The Motor Selection

Liping Zheng

University of Central FloridaUniversity of Central Florida

Motor Specifications

Must have high reliability. Efficiency is most important, volume and weight are also

important.

Speed 50Krpm

Power output 100KW

Efficiency >94%

Alternative Motor Types (I)

Permanent Magnet Synchronous Motor (PMSM) Has high power density and high efficiency. Can obtain high efficiency due to no copper loss

associated with motor excitation. Requires rotor position measurement for high

efficiency operation.Brushless DC Motor (BLDC) Also has high power density and no copper loss

associated with motor excitation. Has high iron loss at high speed comparing with

PMSM.

Alternative Motor Types (II)Wound-Field Synchronous Motor High power application. Not good for speed higher

than 25krpm because of rotating windings, slip rings, and brushes.

Switched Reluctance Motor (SRM) Provides fault tolerance. Has high losses and low

efficiency at high speed.Induction Motor (IM) Low cost alternative to PMSM. Larger in size than

PM motor but close to PMSM in efficiency. Asynchronous motor, need speed control.

Motors available

Turbocor PMSM with magnetic bearing 140hp (104kW) @ 48KrpmElectrodynamics associates inc. Induction motor. Under development. 200kw @ 62Krpm (160kw @ 50Krpm) Efficiency >95%.