基于小波变换的电力变压器直流偏磁时励磁电流研究  

Analysis of excitation current in DC-biased transformer by wavelet transform

作　　者：周志昊 Zhou Zhihao(State Grid Jibei Electric Power Co.,Ltd,Langfang Power Supply Company,Langfang,Hebei 065000)

机构地区：[1]国网冀北电力有限公司廊坊供电公司,河北廊坊065000

出　　处：《电气技术》2020年第6期69-72,共4页Electrical Engineering

摘　　要：为了对直流偏磁条件下变压器的励磁电流做深入分析,文中推导出了发生畸变励磁电流的数学表达式,并确定了一个周期内励磁电流发生畸变的时间段。针对应用傅里叶变换分析畸变励磁电流的局限性,本文提出了采用小波变换的分析方法,通过采样不同直流电流下畸变励磁电流信号,对其进行小波低频逼近信号和高频细节信号的分解,得出了畸变励磁电流中直流分量的信息,同时确定了励磁电流波形中发生畸变的时刻,并与傅里叶变换后的结果对比分析,表明了该原理的可行性与优越性。To analyze the excitation current in DC-biased transformer in depth,the thesis deduces the mathematical expression of distortion excitation current,and determines the time slot in one cycle when the exciting current distorting happens.Meanwhile,we can put forward the analysis method with wavelet transform principle,which directs at analyzing the boundedness of distortion excitation current using the Fourier transform.Through sampling the distortion excitation current signal under different DC current,we resolve its wavelet LF approximation signal and HF detail signal,conclude DC component size of the distortion excitation current,moreover,confirm the moment of excitation current waveform distorting,comparatively analyze the results after Fourier transform,and make clear that the principle is feasibility and superiority.

关 键 词：变压器 直流偏磁 励磁电流 小波变换 直流分量 畸变时间 

分 类 号：TM41[电气工程—电器]