Development and Application of 10 kV Pole-mounted Switch Moisture Defect Detection Device

In recent years, pole-mounted switch failures have occurred frequently. Disassembly analysis of fault cases shows that internal moisture caused by aging and failure of equipment seals is the direct cause. However, existing detection methods are unable to effectively identify the internal moisture state of pole-mounted switches. To address this issue, this paper has developed a 10 kV pole-mounted switch moisture defect detection device based on the leakage current and high-frequency pulse signals generated by internal moisture in pole-mounted switches. The device comprises two components: hardware and software. The hardware system collects leakage current and high-frequency pulse signals flowing through the grounding wire of the pole-mounted switch via high-precision sensors. These signals undergo filtering, amplification, and analog-to-digital conversion through a signal conditioning circuit, providing data for software analysis. The software system integrates data processing, feature extraction, and result visualization functionalities. It can display signal characteristic waveforms in real time and perform fusion recognition on high-frequency pulse current and leakage current signals based on the Dempster-Shafer evidence theory. This enables the determination of the internal moisture degree of the pole-mounted switch, thereby achieving intuitive presentation and accurate evaluation of the equipment's insulation status. Experimental verification demonstrates that this device can effectively detect internal moisture ingress defects in live pillar-mounted switches, providing a scientific basis for condition-based maintenance of distribution networks.