城市轨道交通大分区中压供电系统保护方案研究及应用

针对城市轨道交通大分区中压供电系统,提出一种在不同运行状态及各种故障情况下均能满足保护选择性、速动性和可靠性的完整继电保护方案。区间电缆以线路差动保护为主保护,线路电流比较保护为第二套主保护,过流保护为后备保护;母线上以母线差动保护为主保护,母线电流比较保护为后备保护。介绍进出线、母联、馈线保护和断路器失灵保护的应用,以及备自投功能的实现方式。分析大分区中压供电系统保护的配置、原理和逻辑,对区间电缆故障、母线故障、馈线故障情况下的动作行为,论证该方案对于故障点电源切除、非故障点电源恢复的性能。最后,介绍该方案在实际项目武汉地铁6号线上的应用。

Protection Scheme for Big Partition Medium Voltage Power Supply System and Its Field Application in Urban Rail Transit

For the big partition medium voltage power supply system in urban rail transit,a complete solution of relay and protection is proposed,which can meet the requirements of protection selectivity,speed and reliability under different operation conditions and various fault conditions.For the cable between two substations,the line differential protection is used as the primary main protection,the digital comparison protection of line current acts as the second main protection,and overcurrent protection is a backup protection;for the busbar,the differential protection is the main protection,and the digital comparison protection of busbar current is the backup protection.This paper introduces the application of protection for incoming and outgoing cable,bus coupler,feeder,and breaker failure,as well as the way to realize the automatic switching function of power supply.Considering the protection configuration,principle and logic,the paper makes an analysis of actions under cable fault,busbar fault and feeder fault,and demonstrates the performance of the scheme for cleating of power supply at fault point,and restoring of power supply at non fault point.At last,this paper introduces the application of this scheme in Wuhan Metro Line 6.