An LCC Based String-to-Cell Battery Equalizer with Simplified Constant Current Control

Speaker:   Mr. Zhengqi Wei

Time:       15:30-16:30, Nov. 13

Location:  SIST 1C 101

Host:       Prof. Haoyu Wang

Abstract:

Constant current equalization can effectively mitigate the inconsistency of battery strings in a fast manner. In this manuscript, a constant current string-to-cell (S2C) battery equalizer with an open-loop control is proposed. The equalization scheme is based on LCC multi resonant topology. It utilizes a common equalizer unit shared by each unbalanced cell to transfer energy from the entire string to a single cell. A constant balancing current is achieved with simple fixed-frequency open loop control. The equalization speed is determined by the predesigned balancing current. Design considerations of the proposed equalizer are analyzed in detail, which ensure zero-voltage switching (ZVS) among all MOSFETs during the equalization process. An experimental platform to balance four Lithium- Ion battery cells is designed to verify the system performance. Experimental results validate the functionality and analysis of this equalizer. Compared with the conventional architecture, the proposed architecture exhibits a high efficiency, low components count, and obviously reduced control complexity.

Bio:

Zhengqi Wei received the B.S. degree in electronic information science and technology from Shaanxi Normal University, Xi’an, China, in 2019. He is currently working toward the M.S. degree in the School of Information Science and Technology, ShanghaiTech University, Shanghai, China, since 2019. His research interests include battery management systems and battery equalization.

SIST Student Seminar 001