Single-Phase Ground Fault Protection Setting Raising Method for Distribution Network Cable Lines Considering Arc Ignition Properties

With the urban distribution network renovation work, power cable lines are usually buried in underground comprehensive pipe corridors as an important means of power transmission. Currently, the urban distribution network of 10kV in China adopts small-current grounding, which can allow the system to continue to operate with faults for 1-2 hours when single-phase grounding occurs in the system. However, if ground faults are not removed in a timely manner, single-phase ground faults can occur in cables and cause fires in integrated corridors. In the article, the combustion model of power cables in the comprehensive pipeline corridor is firstly constructed on the fire simulation software FDS to analyze the effects of different working conditions in the cable compartment on the arc ignition characteristics of the cables. Find the cable ignition time corresponding to different fault currents. Then find the time of the distribution network ground fault by detecting single-phase ground faults in the distribution networks, and relate the ignition time of the cables to the time of single-phase ground faults in the distribution networks. When the fault is detected, the fault line is selected, and the trip is finally realized before the cable fire occurs, the fault is removed, and the reliability of power supply is improved.