Analysis and suppression method of transformer no-load closing excitation inrush current  

作　　者：Li Zhengming Chen Yuchen Wang Chengmin 

机构地区：[1]College of Electronic and Electrical Engineering, Shanghai University of Engineering Science, Shanghai. China

出　　处：《International English Education Research》2014年第12期97-99,共3页国际英语教育研究（英文版）

摘　　要：The primary winding of the transformer will generate large inrush current due to the saturation of iron core when an unloaded transformer is switched-on. The inrush current not only causes mechanical interaction force due to which the windings are damaged, but also induces the differential protection relays to operate incorrectly. In this paper, the mathematical model of unloaded single phase transformer in switch-on is analyzed; the computation formulas of the inrush current and its interruption angle are presented. The experiment investigation of single phase transformers with different capacities shows that the inrush current measurement result is consistent with theoretical analysis. The inrush current waveform is typically a steeple top waveform with high order harmonics and damping in one direction. In the same condition, large inrush current amplitude will be induced with smaller switching angle, larger residual flux and smaller saturation flux.

关 键 词：TRANSFORMER Magnetizing impedance Magnetizing inrush current Unload switched-on 

分 类 号：TM561.2[电气工程—电器] TM41