一种利用相似度函数来识别励磁涌流的方法

提出了一种基于波形相似度的区别励磁涌流和内部故障电流的方法。由于谐波和非周期分量的存在,磁通和励磁电流的非线性,导致了涌流波形是一个非正弦波形,而内部故障电流基本上是由基频分量组成的正弦波。根据两者波形的差异,定义了两种相似度评估函数,分别从波形的长度和方向上对采样波形及其基频波形进行综合评估,相似度高的被认为是故障电流,相似度低的被认为是励磁涌流。数字仿真和动模试验的结果证明了该方法的有效性和灵敏性。

A New Method to Identify the Inrush Current Based on the Similarity Estimation

A novel scheme based on the similarity estimation proposed,for distinguishing between transformer magnetizing inrush current and inner fault current.The transformer fault current is mainly sinusoidal waveform.However,the inrush current is featured by no periodic and dead angle,so it is not sinusoidal.It may possible to make use of this different.This paper proposes two similarity functions,by which give an estimation of the waveform in term of length and direction.If the similarity is high,then the current ...