一种配网地下电缆故障定位新方法

A New Fault Location Method for Underground Cables in Distribution Networks

随着能源需求的增加,目前城市中地下电缆的使用不断增多。提出一种配网系统中地下电缆故障定位的新方法,该方法仅利用单端量测信息就可实现故障定位。首先分析了地下电缆的结构,确定了电缆各项物理参数的计算公式;然后以A相芯-护套-地故障为例,利用继电保护装置端量测的电压、电流数据,计算故障点电压和故障点电流,并将计算方法推广至芯-护套和芯-地故障。最后利用PSCAD EMTP进行仿真,对比了在不同故障阻抗、故障类型、接地方式等情况下本文故障定位方法的误差,说明了本文所提方法的有效性和适应性。

With the increase of energy demand, the use of underground cable in cities is increasing, and the fault location of underground cables has become a tough issue nowadays. This paper presents a new method for fault location of underground cable in distribution network system. Using this method, only single terminal measurements in the relaying systems is needed. Firstly, the structure of underground cable is analyzed, and the calculating formula for every physical parameter of cable is determined. Then, taking A-phase core- sheath-ground as an example, the fault point voltage and fault point current can be calculated with the voltage and current data measured by the relay protection device end, and the calculation method is extended to the core-sheath and core-ground fault . Finally, PSCAD EMTP is used for simulation, and the error of the fault localization method in this paper is compared under different fault impedance, fault type and ground mode, etc., indicating the effectiveness and adaptability of the method proposed in this paper.