A Wireless Power Feedback-Based Battery Equalizer With Multiple-Receiver

Active balancing methods for battery systems in electric vehicles (EVs), utilizing wireless power transfer (WPT), have attracted considerable attention due to their noncontact operation, compactness, and safety. However, conventional WPT-based balancing methods primarily function during the charging process while neglecting the discharging operation. To address this issue, a wireless power feedback multiple-receiver (WPF-MRx) topology with a corresponding battery balancing method based on a buck converter is presented in this article. In this topology, power is discharged from a series-connected battery pack to the load via the buck converter, wherein the inductor of the buck converter serves as the transmitting coil. In addition, each battery cell is equipped with a corresponding receiving coil, capturing the feedback energy from the transmitting coil. To achieve active balancing, an auto-dormant wireless balancing algorithm is presented in this article by adjusting the shunt current of each battery cell, thereby minimizing power losses, and accelerating the balancing process. Comprehensive evaluation and validation of the presented system are derived from a proof-of-concept experimental prototype.