Electromagnetic Performance Analysis of Claw-Pole Alternator with Changing Permeance

Abstract

A changing air gap permeance model of the alternator and its influence were discussed in this paper. When the alternator was under high-speed operation, taking it into consideration that the claws getting deformation for rotating centrifugal force and electromagnetic exciting force, the alternator’s changing air gap permeance model was established. And the alternator’s Maxwell3D calculation model was built. The field magnetic distribution under the rated speed was obtained as well, also before the claws’ deformation was obtained. The harmonics of the air-gap flux were analyzed and compared. The changing air gap permeance model was proved to be reasonable. It would lead to air-gap magnetic field distortion of the generator, which affected the generator’s electromagnetic properties. Instruction was provided for more precise of air gap magnetic field analysis or vibration noise analysis of alternator.