A Reconfigurable Cascaded Multilevel Converter for EV Powertrain

This paper presents a new topology for EV powertrain, called Reconfigurable Cascaded Multilevel Converter, able to simultaneously implement power conversion and active battery system management. The latter feature is performed through the Reconfigurable Battery Module structure, where the serial connection of cells is controlled through a pattern of switches. This work contributes to the improvement of EV powertrain multilevel topologies by adding the advantages of reconfigurable systems. Compared to other multilevel topologies, an optimized control algorithm allows maintaining the converter efficiency comparable to more standard solutions and, concurrently, performing sorting algorithms to keep balanced SOC dynamics between the cells. Moreover, the new topology can be completely customized, according to different application requirements. To validate its feasibility in terms of efficiency, the converter is compared to other three alternative topologies. Efficiency measurements are carried out to validate the comparison. Finally, experimental results show how the active management of the battery stack can avoid voltage imbalances and be resilient to sudden voltage or load changes.