Analytical prediction of armature-reaction field in disc-type permanent magnet generators

A two dimensional (2D) analytical method to predict the armature-reaction f ield in the slotted opening airgap/magnet region of a permanent magnet (PM) disc-type generator is presented. The currents in the slot is modeled by a uniform distributed current sheet along an are at the slot opening. The an alysis takes into account the harmonics in the armature current waveforms w hich are calculated from the voltage equations. The effects of the stator s lot openings are being accounted for by the introduction of a 2D relative p ermeance function which is calculated directly from the nonlinear equation described,by conformal transformation. A more refined permeance distributio n can then be obtained easily.