Research on X-ray Detection of Internal Discharge and Mechanism Defects in GIS

Internal discharge and mechanism defects are common defects in gas insulated switchgear (GIS) equipment. Here, X-ray digital radiography technology was used to detect defects in several faulty GIS equipment in power grid. Firstly, the X-ray detection results showed that metal debris were found in the faulty circuit breaker compartment. Through inspection of the equipment compartment, it was confirmed that there were a large amount of metal erosion, discharge dust, metal slag, etc. inside, indicating the occurrence of multi position discharge. Then, X ray was used to detect that the distance between the moving and static contacts of the faulty circuit breaker had increased. After opening the compartment for inspection, it was found that the bolts between the fixing mechanism and the chassis were loose. Subsequently, the position of the moving and static contacts of a faulty GIS equipment isolation switches was detected, and it was found that the moving contacts exceeded the shielding cover when in the opening position. Finally, X-ray was first used to inspect the mechanism side guide ring of the circuit breaker, and it was found that the guide ring was loose. This work further validates the efficiency and accuracy of X-ray detection for discharge defects and active mechanism defects in GIS equipment. (Abstract)