组“发变组TA断线”信号报警分析

#6 Unit"Transformation Group TA Disconnection"Signal Alarm Analysis

黄埔电厂#6机组报“发变组TA断线”信号,短时报警后消失,通过录波文件和对硫26B、#6发电机、#6主变,18 kV封母进行了电气绝缘、耐压等相关试验分析排除发电机内部发生接地故障的可能。停机检查发现在硫26B变压器本体高压侧A相靠近引出线处上方电缆线槽松脱且有一根电缆已断,初步判断为变压器线圈A相测温元件电缆受外力作用在硫26B变压器引出线上来回摆动触碰而引发的“发变组TA断线”信号报警。

Unit#6 reported the signal of“TA disconnection in the transformer group”,and disappeared after a short-term alarm.Through the recording file and the sulphur 26B,#6 generator,#6 main transformer,the 18 kV seal mother was electrically insulated and resistant.The analysis of the related tests of voltage and so on eliminates the possibility of a ground fault inside the generator.The shutdown inspection found that the cable trough above the high-voltage side of the sulfur 26B transformer body near the lead wire was loose and one of the cables was broken.It was preliminarily judged that the transformer coil A phase temperature measurement component cable was subjected to external force on the sulfur 26B transformer lead wire.The signal alarm of“transformation group TA disconnection”triggered by swinging and touching.