Modularized Equalization Architecture With Transformer-Based Integrating Voltage Equalizer for the Series-Connected Battery Pack in Electric Bicycles
Bin Xu, Lizhou Liu, Zhaotian Yan, Zhuqing Yuan, Lu Zhang, Wei Zhou, Ruikun Mai, Zhengyou He, Yongpan Liu, Huazhong Yang
Abstract
Due to the electrical isolation, fewer switches, and easy control, the transformer-based integrated equalizer is promising in commercial applications. However, few balance energy transmission channels limit the transformer-based integrated equalizer applied to the long battery string. Therefore, a integrated voltage equalizer with a modularized architecture (MEA-TE) is proposed. The proposed equalizer increases the energy transmission channels, which realizes the balance for the long battery string. The modularized equalizer consists of three parts: the dc–dc converter, the converter-to-module transformer (CMT), and the module-to-cell transformers (MCT). The <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> in the dc–dc converter drives the CMT, and the CMT drives all the MCTs to balance each cell. The proposed MEA-TE equalizer only uses one <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> to balance the large battery pack. The MEA-TE platform for eight battery cells is established. The results demonstrate that the MEA-TE equalizer can realize the balance of the large battery pack.