Active Charge Equalization of an ‘m×n’ Battery Stack in Electric Vehicles during Charging, Discharging, or Isolated Condition

In this paper, an active battery charge equalization technique for Electric Vehicles using an ‘m×n’ battery stack is proposed and analyzed. The proposed configuration allows to achieve voltage and current balance of all the batteries in the battery stack during charging, discharging, or idle situations. A fourth-order battery integrated dc-dc bi-directional converter with a battery stack is operated to implement charging, discharging, and isolated conditions for the battery stack. The whole equalization process as well as an analysis of the effect of duty ratios on equalization time and equalization current of the battery stack is explained. The obtained results were found to be consistent with the theoretical analysis.