AC and DC Charging for Electric Vehicles with a Battery Modular Multilevel Management (BM3) Converter System

Inhalt:
This paper introduces an approach of AC and DC charging for electric vehicles that use a Battery Modular Multilevel Converter System instead of a conventional permanently interconnected battery pack. It includes five additional switches into the system that are operated depending on the pins connected at the charging port of the vehicle for charging. The electric motor’s strand windings are used as a filter to reduce the distortions introduced by the converter’s switching operation. It is shown by simulations that the concept works for all four of the charging modes intended for electric vehicle charging. In contrast to conventional vehicles, battery cell balancing can be achieved already during the charging process and DC charging at multiple different voltage levels is possible. Furthermore, a dedicated on-board charger can be omitted.