光纤通道异常时加速线路Ⅱ段后备保护技术

Technology of Accelerating Back-up Protection of Transmission Line ZoneⅡwith Abnormal Fiber Channel

双重化配置的输电线路光纤保护,存在因光纤通道同时异常造成线路区内故障时保护同时拒动的风险。一旦发生,将造成故障切除时间的延迟和相邻线路的无选择性跳闸,带来故障范围的扩大和电网稳定性破坏的严重后果。文中针对这种因光纤通道异常导致的线路光纤纵联保护退出情况,研究了一种自适应缩短线路Ⅱ段后备保护动作时间的技术方案,并进行了试验验证。通过加速线路Ⅱ段后备保护动作时间,达到快速切除故障同时避免相邻线路Ⅱ段后备保护无选择性跳闸的目的,提高了电网运行的稳定性和可靠性。

The dual configured transmission line protection with fiber channels has the risk of refuse operation when fiber channels are both abnormal during the internal fault.Once endangered,the fault clearing time will be delayed and the non-selective tripping of the adjacent line will occur to bring about serious consequences of enlarged fault area and destroyed power grid stability.In view of the above risky situation,an adaptive technology for shortening the time of the zone Ⅱ backup protection is proposed and verified by experiment.The technology makes it possible to achieve rapid tripping time while avoiding non-selective tripping of zone Ⅱ backup protection of the adjacent line by accelerating the zone Ⅱback-up protection. It can also improve the stability and reliability of power grid operation.