中文摘要：

提出一种基于三阶动态时间弯曲（DTW）算法的变压器差动保护算法。该方法利用差动保护两侧数据窗内的电流采样值构成最短距离矩阵,通过最短距离搜寻算法,在该矩阵内寻找到一条最短路径,将该路径所经过的局部最短距离元素的总距离的平均值作为两侧采样电流的差流。在数字化变电站由于通信原因造成数据延时及数据丢包的情况下,利用该差动保护算法,可使得区外故障时保护不误动作；区内故障时,保护可靠动作。仿真验证了不同延时状况及不同丢包率情况下,区内、区外故障时常规相量差动保护及DTW差动保护的动作性能。结果表明,DTW差动保护在抗延时性能、抗丢包性能及灵敏性上明显优于常规相量差动保护。

英文摘要：

A transformer differential protection algorithm is proposed based on the third-order dynamic time warping （DTW）. This method makes use of the current sample value within the bilateral data window of differential protection to constitute the shortest distance matrix.Via the shortest distance searching algorithm,a shortest path can be found in the matrix and take the average value of local shortest distance elements in the matrix through which the path passes as the differential current of bilateral sample current.Should data delay and data packet-loss happen in a digital substation for communication reasons,by using this differential protection algorithm,protection malfunction due to external faults can be avoided and protection can act reliably during internal faults.Simulation has verified the action performance of conventional phase differential protection and DTW differential protection during external or internal faults in different delay circumstances and different packet loss rates conditions.The results show that DTW differential protection has obvious advantages over conventional phase differential protection in delay-resistant,packet loss-resistant performance and sensitivity.