红外热成像技术在金属氧化物避雷器缺陷检测中的应用

Application of Infrared Thermal Imaging Technology in Metal Oxide Arrestor Defect Detect

在对某500 k V变电站红外测温巡查时发现2号主变压器500 k V侧金属氧化物避雷器V相温度偏高,随即对该组避雷器进行运行中持续电流检测、1 m A直流电流条件下电压U1m A检测、0.75倍U1m A条件下泄漏电流测量,试验数据超标,推断该避雷器电阻片故障。将避雷器返厂进行拆解、试验,发现故障原因为内部受潮,局部闪络,导致绝缘电阻下降。实例证明了红外热成像技术能快速、有效地发现该类故障,是诊断金属氧化物避雷器故障的有效手段之一。

In some 500 kV substation, the infrared temperature detect that V-phase metal oxide arrester（MOA） of the No.2 main transformer in the side of 500 kV was in over temperature, then took measuring test of persistent current detection, the voltage of U^mA under 1 mA DC current and leakage current under 75%UaImA. The test data was exceeded, by which further verified the arrester resistance fault. Then back to factory for the dismantling and experiment, discovered the cause of failure was internal moisture, local flashover, resulting in insulation resistance drop. And proved that the infrared thermal imaging technology could quickly and effectively discover such an accident, and it was an effective method in diagnosis of metal oxide arrester malfunction.