一起气体绝缘式电流互感器放电现象分析

Discharge Phenomenon Analysis of Gas Insulated Current Transformer

SF6气体绝缘电流互感器以其结构简单、绝缘性能良好等优势在电力系统中得以广泛应用,是电网保护及测量的主要设备,分析电流互感器的故障成因对维护电网安全意义重大。论文针对一起500 kV SF6电流互感器绝缘击穿现象展开研究,分析该型电流互感器结构,建立介质模型,进行电场计算,对比使用自制外套、Axicom外套以及国内其他结构流变工作电场强度,并分析故障成因,最终得出本次SF6电流互感器放电现象是由于流变内部绝缘裕度不合理造成,为同类型气体缘式电流互感器的设计优化、故障诊断和运行维护提供参考。

SF6 gas insulated current transformer is widely used in power system thanks to its simple structure and perfect insulation performance and is the main equipment for protection and measurement of power grid.It is of great significance to analyze the fault causes of current transformer for maintaining power grid security.In this paper,the insulation breakdown phenomenon of a 500 kV SF6 current transformer is studied,the structure of the current transformer is analyzed,the dielectric model is established and the electric field is calculated.The rheological electric field strength of self-made coat,Axicom coat and other domestic structures are comparedand the fault causes are analyzed.Finally,it is concluded that the discharge of SF6 current transformer is due to unreasonable rheologic al intern al insulation margin,which can provide reference for design optimization,fault diagnosis and operation maintenance of the same type of gas insulated current transformer.