Direct AC charging of EV Reconfigurable Cascaded Multilevel Converter

This paper presents the Reconfigurable Cascaded Multilevel Converter (RCMC), employed for EV powertrain applications, in charging configuration. The converter is directly connected to an AC three-phase power system and the battery modules are charged by dynamically controlling the reconfigurable battery modules. The intrinsic structure of the converter gives the advantage to implement different charging algorithms, according to customizable requirements, without the need of extra middle power stages. Two charging methods are proposed and explained in detail: the first one prioritizes the SOC balancing between the battery modules, the second one the power losses reduction. Finally, a charging time estimation is computed for the RCMC and for a classic battery pack, assuming to increase their initial state of charge of 20%. The computation results show that the Reconfigurable Cascaded Multilevel Converter requires 40% less time than the battery pack.