重载铁路牵引变电所电流增量保护动作分析

Analysis of actions of current increment protection in traction substation of heavy-haul railway

近年来重载铁路采用交流机车后,牵引变电所电流增量保护动作次数逐渐增加。为此,从电流增量保护的原理入手,着重从跳闸和故障录波等数据以及线路条件、机车运行等多个方面,分析了电流增量保护动作的原因,确认造成电流增量保护误动作是保护设计和定值取值存在缺陷,并通过计算找到了采用电抗法测距原理的故标装置在电流增量保护跳闸后所测出的故障距离不能作为查找真实故障点的依据;最后就变电所保护定值、变电所故障测距和保护的闭锁措施等几方面存在的问题给出了相应的改进措施。

In recent years,with the adoption of AC locomotive in heavy-haul railway,the number of actions of incremental current protection in traction substation increases gradually.Therefore,this paper starts with the principle of current incremental protection,analyzes the reasons of current incremental protection action from tripping,fault location,fault wave recording,the train line conditions,locomotive operation and other aspects.It is confirmed that the“misoperation”of current increment protection is caused by the defect of protection design and fixed value.Through calculation,it is found that the fault distance measured after the current increment protection tripping cannot be used as the basis to find the real fault point.Finally,the corresponding improvement measures are given for the problems existing in the substation protection fixed value,fault location and protection blocking measures.