Eddy-current losses in the permanent magnets of a PM machine

A gas turbine driven, high-speed, high-efficiency generator system intended for use in series-hybrid vehicles is developed. It consists of a permanent-magnet (PM) generator and a rectifier. The eddy-current loss in the magnets of the high-speed PM generator may be problematic. Therefore, a model of the PM machine including this loss in the magnets due to the time harmonics of the stator currents is introduced and verified. This loss can be represented by magnet loss resistances in the equivalent circuits. It can be decreased by using smaller magnets or by using sinusoidal stator currents.