Multiphase DC/DC Converter and its Use in the Powertrain of Fuel Cell Vehicles

As part of the EU project SWARM, a fleet of fuel cell vehicles is built. In these contexts, a DC/DC converter will be developed, which will be placed between battery and fuel cell in the powertrain of these vehicles. A multiphase buck converter is selected, in order to reach the power of the fuel cell system and to reduce the filter effort. The filter circuit with different converter phase numbers is calculated. A practical realization of a six-phase buck converter is described. Measurements of phase current balancing and efficiency curves are shown. Then, a test bench is presented, in which the converter can be proven at real (driving) conditions. In this way, the best operation strategy of the converter for use in fuel cell vehicles can be found.