Design of electrical high speed drives for vehicle drivetrains

In many applications, electric drives with very high power density are needed to fulfill requirements of low weight and low volume. These range from industrial and vehicle drives to aerospace applications. An increase in power can be realized by increasing the rotor speed due to the proportionality of power and speed. Higher speeds result in higher performance or smaller volumes. However, the high speed presents the engine with other challenges. The cooling of the machine becomes very important, since significantly more power loss must be dissipated in a smaller space. An important target of machine design must therefore be loss minimization and sufficient cooling concepts. In addition to strength requirements, rotor dynamic effects occur, which must be taken into account in the drive design process. In this presentation the main design rules and conception considerations for high speed drives are outlined and some data of an experimental 24.000/31.000 rpm machine just under test are given.