基于超导故障限流器的多级馈线电流保护新方案

A new current protection scheme based on a superconducting fault current limiter for a multi-stage feeder

随着配网规模的快速发展,配电网线路呈现线路短、节点多的情形,进而导致短路电流差异较小,传统电流保护方案配合困难以及故障切除时间延长。为解决上述问题,首先梳理多级馈线保护存在的问题,对多级馈线长短混联线路保护配置与整定方案进行分析,进而提出了一种基于超导故障限流器的电流保护新方案。该保护方案利用故障限流器的快速投入与限流特性实现上下游线路短路电流差异化。基于此,构建新的保护定值整定原则,缩短故障切除时间。利用PSCAD搭建多级馈线配电网模型进行仿真验证。结果表明:所提保护方案能够解决传统电流保护定值配合失效与保护动作时间过长等问题。

With the rapid development of the distribution network,the network lines show situations of short lines and many nodes.This results in a small difference of the short-circuit current,difficult cooperation of conventional current protection schemes and prolonged fault clearing time.In order to solve the above problems,first,the existing problems of multi-stage feeder protection are analyzed,and the protection configuration and setting scheme of length and short-length hybrid lines are analyzed.A new current protection scheme based on a superconducting fault current limiter for a multi-stage feeder is proposed.The protection scheme uses the fast input of a fault current limiter and current limiting characteristics to realize the differentiation of short circuit current between upstream and downstream lines.Thereby,new principles of protection setting and operation time coordination are constructed to shorten the fault clearing time.A multi-stage feeder distribution network model based on the PSCAD/EMTDC for simulation verification is built.The results show that the proposed protection scheme can solve the problems of conventional current protection setting value coordination failure and long protection action delay.