BEGA-a biaxial excitation Generator for automobiles: comprehensive characterization and test results

This paper presents the design and test results for a biaxial excitation generator/motor for automobiles (BEGA), which has a three-phase stator and a salient-pole excited heteropolar rotor with multiple flux barriers filled with low-cost permanent magnets (PMs). For this new generator, the low-voltage regulation is obtained by the flux-barrier PM combination with field (excitation) low-power control and a full-power diode rectifier in the stator. Good power/volume and superior efficiency (up to 80%) are obtained at costs comparable to those of an existing Lundell generator. The generator configuration, principle, equations, finite-element field analysis, design optimization, performance characteristics, and test results, together with the generating system simulations, constitute the core of the paper.