Comparative Analysis of Active Balancing Types for Lithium-Ion Cells

Battery Management System (BMS) of electric vehicles plays a crucial role in efficient energy management. The BMS is responsible for monitoring the voltage of each cell, the temperature of each cell, the current through each cell, and can send commands for cooling or heating systems. It determines the state of health of the cell and the state of aging. One of the most important functions of a BMS is cell balancing. Ideally, each component cell of the battery pack would have the same capacity, the same voltage, the same internal resistance, and the same rate of aging. However, this scenario is idealistic; in reality, small differences between cells arise during the manufacturing process, leading to considerable imbalances between cells. This paper aims to comparatively study the efficiency of different active balancing types that utilize either capacitors, inductors, or converters. To illustrate the differences between the various balancing methods, balancing circuits were created in MATLAB Simulink.