A Comprehensive Review of Various Topologies and Control Techniques for DC-DC Converter-Based Lithium-Ion Battery Charge Equalization

Abstract

Worldwide, electric vehicle (EV) sales are booming nowadays due to the rapid increase in the cost of fossil fuels. Lithium-ion batteries are very familiar in the EV industry because of their high energy per unit mass relative to other electric energy storage systems. To obtain the required voltage, several lithium-ion batteries are connected serially. Due to manufacturing inconsistencies, the voltage of serially connected cells is not always equal, which might result in a charge imbalance. This imbalance may reduce the battery’s life span due to the action of undercharging and overcharging. Battery charge equalisation (BCE) is challenging because it requires a constant voltage level in each cell. Various topologies and control strategies have been proposed in the past literature to build and improve the BCE. This study extracts the recently proposed DC-DC converter-based topologies for BCE. This study then gives a comparative analysis of various control strategies used in BCE and ends with implementing control strategies with BCE topology using a DC-DC converter. This study incorporates contextualised topologies used by BCE with design, operation, and applications. Extensive simulation results are provided to compare the performance of DC-DC converter-based BCE topologies in balancing speed. Also, a comprehensive comparison of various converter topologies and control strategies has been carried out for future investigation.