Performance and Comparison of Cell Balance Techniques for EV Application

Abstract

The long life cycle, high in energy densuity and low in self-discharging rate made liathium-ion batteries popular  ​ However, when multiple cells are connected in series, inconsistencies in internal resistance, capacity, and self-discharge rates arise due to manufacturing and environmental factors. These inconsistencies can lead to overcharging or over-discharging of individual cells, reducing battery capacity, shortening lifespan, and posing safety risks. Balancing methods are essential to address these issues. Existing methods are categorized into: Dissipative balancing: Converts excess energy into heat, leading to energy loss. Non-dissipative balancing: Transfers energy between cells using capacitors, inductors, or transformers, offering higher efficiency. ​ A bidirectional flyback converter topology with multiple winding input/output is suggested in the paper to get over the drawbacks of current techniques