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.

The aim of the research project this paper arises from, is the development of a high-speed, high-efficiency generator system for use in series-hybrid vehicles. This paper describes an analytic method for the two-dimensional calculation of the magnetic field in the cylindrical air gap of the permanent-magnet generator. Further, it introduces a method to visualize this field, namely by plotting the lines of constant magnetic vector potential. To show that the calculated magnetic field may form the basis of a machine model, the voltage equations are derived. The proposed analytic method gives insight into the relations between dimensions and parameters of the machine, which is important when optimizing the design.