145 kV户外交流隔离开关触头发热原因分析

Cause Analysis on Contract Overheat of 145 kV Outdoor AC Disconnector

针对某变电站一批145 k V隔离开关触头过热更换后再次发热的故障,采用宏观检查、X射线荧光镀银层测厚、金相分析、显微硬度分析、化学成分分析等方法,结合现场运行情况,分析触头发热的原因,得出该批触头发热的原因之一是其局部存在露铜、导致接触电阻升高,露铜是镀层的硬度不足引起耐磨性差所导致,并据此提出改进建议。

Contract overheat of 145 k V disconnectors reoccurred in a substation after replacement. Macroscopic examination, X-ray fluorescence silver plating layer thickness testing, metallographic analysis, microhardness analysis, chemical composition analysis methods are used to analysis the reasons by combining field operation. It is concluded that the contract heat comes from copper exposure due to poor abrasion resistance of the layer. This paper proposes some improvements.