The main feature of the hybrid electric vehicle (HEV) that helps to save fuel consumption is the electric motor drive. In the HEVs, there are several configurations in the propulsion systems (ex. electric motor assist or fully electric motor drive during start). The main configuration, the inverter system, is required to deliver powerful and efficient drive to the electric motor. In sophisticated electric motor drive systems, there should be a system to provide regenerative braking and transfer of energy back to the storage system via the battery charging process. The system will function as both an inverter for electric motor propulsion and converter/ generator for the battery charging process.