Multicell-to-Multicell Equalizer With Hybrid Pulsewidth Modulation and Phase-Shift Modulation
Guo Xu, Enze Chen, Fulin Liu, Yonglu Liu, Wenjing Xiong, Mei Su
Abstract
In this article, an any-cells-to-any-cells equalizer based on the multiwinding transformer is proposed to reduce the component number and increase the balancing speed. Every two adjacent cells only require two <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s and one transformer winding to construct a buck–boost converter, and several two-cell groups construct a multiactive bridge converter, which achieves a low component number. By modulating the duty cycle and phase-shift ratio, the equalization between different cells can occur simultaneously, which achieves fast balancing speed. In addition, a current distribution strategy is designed in detail, which ensures that the balancing current of each cell is under modulation during the equalization process. Finally, a prototype, including six lithium-ion cells, is established. The experimental and comparative results verify the correctness of the theoretical analysis.