Assessment of a Multilevel Converter for a PHEV charge and traction application

With the Plug in Hybrid Electric Vehicle (PHEV) the introduction of a charger has to be done. A standalone onboard charger will increase both weight and cost of the vehicle. A better option is the integration of the charging function into the already existing propulsion converter. The aim of this paper is to assess the multilevel converter as an integrated vehicle charge and propulsion converter. A comparison between conventional converter technology and multilevel converter technology is made both on component level and system level. The investigation, based on calculations, simulations and measurements, points to some features that can; increase the efficiency of the total system; increase the life time of the energy storage; and increase the utilization of the energy storage. However, the investigation also points to features that can increase the cost and complexity of the system and reduce efficiency in certain operation points.