Intelligent Diagnosis Method for Heating Defect of GIS Disconnecting Switch

Heating defect is one of the common defects in Gas Insulated Switchgear (GIS) equipment. Nevertheless, the detection devices and diagnostic methods for heating defect in GIS still need to be investigated. Hence, in this paper, by using the temperature test system with platinum resistance temperature sensor as sensing element and collecting the temperature of GIS internal equipment in accordance with infrared thermal image, the heating process of 110kV GIS disconnecting switch was simulated and analyzed. Then, based on the test data and thermal field simulation results, the heating defect grade of GIS disconnecting switch was determined comprehensively. As the results revealed, the internal heating defect should not be directly judged according to the shell temperature, because when the current value is small, the shell temperature change is not obvious. The heating defect inside the equipment can be inverted by the temperature of the shell, that is, the temperature of the shell can be inverted to the temperature of the conducting rod, and then the absolute temperature and relative temperature difference of conducting rod can be combined to make a comprehensive judgment of the electrical contact defect.