Mechanism and Monitoring and Early Warning System of Power Cable Burning Caused by Ground Fault

Studying the mechanism of power cable burning caused by ground fault: the grounding fault current flows through the cable phase shield for a long time, and the current density is too high, causing it to heat and melt the cable insulation material, and thermally decompose flammable gas, which is ignited by the arc at the single-phase grounding fault point. The heating process of power cables under ground fault conditions was studied and a heat accumulation model was established. Combined with the power cable safe operation specifications, the light warning value was determined with the goal of ensuring the service life of the power cable, and the heavy warning value was determined with the goal of ensuring that the fire accident of the power cable does not occur due to ground faults. A power cable burning monitoring and early warning system for a 10 kV distribution network consisting of more than 300 monitoring points was established.