An algorithm for distinguishing internal fault current from magnetizing inrush current of power transformer based on wavelet transform
The distinguishing internal fault current from magnetizing inrush current of power transformer is still the main duty of the current differential protection of power transformer. This paper researches on an algorithm for distinguishing internal fault current from magnetizing inrush current of power transformer based on wavelet transform. First the reason of emerge magnetizing inrush currents is presented. Then the characteristics of magnetizing inrush currents and internal fault currents are presented. It introduces some principle for distinguishing internal faults current from magnetizing inrush current of power transformer and their limitation: the second harmonic restrains technique, intermittence angle method and wave shape symmetric theory. At the same time, it proposes a new algorithm for distinguishing internal faults current from magnetizing inrush current of power transformer based on the theory of wavelet transform. There are not only the advantages of simplicity and convenience, but also the advantages, due to considering the relationship the differences between magnetizing inrush currents and internal fault currents more deeply in nature. The simulation results indicate the algorithm could effectively distinguishing the characteristics of magnetizing inrush current from internal faults current based MATLAB, it improves the accuracy of transformer differential protection based on microcomputer.
transformer differential protection magnetizing inrush current fault current wavelet transform
YANG Long NING Jingdong LI Donghui ZHAO Zhijie
School of Computer and Information Engineering, Harbin University of Commerce, Harbin 150028, China
国际会议
第八届国际测试技术研讨会(8th International Symposium on Test and Measurement)
重庆
英文
724-727
2009-08-01（万方平台首次上网日期，不代表论文的发表时间）