Design improvement of coupled IPM motor-drive using physics-based motor model and evolutionary approaches

In this paper, a numerical technique for the magnetic design improvement of a 6 poles-2hp-1200rpm axial flux IPM motor concerning an existing drive circuit is proposed. The design objectives are introduced as the minimum torque ripple, the minimum RMS value of phase currents, and the minimum total harmonic distortion of phase currents. These single objectives together with the current density and magnetic saturation constraints are set to be satisfied at the same time in a multi-objective function. These objectives are calculated from the simulation of the physics-based model of the machine at the same time. The physics-based model of the machine indirectly connects the magnetic characteristics of the IPM machine to the drive circuit. The physical characteristics of machine are calculated from a non-linear transient FE analysis of machine with motion. A fast convergence rate genetic-particle swarm algorithm is developed and it is used as an optimization tool. The comparisons of the calculated results before and after optimization procedures show the performance improvements as well as material savings.