Comparative Analysis of Cell Balancing Techniques and Development of Active Cell Balancing Model Using Inductor

From last few years there is increase in the demand of electric vehicle, and battery is one of the important element of EV's [1]. As the Lithium-ion battery is one of the critical element and it can create cell imbalances inside the battery pack. The main reasons behind cell imbalances are aging effect, manufacturing defects, external atmospheric conditions. Due to these causes the internal resistance of lithium- ion cell will increase result in cell imbalances. These imbalances are in the range of 3-6%. There are basic two ways to balance all the cells in a Lithium-ion battery pack and that are Passive balancing and active balancing. In the passive balancing technique the extra energy from overcharge cell is dissipated in the form of heat through resistor in order to balance the cells where in active balancing energy transfer will take place from overcharge cell to undercharge cells through energy storing elements. This paper presents a cell balancing mechanism using a multiple inductor topology. The main advantage of this topology over capacitive balancing is high rate of balancing. Inductor based balancing is one of the simplest but effective way of balancing. This paper provides a practical approach of active balancing along with comparative analysis of different cell balancing topologies.