基于小波分析的变压器励磁涌流识别

Transformer inrush current identification based on wavelet transform

励磁涌流和内部短路电流状态的识别是变压器差动保护中的一个重要问题,通过比较励磁涌流和短路电流在物理特性上的区别,提出运用小波变换提取励磁涌流的间断角奇异性特征,实现变压器励磁涌流和短路电流的识别。仿真结果表明,该方法能够有效地提取励磁涌流的畸变特征,提高了变压器微机差动保护的准确性。

The identification of inrush current and internal short-clrcuit current is an important issue in transformer differential protection. By comparing the physical difference between excitation inrush current and short-circuit current, the identification of transformer inrush current and short-circuit current was realized by using wavelet transform to pick up singularity characteristic of inrush current dead angle. The simulation result indicated that the method could effectively pick-up the distortion characteristic of excitation inrush current and improved the accuracy of transformer microcomputer differential protection,