柔性直流配电网单端故障定位方法

Single-ended fault location method for flexible DC distribution network

柔性直流配电网的故障定位方法能够准确定位故障,对快速排除故障具有重要意义。文中提出了一种基于电流注入技术的单端故障定位方法,当极对地故障或极对极故障发生时,故障线路将由直流断路器隔离。将定位模块放入故障线路的终端形成二阶振荡电路,利用Prony算法提取电容器放电电流的阻尼系数和特征频率。根据该故障电路的参数计算出故障距离和故障电阻。定位模块的参数设计使其特征频率保持在100Hz以下,避免了线路电感分布不均匀的影响。通过与现有方法的比较,验证了该方法的有效性和准确性。

Faults could be accurately located by faults location method of flexible DC distribution network,which is of great significance for fast troubleshooting.In this paper,a single-terminal fault location method based on current injection technology is proposed.When pole-to-ground fault or pole-to-pole fault occurs,the fault line will be isolated by DC circuit breaker.The location module is put into the terminal of the fault line to form a second-order oscillation circuit.The damping coefficient and characteristic frequency of capacitor discharge current are extracted by Prony algorithm.The fault distance and resistance are calculated according to the parameters of the fault circuit.Its characteristic is keeped frequency below 100Hz by parameter design of the positioning module,which avoids the influence of uneven distribution of inductance.The validity and accuracy of the proposed method are verified by comparison with existing methods.