基于物元理论的电容式电压互感器故障诊断方法

A fault diagnosis method for capacitance voltage transformers based on matter element theory

目前主要通过电容式电压互感器(capacitance type voltage transformer,CVT)二次电压和红外测温数据发现运行CVT状态异常,而具体故障类型通过停电试验和解剖确定,检修试验工作缺乏针对性,效率低。停电前对CVT故障类型进行诊断,可提高停电后故障处理针对性和效率。基于此以CVT末屏电流变化率、二次电压变化率和电磁单元温度差为特征,建立CVT高压电容击穿、中压电容击穿、电磁单元故障三种典型故障的物元模型。通过计算待评CVT与典型故障模型的关联度对待评CVT的故障类型进行诊断。经实例分析验证该诊断方法可对故障CVT的故障类型做出正确诊断,提高状态异常CVT停电检修试验针对性。

Currently,abnormal operating conditions of capacitance voltage transformers(CVT)are mainly discovered through secondary voltage and infrared temperature measurement data.However,the specific fault types are determined through power outage tests and dissection,resulting in a lack of targeted maintenance and low efficiency.Diagnosing the fault types of CVT before a power outage can improve the targeting and efficiency of fault handling after the outage.Based on this,the change rate of CVT end-screen current,the change rate of secondary voltage,and the temperature difference of the electromagnetic unit are used as features to establish matter-element models for three typical faults:high-voltage capacitor breakdown,medium-voltage capacitor breakdown,and electromagnetic unit failure.The fault type of the CVT under evaluation is diagnosed by calculating the correlation degree between the CVT under evaluation and the typical fault models.Case analysis verifies that this diagnostic method can correctly diagnose the fault type of a faulty CVT,improving the targeting of outage maintenance tests for CVTs with abnormal status.