OPGW Partial Discharge Monitoring Based on Distributed Fiber Optic Acoustic Sensing Technology

This research focuses on the application of the Distributed Acoustic Sensing (DAS) system in the field of partial discharge monitoring of Optical Fiber Composite Overhead Ground Wire (OPGW). The KIKUSUI AC/DC withstand voltage insulation tester is used to simulate the OPGW discharge phenomenon, and the DAS system is utilized to collect time - domain and frequency - domain signals. In view of the non - stationarity of partial discharge signals and the limitations of traditional analysis methods, an adaptive time - frequency analysis method combining the Fast Fourier Transform and the Hilbert Transform is proposed. This method can dynamically adjust the analysis window and frequency resolution. It shows high sensitivity in the partial discharge monitoring of OPGW under the voltage range of 1 kV - 5 kV, and successfully detects the high - frequency acoustic shock signal at 116 kHz, with a signal - to - noise ratio reaching 20 dB. In the case of discharge breakdown, the system can accurately capture the characteristic frequency of 115.58 kHz within 1s. This provides reliable technical support for the partial discharge monitoring of power equipment and has broad application prospects in the power system.