The Partial Discharge Diagnosis and Location of C-GIS Cable Joint Based on Multiple Detection Method: High Voltage and Insulation Technology

In this paper, a suspension discharge case in the cable joint of 35kV Cubicle Gas Insulated Switchgear(C-GIS) is analyzed detailedly, and the C-GIS is operated by two outlet cable. First, this paper presents the comprehensive detection process based on ultrasonic, UHF (Ultra High Frequency) and HF (High Frequency) method, and detection results show that it is helpful to approve the accuracy of partial discharge (PD) detection by using this comprehensive idea, which can play the role of mutual corroboration. Second, this paper presents the location process, which is carried out under the coordination guidance of UHFUHF location method and acoustic-UHF location method, and the defect position is located in the range between 10cm and 20cm. At last, by dismantling this C-GIS, the accuracies of detection and location results are demonstrated, and the dismantling result shows that the broken wire of charged display devices and poor bonding in stress cone, caused by plugging and pulling the cable joint repeatedly, are the fundamental reason for this PD defect.