Two Stage Module Based Buck-Boost Converter for Cell Equalization of Series Connected Cells for Electric Vehicle Battery Pack Applications

In this paper, a two-stage module-based active cell balancing circuit using a buck-boost converter is proposed. In this technique cell balancing is performed by considering the State of Charge as a balancing criteria. Further to explore modified buck-boost converter topology with inductor and switches being used for balancing adjacent cells. An existing work of two stage module based cell equalization topology is referred. Such topology is aimed at increasing balancing speed by targeting two cells simultaneously. The topology uses fewer components than traditional balancing circuit. Proposed cell balancing is simulated by MATLAB/Simulink. The efficiency and time required for balancing is evaluated. An SOC based control is proposed instead of voltage based control in the proposed topology. Further the efficacy of such circuit in dynamic condition i.e. charging and discharging is evaluated through simulation.