摘 要 煤矿井下供电系统受井下巷道延伸方向的限制，在同一方向上存在多级供电开关，井下供电电缆线路阻抗较小，各级开关短路电流值相差很小，保护难以整定，因此井下供电保护系统存在动作不灵敏、可靠性差、参数难以调整的缺点，致使矿井供电线路保护易发生误动作和越级跳闸，造成井下大面积停电的恶性事故。 本文论述国内外防短路故障越级跳闸技术的发展现状基础上，指出目前短路故障保护系统在国内煤矿使用中存在的问题；分析目前主流防越级跳闸系统的技术原理，比较不同技术的优缺点和适用范围；根据孟村煤矿井下供电系统概况和实际需求，考虑井下变电所的设置及井下供电系统主接线结构，分析孟村煤矿井下各级变电所短路电流数值接近的原因及井下供电系统发生越级跳闸的技术原因，为设计防越级跳闸系统给予理论支撑。选择电流速断区域闭锁原理解决孟村煤矿井下越级跳闸问题，对井下各变电所分别进行了防越级跳闸系统硬件配置、选型设计，制定了系统的闭锁逻辑，所运用的新技术、新方法是井下供电系统安全运行的技术保障；设计了检验防越级跳闸系统可靠性的试验方式，并通过试验证实了论文所采用方案的可靠性。分析孟村煤矿井下供电系统防越级跳闸系统的应用前景，并指出防越级跳闸系统未来的研究方向。 通过上述理论分析与论证，可靠解决了孟村煤矿井下供电系统存在的安全隐患，为孟村煤矿井下供电系统的安全运行提供了可靠保障。

ABSTRACT The coal mine underground power supply system is limited by the extension direction of the underground roadway. There are multi-level power supply switches in the same direction. The impedance of the underground power supply cable is small. The short-circuit current values ​​of the switches are small, and the protection is difficult to set. Therefore, the underground power supply protection system exists. The disadvantages of insensitivity, poor reliability, and difficulty in adjusting parameters make the mine line protection prone to malfunctions and over-the-counter trips, resulting in a vicious accident of large-scale underground power outages. This paper discusses the development status of over-class tripping technology for short-circuit fault prevention at home and abroad, points out the problems existing in the current use of short-circuit fault protection system in domestic coal mines; analyzes the technical principle of current mainstream anti-stepping trip system, compares the advantages and disadvantages of different technologies and the scope of application Introduce the general situation of underground power supply system in Mengcun Coal Mine, mainly describe the setting of underground substation and the main wiring structure of underground power supply system; analyze the reason of the short-circuit current data of substation substation in Mengcun Coal Mine and the leap-level trip of underground power supply system For technical reasons, theoretical support is provided for the design of the anti-override trip system. The selection of current quick-break zone locking technology is used to design the underground anti-override tripping system of Mengcun Coal Mine. The hardware configuration selection design of the anti-stepping tripping system is carried out for each substation in the underground. The locking logic of the system is established. The new technology and new technology are applied. The method is the technical guarantee for the safe operation of the underground power supply system; the test method for checking the reliability of the system is designed, and the reliability of the system is confirmed by experiments. This paper analyzes the application prospects of the anti-override trip system of the underground power supply system in Mengcun Coal Mine, and points out the future research direction of the anti-override trip system. Through the above theoretical analysis and argumentation, the safety hazards existing in the underground power supply system of Mengcun Coal Mine are reliably solved, which provides a reliable guarantee for the safe operation of the underground power supply system of Mengcun Coal Mine.