Detection and analysis of internal abnormal heating for high voltage switchgear based on infrared thermometric technology

There are many reason for the abnormal heating in switchgear such as the insulation defect, insulation aging, poor contact of conductive loop and so on, so the infrared temperature measurement of switchgear is important for the evaluation of switchgear operation status. The structure and composition of KYN28-12 and XGN-40.5 switchgear are introduced, and analyzed the abnormal heating type for switchgear. The abnormal heating of internal contact connector, post insulator, cable parachute skirt, puncture cabinet casing, current transformer and switchgear are researched combined with the field experience of infrared thermal imaging testing. The reason of abnormal heating are analyzed and put forward the treatment scheme by using the surface temperature judgment, relative temperature difference method and similar comparison judgment method. It is shown that the position of internal abnormal heating is different with the different types of switchgear. The surface temperature judgment and similar comparison judgment method are employed in the heating of equipment caused by current. The relative temperature difference method is used in the heating of equipment caused by voltage. It can provide a practical application basis for condition based maintenance and technical guarantee for the actual field detection.