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.
作者
周志昊
Zhou Zhihao(State Grid Jibei Electric Power Co.,Ltd,Langfang Power Supply Company,Langfang,Hebei 065000)
出处
《电气技术》
2020年第6期69-72,共4页
Electrical Engineering
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
transformer
DC magnetic bias
excitation current
wavelet transform
DC component
distortion time
