Duval五边形在有载分接开关状态诊断中的应用

Application of Duval Pentagon in State Diagnosis of On⁃load Tap Changer

对比分析了Duval五边形法及Duval三角形法两种基于油中溶解气体分析的方法在鉴别有载分接开关状态方面的效果,确定了Duval五边形中与有载分接开关正常状态对应的区域,并利用Duval五边形法对特高压换流变压器有载分接开关进行实际诊断。结果表明:Duval五边形法可以实现有载分接开关正常及异常状态的辨识,超过95.5%正常状态的有载分接开关气体体积分数特征点落在编号为D_(1)的低能放电区域;对245台有载分接开关状态进行识别的结果表明,Duval五边形法对正常状态的诊断准确率高于Duval三角形法,可以作为有载分接开关状态诊断的辅助判据。

The effect of such two methods as Duval Pentagon and Duval triangle,which are based on dissolved gas analysis in oil,in identifying abnormal OLTC is compared and analyzed.The corresponding area of Duval Pentagon to the normal state of OLTC is defined and the Duval Pentagon is used for actual diagnosis of OLTC of UHV converter transformer.The results show that the Duval Pentagon can achieve normal and abnormal states identification of OLTC.The gas volume fraction characteristic point OLTC with more than 95.5%normal state fall in the low energy area num⁃bered D_(1).The identification results of 245 OLTC states show that the diagnosis accuracy of Duval Pentagon to normal state is higher than that of Duval triangle,which can be used as an auxiliary criterion for state diagnosis of the OLTC.