基于单端故障信息的配电网故障测距

Fault Location of Distribution Network Based on Single-terminal Fault Information

分布式电源(Distributed Generation,DG)分散接入使得基于传统故障特征建立的保护不再适用。为此首先利用变电站出口处采集到的线路单端电压、电流信息,将依据伏安关系求出的故障点电压与依据故障电路方程求出的故障点电压建立等式,得到关于故障距离的一元二次方程。再建立关于配网拓扑结构的修正方程,对流入故障点的电流进行修正。迭代收敛后即可得到确切的故障位置。最后在PSCAD/EMTDC上通过建模验证所提故障定位方法的有效性。仿真结果表明,该故障定位方法不受DG动作特性的约束,也不受过渡电阻的影响,适用于传统配电网以及有源配电网,且具有较高的故障测距精度。

Distributed generation(DG)decentralized access makes protection built on traditional fault characteristics no longer applicable.In this paper,it is only necessary to use the voltage and current information collected from the outlet of the substation to estabil-ish the quadratic equation about the fault distance,the left side of which is the fault point voltage abtained from the line side ac-cording to the voltage-current relationship,while the right side is the fault point voltage obtained by the fault circuit equation.Then,a modified equation for the topology of the distribution network is eastabilished to correct the fault current.After the itera-tion converges,the calculated distance and the length of feeder segment are compared to identify the fault.Finally,the effective-ness of the proposed fault location scheme is verified by PSCAD/EMTDC.The test result indicate that the proposed method is ro-bust against DG behavior and fault resistance.It’s applicable to both traditional distribution network and active distribution net-work with high location accuracy.