Multi-objective Optimizations of Copper and Aluminum Hairpin Windings: a Comparison

Abstract

This work critically analyzes the possibility of adopting aluminum hairpin windings as alternative to copper in electric traction machines for automotive applications. Copper and aluminum hairpin winding solutions are compared based on two proposed scenarios. In the first one, the same winding Joule losses are kept, whereas in the second scenario the same machine volume is maintained. In both cases, copper and aluminum solutions are independently optimized through a Multi-Objective Genetic Algorithm, with the aim of reaching the required peak torque performance, while reducing the weight and the losses in specific drive conditions. For both analyzed scenarios, the optimal designs are compared in terms of weight/volume, costs, power losses and sustainability. Finally, a hybrid layout consisting in adopting both conductor materials in the same slot is proposed, thus achieving a reasonable trade-off solution between performance and cost.