Distributed Detection and Acoustic Emission Waveform Retrieval of Cable Joint Partial Discharge

Distributed detection and acoustic emission (AE) waveform retrieval of partial discharge (PD) in power cable joints are significant but challenging tasks. In this article, we proposed a cable joint PD detection method based on optical fiber distributed acoustic sensing (DAS). Ordinary single-mode optical fiber (SMF) was wound on the outer semiconductive layer to obtain sufficient sensitivity. Coherent optical time domain reflection (COTDR) principle was utilized to detect the phase variation and locate the PDs. The AE waveforms were retrieved by Fourier integration and difference operation. The experimental results indicated that the sensing system had the ability of multi-point monitoring. The PD AE waveforms caused by conductor spike and insulation air gap defects were accurately retrieved.