非正常回路中感应电流引起电容式电压互感器发热的研究

Research on Overheating of Capacitive Voltage Transformer Caused by Induced Current in Abnormal Circuit

电容式电压互感器对遥测、继电保护等二次设备的正常运行和电网的安全稳定起着重要作用,运行中的电容式电压互感器如出现异常情况,应立即查明原因并及时处理,这要基于有效的故障检测、诊断和处理技术。根据一起带电检测发现的110kV电容式电压互感器家族性缺陷,给出了缺陷现象、查找过程和最终处理措施,并从理论上分析了此家族性缺陷形成的原因,锁定了具体的发热点,确定了缺陷是由厂家安装工艺不合格造成的,理清了此类缺陷的排查和处理方法。最后,结合日常巡视、红外测温、电气试验及工作经验,对运行电容式电压互感器的故障诊断和运行维护提出了建议。

The capacitive voltage transformer(CVT)is significant for the normal operation of secondary electrical equipment and reliable power systems,so it is necessary to identify the cause and maintenance timely if the running CVTs have unusual situations,which depends on effective techniques of fault detection,fault diagnosis and fault maintenance.Based on the familial fault of a 110 kV CVT which has been detected recently,the fault phenomenon,diagnosis process and final handling measures are provided,the formation reasons of the familial fault are theoretically analyzed,and then the specific heat spot is locked out.It is determined that the cause is failure of factory installation process,thus the investigating and handling methods of the similar fault are sorted out.Finally,combined with routine inspections,infrared temperature measurement,electrical test and work experiences,the references and suggestions for fault diagnosis,operation and maintenance of CVT are proposed.