Characteristics Analysis of Claw-Pole Alternator for Automobiles by Nonlinear Magnetic Field Decomposition for Armature Reaction

Abstract

In this study, we investigate the characteristics of claw-pole alternators for automobiles from the results of both calculation and experiments. Nonlinear 3-D finite element analysis is employed to take the claw-pole shape into account. The calculated characteristics are compared with the experimental results in order to confirm the validity of the analysis. Then, the magnetic field is decomposed according to the field sources in order to understand the effect of armature reaction. It is clarified that the large armature reaction in the claw-pole alternator causes saturation of the electrical output and an increase in the harmonic losses in the machine. The possibility of improving the characteristics by reducing the armature reaction is also clarified.