Use of a permeance model to predict force harmonic components and damper winding effects in salient-pole synchronous machines

This paper presents a combined finite-element and analytical modeling technique for the prediction of force-density harmonics in salient-pole synchronous machines. The model calculates the induced currents in the damper winding cage and includes their effect on force-density components in the solution. Use of a combined analytical and finite-element approach considerably reduces simulation times compared to full time-stepping finite-element solutions, while including the effects of design changes on air-gap force harmonics. Results of the model predictions are presented together with measured data from two different machines.