Modular multilevel battery packaging for a universal and flexible EVs charging system
Electric Vehicles (EVs) carmakers are heavily confronted by the limited fault ride-through capabilities of actual EVs battery packs. Therefore, this paper introduces a new method of EVs battery packaging based on modular multilevel battery modules as well as a universal and flexible integrated charging system. This allows isolating damaged battery modules and keeping the whole system working. In addition, the concept allows charging the batteries from a wide range of charging infrastructure; from AC household basic supply to AC fast-charging as well as DC ultra-fast charging. This method consists of cascading half bridge switching cells, which are connected with battery modules in order to form a modular multilevel converter (MMC). A three phase electrical machine with slip stator windings is needed in order to use the stator winding as filtering inductance during charging mode. Moreover, the concept integrates a selecting and sorting algorithm for balancing the battery modules state of charge without using dissipative strategies.