电容式电压互感器故障实例及分析

Example and Analysis of Malfunction of the Capacitive Voltage Transformer

通过对电气设备绝缘进行介质损耗与电容量测量,可以发现设备绝缘缺陷,但对于电容式电压互感器与耦合电容器等绝缘结构的设备,在进行绝缘诊断时,应更重视电容量的变化。结合电容式电压互感器的故障实例,理论分析了试验结果出现介质损耗变化不大而电容量变化明显的原因,并提出应加强在线电容量测试,实时监测绝缘运行状态。

The insulation defects can be found through dielectric loss test and capacitance measurements of electrical equipment, but for capacitive voltage transformer （CVT） and coupling capacitor, the change in capacitance should be paid greater attention in the time of insulation diagnosis. Based on the faults of CVT, this paper theoretically analyzes the reasons why dielectric loss changes a little while capacitance changes a lot, and proposes some measures to strengthen online capacitance testing and monitor the real-time status of insulation.