Absrmcl-This paper describes a surface mounted PM motor with the ratings of 5 kW and 180, OOO rpm for su r high speed drive applications such as machine tool. A much crger air gap, compared with that of the existing PIU motors, is utilized to reduce the slot ripples and hence the resultant eddy current loss In the metslllc sleeve that retains the permanent magnets, otherwise this loss would be objectionable at such high speeds. The motor is supplied from a quasi-current source inverter with the dc current controlled by a chopper and operated at a near unit power factor by the use of a simple position sensorless control, to Improve the motor efficiency. The analytic results are presented to show the slot ripple reducing effect of increasing the air gap lengtb. To investigate the losses of the sleeve, several motors with different sleeve were manufactured and tested. 5pical experimental results on these prototypes are given, which show that motor efficiency of higher than 90% can be realized at the rated torque over a wide speed range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.