Active package to cell balancing battery management system with Isolated ĆUK converter and switch matrix

Battery Management System (BMS) is applied to battery packs to monitor the voltage, current, temperature, and State of Charge (SoC) values of each cell and provide the battery pack to operate in a safe zone. One of the battery problems is that each battery cell in the pack does not contribute energy equally to the entire pack. Li-ion batteries that are used in this paper also suffer from this problem due to their higher energy density than other batteries. Therefore, a balancing operation is needed for the voltage and SoC of each cell. In this paper, a faster active package-to-cell (P2C) balancing by using a BMS that has an isolated ĆUK converter (IĆC) and a switch matrix is proposed. The proposed BMS draws energy from the entire pack and balances the lower energized cells by converting the energy through a high-power capable IĆC and a cell-selective switch matrix (SWM) that enables the selection of one cell or up to four cells in a row. Due to the isolation, the energy can be transferred from pack to cell, and thanks to the switch matrix, it is possible to reach each cell individually. In addition, the BMS controller has a PI controller for IĆC and a cell-selective algorithm (CSA) for the switch matrix. Also, the proposed study provides a cost-effective and compact solution as compared with other P2C topologies.