Disturbed PD Detection System Based on Improved φ-OTDR Assisted by wFBG Array

A disturbed acoustic sensing system (DAS) based on improved φ-OTDR is proposed and experimentally demonstrated. A weak fiber Bragg grating (wFBG) array is introduced into sensing fiber to increase the signal to noise ratio (SNR) of system. In order to detecting the acoustic signals generated by partial discharge (PD) of 10KV power cables, the sensing fiber was packaged with an aluminium tape to enhance the sensitivity. The experimental results demonstrate that the system performs well in demodulating PD signals, and has advantages of relatively high sensitivity and broadband frequency response.