基于多端故障行波时差的含分布式电源配电网故障定位新方法

A Novel Multi-terminal Fault Location Method Based on Traveling Wave Time Difference for Radial Distribution Systems With Distributed Generators

分布式电源（distributed generator,DG）接入配电网会改变配电网的拓扑结构和潮流方向,大量电力电子设备接入,传统的故障定位方案可能失败。为有效解决含分布式电源配电网的故障定位问题,将成功应用在输电网的行波定位技术应用于配电网,有望实现配电网快速、准确故障定位。首先,该文阐述了DG接入,电力电子设备及其控制系统对初始行波波头传输特性的影响,分析了配电网行波信号与输电网行波信号的差异,论证了含分布式电源配电网进行故障行波定位的可行性。其次,利用双端定位原理和多端初始行波到达时刻,搭建故障支路搜索矩阵,根据矩阵元素变化特征判定故障支路,进而计算出精确故障点位置。最后,首次在实验室搭建了10k V故障行波动模试验定位平台。PSCAD/EMTDC仿真分析和动模试验测试表明：该文方法可以快速、准确定位故障点位置,且不受故障点参数的影响,具有良好的适应性,定位绝对误差为100m。

Distributed generator（DG） gird-in will change the topology structure of distribution network and the direction of power flow, meanwhile a large amount of electric power and electronic equipment grid-in will cause traditional fault location scheme failure. In order to effectively solve the fault location problem in distribution network with DG grid-in, fault location technology based on traveling wave, which has been successfully used in transmission network, will be used in distribution network. It is hopefully to realize speedy and accuracy fault location. Firstly, the influences of traveling wave characteristics caused by power electronic equipment and its control system are analyzed, meanwhile the differences of traveling wave signal between distribution network and transmission network was clearly analyzed. On the basis, the feasibility of fault location method based on traveling wave used in distribution network with DG grid-in was verified in this paper. Secondly, based on double-terminal fault location method, fault branch searching matrix was set up by using multi-terminal initial traveling wave arrival times. The variation rules of elements in the matrix can judge the fault branch, and further the accuracy fault point can be located. Finally, a 10 k V fault location dynamic simulation testing platform based on traveling wave was firstly built in the lab. PSCAD simulation and dynamic simulation testing resultsshow that the proposed method is with fast-speed and accuracy, and immune to the parameters at fault point. The absolute fault error is within 100 m.