Development of Modular BMS Topology with Active Cell Balancing

This paper presents the design, implementation and experimental validation of a modular battery management system (BMS) featuring active cell balancing. The proposed BMS consists of a master module and multiple slave submodules responsible for monitoring and balancing 22 cells connected in series. The master module collects voltage and temperature data from the slave submodules and measures the battery current to estimate the cells’ state of charge (SoC). Each slave module performs cell voltage and temperature measurements and controls a balancing circuit based on dc-dc converters. This work describes in detail the development and validation of the dc-dc converter based in the switched inductor topology, presenting the converter’s operational principles, a theoretical and simulation-based analysis of its performance, the implementation of the MOSFETs driver circuits based on PNP transistors and experimental results obtained from a submodule prototype. The results demonstrate the capability of the switched inductor converter to achieve effective voltage equalization by transferring energy from the cells with higher voltages to cells with lower voltages.