Efficiency and cost-effectiveness of AC drives for electric vehicles improved by a novel, boost DC-DC conversion structure

On the basis of a comparative approach, the design analysis of 3/spl phi/VSI is reviewed, pointing-out the drawbacks of battery voltage variations on IGBT and capacitor bank sizing. Boost converters would compensate for such drawbacks, however a comparative analysis justifies why the common single-leg boost is to be avoided and how two-phase or H-Bridge converters can do the job, outlining design properties of multiphase conversion structures. A novel inductive coupling reactor is presented to improve further the design of boost-supplied AC drive, showing possible overall benefits by comparative analysis. These are confirmed by prototype realization. Particular concern is dedicated to loss measurements techniques, due to the very high efficiency of the prototype converter.