Proactive SoC Balancing Strategy for Battery Modular Multilevel Management (BM3) Converter Systems and Reconfigurable Batteries

The battery modular multilevel management converter topology and different types of reconfigurable battery topologies have been proven to be a viable option for various electric power applications. This paper presents a unique SoC balancing approach for the integrated battery strands/packs of BM3 converter systems or reconfigurable batteries. The suggested approach alternately utilizes different redundant switching state combinations to balance and to keep the battery strands’ SoCs balanced. Furthermore, the suggested algorithm attempts to utilize all converter modules, because the parallel connection of adjacent modules reduces the phase-strand’s battery impedance. Furthermore, the presented approach tries to reduce the number of switching events when changing the switching state combination. Thereby, the ohmic battery losses and switching losses are kept as low as possible. Since no power is dissipated in designated bleeder resistors and no designated active balancing circuitry is required, the suggested approach can be categorized as a proactive balancing approach. Simulations are used to verify the algorithm’s validity.