A Fast Finite Element Model Taking Into Account 3-D Effects for the Optimal Design of Micro-Hybrid Starters

This paper presents a fast design method taking into account 3-D effects in a reinforced brushed dc motor used as starter in automotive application. Because of their low cost and simplicity, reinforced starters are used in micro-hybrid vehicles. The specific geometry of such devices induces an axial component of the flux which cannot be accounted for by 2-D models. 3-D finite element (FE) models are suitable for this purpose but their excessive need of CPU time complicates their use in an automatic optimization procedure. We propose to identify the overhang effects by using an adapted and corrected 2.5-D FE model which is validated by 3-D computations and experiments. Finally, the 2.5-D model is implemented in a multiobjective optimization procedure.