Document Type




Format of Original

9 p.

Publication Date



Institute of Electrical and Electronics Engineers (IEEE)

Source Publication

IEEE Transactions on Industry Applications

Source ISSN



In this paper, a multiobjective design optimization method combining design-of-experiments techniques and differential-evolution algorithms is presented. The method was implemented and utilized in order to provide practical engineering insights for the optimal design of interior and spoke-type permanent-magnet machines. Two combinations with 12 slots and 8 poles and 12 slots and 10 poles, respectively, have been studied in conjunction with rare-earth neodymium-iron-boron (NdFeB) and ferrites. As part of the optimization process, a computationally efficient finite-element electromagnetic analysis was employed for estimating the performance of thousands of candidate designs. Three optimization objectives were concurrently considered for minimum total material cost, power losses, and torque ripple, respectively. Independent variables were considered for both the stator and rotor geometries. A discussion based on a systematic comparison is included, showing, among other things and despite common misconception, that comparable cost versus loss Paretos can be achieved with any of the rotor topologies studied.


Accepted version. IEEE Transactions on Industry Applications, Vol. 51, No. 4 (July-August 2015): 2940-2948. DOI. © 2015 Institute of Electrical and Electronics Engineers (IEEE). Used with permission.