Practical Analysis Method of Induced Damper Bar Currents of Salient-Pole Synchronous Machines due to Stator Slot Ripple

Abstract

This paper describes a simple analysis method of induced damper bar currents of salient-pole synchronous machines due to stator slot ripple and the calculated results of the damper bar currents of a 250kW 4-poles machine.
The proposed method is based on a gap permeance model of salient-pole machines considering the peripheral variation of the gap permeance and the field mmf distribution. The damper bar currents are calculated by considering the peripheral positions of the damper bars. The validity of the proposed analysis method is shown by the good agreement with the measured currents and analyzed currents by the two dimensional electromagnetic field analysis, of the 250kW 4-poles machine. Therefore it is useful for practical damper bar designers, because of its simpleness to be used and its accuracy of the analyzed currents.