基于特征暂态零模电流偏态系数的有源配电网单相故障定位方法

含分布式电源的配电网是新型电力系统的重要组成部分，但分布式电源接入导致配电网的故障形态变得复杂，特别是使得中性点经消弧线圈接地的配电网单相故障特征进一步被弱化，配电网单相故障定位变得愈加困难。现有方法存在灵敏度不足或特征量提取与处理困难的问题，通过解析有源配电网单相故障暂态过程中零模电流的分布特点，发现故障点上游和非故障区段的暂态零模电流始终呈振荡衰减且极性相反的特征。进而引入偏态系数刻画暂态零模电流的振荡衰减特征，构造了基于特征暂态零模电流偏态系数的单相故障定位判据，并提出了有源配电网单相故障区段的灵敏定位方法。理论分析和仿真结果表明，该方法在显著降低故障特征量提取及处理难度的基础上，仍能可靠实现有源配电网单相故障区段定位，具有整定计算简单和抗通信干扰能力强等优点，为新一代配电网单相故障快速定位提供理论依据。

Single-phase fault location method for an active distribution network based on the skewnesscoefficient of characteristic transient zero-mode current

A distribution network with distributed generation is an important component of the new power system. However, the access of distributed generation leads to complex fault patterns. In particular, the single-phase fault characteristics are further weakened under the neutral via arc suppression coil grounded system, resulting in the serious difficulty of single-phase fault location. To address the problems of insufficient sensitivity or difficulty in extracting and processing the characteristics posed by existing methods, the zero-mode current and its distribution characteristics in the transient process of a single-phase fault in the active distribution network are analyzed. It is found that the transient zero-mode currents are always oscillating and decaying with opposite polarity upstream of the fault and in the non-faulted section. Then, the skewness coefficient is introduced to characterize the oscillating and decay of the transient zero-mode current. A single-phase fault location criterion based on the skewness coefficient of the characteristic transient zero-mode current is constructed, and a sensitive location method of the single-phase fault section in the active distribution network is proposed. The theoretical analysis and simulation results show that the method is able to locate single-phase faults in active distribution networks on the basis of significantly reducing the difficulty of fault feature extraction and processing. It has the advantages of simple setting calculation and strong anti-communication interference ability, providing a theoretical basis for the rapid and safe disposal of single-phase faults in the new generation of distribution networks.This work is supported by the National Natural Science Foundation of China (No. 51877018).