配有限流电抗器的多端直流配网故障测距方法

Fault Location Method Equipped with Current-limiting Reactor for Multi-terminal DC Distribution Network

随着直流配网的发展与分布式发电的普及,其复杂的结构拓扑与工作模态的多样性,对快速准确的故障定位提出了新的挑战。本文在研究现有直流配网故障测距方法的基础上,提出一种基于限流电抗器电压特性的多端故障测距方法。由保护安装处分别计算到故障点的电压相等得到关于故障点到保护安装处距离的方程,利用限流电抗器的电压特性求解该方程得到故障点位置。该方法较好地消除了过渡电阻和数值微分项的影响,提高了直流配网测距的精度。在PSCAD/EMTDC平台搭建多端直流配网模型,大量仿真结果证明本故障测距方法在一定的过渡电阻下可以准确动作。

With the development of DC distribution network and the popularization of distributed generations,the com-plex topology of DC distribution network and the diversity of its operating modes have posed new challenges for quickly and accurately locating faults.Based on the research of the existing fault location methods for DC distribution network,a multi-terminal fault location method based on the voltage characteristics of current-limiting reactors is proposed in this paper.Considering that the voltage values calculated from the protection installations to the fault point are equal,the equations about the distance from the protection installations to the fault point can be obtained.By using the voltage characteristics of the current-limiting reactor,the equations are solved and the fault point can be located.This method effectively eliminates the influence of transition resistance and the numerical differential term,thus improving the fault location accuracy of DC distribution network.Multi-terminal DC distribution network models are built on the PSCAD/EMTDC platform,and a large amount of simulation results prove that the proposed fault location method can accurately take actions under certain transition resistance.