Cable Fault Detection and Location System Based on Low Background Noise Distributed Acoustic Sensing

When a cable fault occurs, timely fault location is essential for quickly restoring power supply. Traditional methods such as the bridge method, pulse reflection method, and impact discharge acoustic measurement method suffer from limitations like short detection distances and low positioning accuracy. Compared with conventional cable fault detection and location techniques, Distributed Acoustic Sensing (DAS) systems offer advantages such as precise positioning, high sensitivity, and long-distance monitoring. However, previous studies on cable partial discharge detection using DAS typically rely on sensitivity-enhancing devices or multiple loops of bare fiber to improve system sensitivity by increasing the efficiency and length of acoustic interaction with the optical fiber. In practical applications, these sensitivity-enhancing devices and multiple loops of bare fiber significantly complicate construction and are prone to damage. This study demonstrates experimentally that using an ultra-low self-noise, low-repetition-rate DAS system can effectively detect discharge signals from cable faults without the need for sensitivity-enhancing devices or multiple loops of bare fiber, provided the optical cable is straightened. This significantly improves the feasibility of DAS for practical cable fault detection and location.