Research on the Diagnostics and Simulation of High Voltage XLPE Cable Terminal Defects

Ultra high frequency (UHF) and high frequency (HF) current partial discharge (PD) detection technology can detect PD phenomenon caused by internal defects of transformers, gas-insulated switchgear (GIS) and cable terminals and avoid insulation failure of the electrical equipment. Meanwhile, the Medical CT Imaging Technology provides reliable precise and intuitive measures for detecting human internal disease. Based on several real cases, this article raises the method to detect PD signal, diagnose and locate defects under the successful application of UHF, HF and Medical CT Imaging Technology in detecting and positioning internal gap defects of 110kv cable terminals and GIS. It also calculates PD distortion caused by internal gap defects using the Finite Field Simulation. All simulation results, field testing consequences, and the assembling of equipment with defects verify this method of diagnosis and detection efficient and scientific.