Modelling of saturation and cross-saturation effects in an interior PM automotive alternator

Abstract

A rare-earth 6kW interior PM machine has been examined as a concept demonstrator for a high power automotive alternator. This machine has a high magnet flux density resulting in strong cross-saturation, and operates with high stator currents resulting in heavy saturation. It is desired to improve the machine design to reduce both saturation effects and hence increase the output power, particularly at low speeds. This paper examines the effect of saturation and cross-saturation on the output power, and uses finite-element analysis to model the machine flux-linkage curves. The finite-element results were verified against the experimental results.