Detection and Localization of Partial Discharge Based on Flexible Piezoelectric Thin Film Material

In order to detect the acoustic emission signal produced by partial discharge of SF6 gas-insulated transformer (GIT), a high sensitivity acoustic detector based on a new type of flexible piezoelectric sensor has been developed. The acoustic-solid coupling model of partial discharge of a gas isolation cell has been constructed using COMSOL Multiphysics software. The volume and power of detector has been reduced by optimum design. A low-power partial discharge fault location system including sound detection and digital signal processing circuits has been constructed. Faults of different types of defect has been simulated and test. The test result shows the intensity of sound waves generated by faults is approximately proportional to the flashover breakdown voltage and the acoustic signals generated by insulation faults are mainly in the low frequency range of 5-20 kHz.