Abstract 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.
2020, Vol. 21 
