Comparative optimization design of an interior permanent magnet synchronous motor for an automotive active steering system

This paper presents the comparative optimization design of an interior permanent magnet synchronous motor (IPMSM) for an automotive active steering system. This application requires a high performance motor with a high torque/volume (mass) ratio, low inertia, high dynamics, good field weakening and high temperature capability. The proposed solution is the result of an optimization design process, which considered the whole range of performance, technology and costs aspects. Two different design approaches are presented: a classical (experience-based) design method and an optimization design method using three different optimization algorithms (Hooke-Jeeves, genetic algorithms, and grid-search). The evaluation of the fitness function for the multiobjective optimization was performed using an analytical model with embedded finite element (FE) correction factors. The solutions of the two design methods are compared. Design details and experimental results for a prototype are also presented.