ABSTRACT
An electric machine is an electromechanical device used for energy conversion fromelectricaltomechanicalandviceversa.Inavehiclesystem,theelectric machinecanbedesignedtoprocesssuppliedenergyanddeliverpoweror torquetothetransaxleforpropulsion.Themachinealsoprocessesthepower ¨owinthereversedirectionduringregenerationwhenthevehicleisbraking converting mechanical energy from the wheels into electrical energy. The termmotorisusedfortheelectricmachinewhenenergyisconvertedfrom electricaltomechanical,andthetermgeneratorisusedwhenpower¨owis intheoppositedirectionwiththemachineconvertingmechanicalenergy intoelectricalenergy.Thebrakingmodeinelectricmachinesisreferred to as regenerative braking. There are electrical, mechanical, and magnetic lossesduringtheenergyconversionprocessineitherdirectioninanelectric machine,whichaffecttheconversionef‹ciency.Someenergyisalwayslost fromthesystemforanyenergyconversionprocess.However,theconversion ef‹ciencyofelectricmachinesistypicallyquitehighcomparedtothatof other types of energy conversion devices.
