A Multi-Source Inverter for Electric Drive Vehicles

Traditionally, energy storage systems in electric drive vehicles can be connected to the high voltage DC link through passive or active configurations. Passive configuration puts sources in parallel without any decoupling converter among sources which increases the number of series cells in battery and Ultra-Capacitor (UC) bank. Also, due to the lack of control over UC, its stored energy cannot be utilized efficiently. Active configurations exploit DC/DC converters to control the sources separately. However, existence of DC/DC converters with bulk magnetics increases the system volume and weight, and decreases the efficiency due to inductors' series resistances. Recently, multisource inverters as a new concept in electric drive vehicle applications have been introduced. Higher efficiency due to single stage conversion and compact structures due to removal of the magnetics are of the advantages of such systems. In this paper, a modular multi-source inverter is proposed for combining battery packs and UC banks as the energy storage systems in electric drive vehicles. Matlab Simulink was used for simulation purposes and a scaled down lab prototype was built to verify the simulations.