Heavy vehicle drive using electric machine with permanent magnets - has excitation magnetic poles of different permanent magnetic materials for obtaining high coercive forces

摘要

The tractive electric machines are of the external or internal pole type. The excitation magnet poles are made of different permanent magnetic materials. Thus mostly highly coercive materials are arranged and/or enriched, with defined properties on pole zones exposed to heavy demagnitising. For the remaining pole zones, exposed to lower or move demagnetising, materials of highly remanent components are preferably used. Thus, particularly in connection with soft magnetic shunt materials, a highest possible useful flux is attained but at quasi-stationary and dynamic loads, possibly with additional electric excitation and/or magnetic flux blocking. In addition, a considerable resistance to permanent demagnetising is obtained, particularly with heavy duty machines and/or overload conditions, while retaining the best possible spatial flux density distribution.