一起油浸式套管介损超标缺陷分析及运维措施

Analysis of an Over-standard Dielectric Loss Defect of Oil Immersed Bushing and Operation & Maintenance Measures

对一起500 kV油浸式套管介损异常增长缺陷进行分析。通过分析该套管的油化、电气试验数据和电容芯卷绕、装配记录,认为该套管电容芯子卷绕过程存在工艺问题,由此导致套管内部在高电场作用下发生局部放电,长期局部放电造成油中溶解气体超标和介质损耗缓慢增长。套管解体检查结果验证了分析的正确性,最后从运维角度提出了有效预控措施。

An abnormal increasing dielectric loss defect of 500 kV oil immersed bushing is analyzed.By analyzing the oil chemistry and electric test data of the bushing and the winding and assembling record of capacitor core,it is considered that there are processing problems in the winding process of capacitor core,which led to the partial discharge inside the bushing under the action of high electric field and the long term partial discharge led to the over-standard of dissolved gas in oil and slowly increasing of dielectric loss.The disassembling inspection results of the bushing testified that the analysis is correct.Finally,the effective preventive measures are proposed from the perspective of operation and maintenance.