基于动态时间弯曲距离的主动配电网馈线差动保护

基于馈线上不安装电压互感器、馈线终端(FTU)通信实时性较差和时间同步能力较弱的工程应用背景,提出一种主动配电网馈线差动保护方法。利用相电流突变量启动算法,触发馈线区段边界上各FTU相互交换1个工频周波的故障电流采样数据,再通过计算各FTU故障电流的动态时间弯曲(DTW)距离确定是否为区段内部故障。该保护在启动算法与抗同步误差能力强的DTW算法的配合下,不需要获取电压信息,不要求FTU间准确同步,对数据通信实时性要求不高,数据运算量小,对FTU硬件配置要求低,适用于分布式电源高度渗透的含多分支线路的主动配电网。仿真结果说明了所提方法的有效性。

Feeder Differential Protection Based on Dynamic Time Warping Distance in Active Distribution Network

This paper proposes a novel feeder differential protection method for active distribution network. The protection is especially suitable for such feeders where voltage transformers are not equipped or both real-time communication and time synchronization ability of feeder terminal units (FTU) are weak. Firstly, the fault starting algorithm based on phase current fault component is used to trigger FTUs on the boundary of feeder section. And then these FTUs interchange fault current sampling data of a power frequency cycle. At last, dynamic time warping (DTW) distance of the sampling data is calculated to judge whether the section is faulty. With the cooperation of fault starting algorithm and DTW algorithm which has strong ability to resist synchronization error, neither voltage transformer nor precise synchronization among FTUs is necessary. This protection is easy to implement with low requirements of real time communication and computing capacity. It is also suitable for active distribution network with multi branch lines and high penetration of distributed generation. Simulation results verify the feasibility of the proposed scheme.