http://ieeexplore.ieee.org TOC Alert for Publication# 3516 2009 November 06 14 5 C1 C1 35 14 5 C2 C2 38 14 5 517 527 426 14 5 528 538 796 14 5 539 554 1719 14 5 555 563 376 MegaNdrives) are to be found in future turbo compressor systems for fuel cells and heat pumps, generators/starters for portable nanoscale gas turbines, printed circuit board drilling and machining spindles, and electric power generation from pressurized gas flow. The selection of the machine type and the challenges involved in designing a machine for megaspeed operation such as the winding concepts, a mechanical rotor design capable of 1 000 000 r/min, the selection of magnetic materials for the stator, and the optimization concerning high-frequency losses and torque density are presented. Furthermore, a review of the advantageous inverter topologies, taking into account the extremely low stator inductance and possible high-speed bearing types such as ball bearings, air bearings, foil bearings, and magnetic bearings, are given. Finally, prototypes and experimental results originating from MegaNdrive research at Swiss Federal Institute of Technology Zurich are discussed and extreme temperature operation and power microelectricalmechanical system are identified as targets for future research.]]> 14 5 564 574 794 14 5 575 589 609 14 5 590 597 643 14 5 598 605 744 14 5 606 615 700 14 5 616 625 1640 14 5 626 635 552 14 5 636 636 617 14 5 637 637 634 14 5 638 638 571 14 5 639 639 270 14 5 640 640 203 14 5 C3 C3 33 14 5 C4 C4 5