Battery Modular Multilevel Management (BM3) Converter applied at Battery Cell Level for Electric Vehicles and Energy Storages

This paper introduces a modular battery system based on an integrated 3-switch inverter topology, referred to as Battery Modular Multilevel Management (BM3) system. The 3-switch topology can be directly applied on battery cell level. In interconnection with the other battery cells, series and parallel connections can be flexibly formed across the battery modules to synthesize any kind of output voltage. In this manner the BM3 topology can work as a flexible DC/AC or DC/DC converter. Furthermore, individual cells can be bypassed, so that each cell can be charged and drained according to their individual capacity. Thus, any additional passive or active balancing circuitry becomes obsolete. Within the frame of this paper’s analysis, the basic functionality of the BM3 topology is explained and the possible application as a DC/AC inverter is validated using a small scale prototype setup.