Analysis of Excitation Current in DC-Biased Transformer by Wavelet Transform

作者：Zhou Xuesong^*; Zhou Zhihao; Ma Youjie; Wu Dongfang

来源：Przeglad Elektrotechniczny, 2012, 88(5B): 108-112.

• transformer
• DC magnetic bias
• excitation current
• wavelet transform
• energy spectrogram

To analyze the excitation current in DC-Biased Transformer in depth, the thesis deduces the mathematical expression of distortion excitation current, and put forwards 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, we resolve its wavelet LF approximation signal and HF detail signal, conclude DC component size of the distortion excitation current, 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. Through analyzing the energy spectrogram in the signal high-frequency band of distortion excitation current and short circuit current are determined. Simulation results show that energy changes in the high frequency band among the different scale. In practice, DC bias can lead to the action of relay protection device, which does harm to the system potentially.

• 出版日期2012
• 单位天津理工大学