该文在分析我国井下高压电网短路故障的基础上,深入研究相关保护原理及提高井下高压电网保护灵敏度和可靠性的方法,设计出新型的井下高压短阶梯延时选择性过流保护方案,从而做到快速的、有选择性的切断故障线路,避免煤矿井下高压电网因越级跳闸而造成大面积停电。 Based on the analysis of short-circuit faults in China’s underground HV power grid, this paper deeply studies the relevant protection principle and the method to improve the sensitivity and reliability of underground high-voltage power grid protection, and designs a new scheme of selective overcurrent protection for short-time high-voltage short- Fast, selective cut off the fault line to avoid large-scale blackout due to the over-voltage trip of high-voltage grid in coal mines.