Multi-objective Optimization Design of Six-phase U-shaped Permanent Magnet Linear Vernier Motor

For the cordless hoisting system, a six-phase U-shaped permanent magnet linear vernier motor (SU-PMLVM) is proposed. The primary of the motor adopts a U-shaped segmented permanent magnet array, which is characterized by a high magnetization effect and a low magnetic leakage. In order to enhance the comprehensive performance of SU-PMLVM, the average thrust, thrust fluctuation, and no-load counter potential harmonic distortion rate are selected as optimization objectives. Taguchi's method is employed to expeditiously optimize SU-PMLVM in a multi-objective manner. Firstly, the optimization variables with the greatest influence on the objectives and the values of their factor levels are selected. Then, the designed orthogonal experiments are solved by using the finite element method, and the performance data of each optimization objective under different combinations of factor levels are obtained. Finally, the influence weights of the optimization variables in each optimization objective are clarified through the analysis of variance, and the optimal level combinations of the optimization variables are thus obtained. A comparison of the performance of the objectives before and after optimization indicates that the average thrust of the proposed motor has increased by 1.77%, the thrust fluctuation has been reduced by 40.06%, and the no-load reverse potential harmonic distortion rate has been reduced by 15.23%.