Transformer Complicated Sympathetic Inrush Identification With Mathematical Morphology

Differential protection has been one of the essential primary protections in the relay protections of power system transformer. In recent years, there has been some differential protection of transformer malfunction accidents, when transformer load switching nearby. Studies of domestic and foreign experts have shown that lead to such accidents mainly due to sympathetic inrush. Sympathetic inrush relative to the inrush current has a hidden. So that the method of identify inrush current may not be entirely suitable for sympathetic inrush. View of the importance of safe and stable operation of the transformer, it is necessary to study and make sympathetic inrush current identification method.In recent years, the application of mathematical morphology is more and more widely, and one-dimensional signal processing based on mathematical morphology is getting hotter and hotter. Relative to the wavelet transform theory and Fourier algorithm, all mathematical morphology operations can be operated in the time domain. Mathematical morphology, easy to implement by the hardware, can be used to complete the detection of power system transient signal distortion characteristics.The main work in this paper:1、Create sympathetic inrush current electrical model, analyze the generation mechanism of the magnetizing inrush current, study the characteristics of the theoretical analysis.2、Research the various factors which affect the inrush current by simulation of MATLAB software. Analyze the false tripping caused by sympathetic inrush current and identify the root cause of the inrush current generated malfunction.3、Program the transformer sympathetic inrush current identification procedures, based on mathematical morphology, with MATLAB. Use this procedure to identify the transformer differential current and draw criterion of identifying the sympathetic inrush.