A Fast and Effective Optimization Procedure for the Ferrite PMaSynRM to Reduce Material Cost
Gaohong Xu, Zexin Jia, Qian Chen, Jiaqing Xia, Yangkun Cai, Zhengbing Zhang
Abstract
This article proposes a fast and effective optimization procedure to achieve a low material cost of the ferrite permanent magnet assisted synchronous reluctance machine (PMaSynRM). The key is to achieve high pole utilization first and then limit the design margin of output torque and efficiency to reduce the material cost significantly. Moreover, a rotor overhang structure reduces material costs and improves space utilization. Four optimization steps with different functions are arranged, combining nondominated sorting genetic algorithm (NSGA-II) and nonlinear programming by quadratic Lagrangian (NLPQL) searching algorithms. First, establish the optimization model and parameterize the motor model according to the design requirements. Then, the arrangement of magnetic barriers and poles is optimized to achieve high pole utilization. Next, the split ratio, tooth width, stator axial length, and current are optimized to significantly reduce the material cost while limiting the design margin of output torque and efficiency. Finally, the rotor overhang structure increases the rotor axial length while reducing the stator axial length. With the proposed procedure, the material cost of a 36-slot, 6-pole PMaSynRM is reduced from U.S. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\$}53.06$ </tex-math></inline-formula> to U.S. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\$}45.21$ </tex-math></inline-formula> while meeting performance specifications. Furthermore, a prototype has been produced and tested to verify the effectiveness of the proposed procedure.