应对不确定性短路电流超标的保护柔性跳闸策略  

Flexible Tripping Strategy Dealing with Uncertain Excessive Short-circuit Current

作　　者：马啸 刘畅[1] 陈乐[1] 魏繁荣[1] 汪致洵 王子璇 林湘宁[1] 李正天[1] MA Xiao;LIU Chang;CHEN Le;WEI Fanrong;WANG Zhixun;WANG Zixuan;LIN Xiangning;LI Zhengtian(State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,Hubei Province,China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学)

出　　处：《中国电机工程学报》2019年第19期5782-5792,共11页Proceedings of the CSEE

基　　金：国家自然科学基金面上项目(51577077);国家电网公司科技项目(5100-201999331A-0-0-00)~~

摘　　要：针对电力系统中存在的不确定性短路电流超标问题,提出一种保护柔性跳闸策略。首先,利用基于递推最小二乘原理的短路电流预测算法,在超高速保护动作之前获得初步的短路电流预测结果,以此判断保护出口直接启动断路器分闸是否存在超标风险。在监测到保护出口标志变为"跳闸"状态后,刷新短路电流预测结果,对首次超标判断的结论进行校核,并在规定时间内搜寻可行分闸区间,进而确定保护的重新开放时刻,实现超标断路器的安全开断。最后,基于PSCAD/MATLAB,模拟500kV输电系统的短路电流超标场景。仿真结果表明,所提保护柔性跳闸策略在短路电流超标50%的严重故障场景下,依然可以有效规避强行开断超标断路器的风险。Aiming at the problem of uncertain excessive short-circuit current in power system, a flexible tripping strategy was proposed in this paper. Firstly, a fault current prediction algorithm based on the recursive least square principle was used to obtain the preliminary short-circuit current prediction result before the operation of ultra-highspeed protection, so as to determine whether there is a risk of exceeding the interrupting capacity when the protection tripping signal directly starts the circuit breaker’s opening. After monitoring that the protection operation sign becomes "tripping", the prediction of short-circuit current was refreshed, by which the result of the first judgment was checked. Meanwhile, the feasible opening interval was searched within the given time, calculating the unblocking time of the protection to realize the safe-opening of the over-limit circuit breaker. Finally, based on PSCAD/MATLAB platform, the excessive short-circuit current scenes of 500 kV transmission system were simulated. The simulation results show that the proposed flexible tripping strategy can effectively avoid the risk of forced-opening of the over-limit circuit breaker even in the extremely severe fault scene where the short-circuit current exceeds 50% of the interrupting capacity.

关 键 词：不确定性短路电流超标 柔性跳闸策略 短路电流预测 可行分闸区间 超标断路器 

分 类 号：TM77[电气工程—电力系统及自动化]