Overview of Active Balancing Methods and Simulation of Capacitor Based Active Cell Balancing for Battery Pack in EV

The increasing demand for extended range in electric vehicles has led to a surge of research focused on battery technologies. While passive cell balancing is commonly employed in electric vehicles and other applications, active balancing techniques have not been widely adopted due to their complexity and additional costs. However, there are various active balancing methods available, which can be broadly classified into intelligent switching and pulse width modulation approaches. In this paper, we explore the use of non-intelligent switching techniques for capacitor-based active cell balancing, which can help simplify the complexity of the balancing process. We specifically investigate the balancing of a twelve-cell battery pack, which can be implemented as a module within a modular battery system. Three different balancing circuit simulations were conducted: switched-capacitor balancing, double-tiered switched-capacitor, and double-tiered switched-capacitor with an additional capacitor. The simulation results demonstrated that increasing the number of capacitors in the balancing circuit led to faster balancing times. Balancing times were 1312, 1186 and 1195 seconds in this order. These findings contribute to the understanding of capacitor-based active cell balancing and provide insights into the optimization of battery pack design for electric vehicles.