多层结构体系的局部放电量和放电次数;相较于以铝箔作为电容极板的体系,电场分布仿真结果表明选用半导体纸的多层绝缘结构体系的电场最大值更小,有助于提升其绝缘性能。研究结果为油纸绝缘套管芯体材料的选择提供了理论参考。

The partial discharge of bushing core is one of the important causes of bushing fault.Oil-paper insulating bushing with traditional structure of“insulation paper-aluminum foil-insulation paper”as core has been used for many years.In order to further optimize the core structure and insulation performance of oil-paper insulation bushing,the power frequency breakdown voltage and partial discharge characteristics of“insulation paper-aluminum foil-insulation paper”and“insulation paper-semiconductor paper-insulation paper”are compared under extremely uneven electric field by using semiconductor paper with good mechanical properties as capacitor plate.The results show that when the semiconductor paper is used as the capacitor plate,the initial partial discharge voltage and power frequency breakdown voltage of the multilayer insulation structure system can be increased,and the partial discharge quantity and discharge times of the multilayer insulation structure system under the same voltage can be reduced;Compared with using aluminum foil as capacitor plate,the simulation results of electric field distribution show that the maximum electric field of the multilayer insulation structure system with semiconductor paper is smaller,which helps to improve its insulation performance.The results provide a theoretical reference for the selection of oil-paper insulation bushing core material.