Design And Optimization Of High Performance Permanent Magnet Assisted Synchronous Reluctance Machine

The PMA-Syn RM with ferrite permanent magnet material has the advantages of high efficiency,low cost and wide range of speed regulation,which has received extensive attention from experts and scholars all over the world.However,because the deficiency of large torque ripple,low average torque and low power factor,the application of PMA-Syn RM in emerging areas such as new energy vehicles is restricted.There are many challenges in multi-objective optimal design of the motor,because the uncertainty of PMA-Syn RM caused by the complicated multi-layer flux barrier rotor structure and the machining error.In addition,the calculation time increases when the finite element model is used to operate the accurate calculation.Thence,in order to improve the performance and robustness of PMA-Syn RM,and decreasing the calculation time,the paper focuses on PMA-Syn RM rotor structure design and robust multi-objective optimization research,The research has both theoretical significance and engineering application value.First,based on the 3k W,4-pole PMA-Syn RM,the PMA-Syn RM topology structure with high-torque performance was researched,and the PMA-Syn RM structure with 4 poles,36 slots and three layers of flux barriers was determined by comparing the torque performance of different pole slots,and different rotor flux barrier layers.Then,the amount of permanent magnets was determined based on the study of the impact of permanent magnets on motor performance,and the topology of permanent magnets replace in two wings of the flux barrier was adopted to increase the average torque of the motor,and the asymmetric structure of the flux barrier to reduce the motor torque ripple.In order to achieve the improvement of PMA-Syn RM permanent magnet torque and reluctance torque utilization together,the PMA-Syn RM with asymmetric rotor structure is proposed.Then,the motor structure is simplified to reduce the motor design variables,and the average torque,torque ripple and power factor are set as the target function,and the weight of the impact of each motor design variable on the target performance were analyzed through the taguchi method,determining the motor optimization variables and optimizer space.And then,multi-objective optimization of sequence subspace based on DE algorithm and Pareto evaluation are carried out for each subspace,aiming to achieve the overall improvement of PMA-Syn RM electromagnetic performance.Considering the PMA-Syn RM multi-objective optimization has long design period and the impact of uncertainty on motor performance,the robust multi-objective optimization design of PMA-Syn RM based on response surface model was carried out.The research scheme is to characterize the uncertainty of motor optimization variables through motor machining errors and normal distribution,and then the PMA-Syn RM response surface model is established to complete deterministic multi-objective optimization,and select the scheme which meet the requirements on the Pareto frontier solution,and calculate the robustness of the scheme.The research goal of simultaneously improving the performance and robustness of PMA-Syn RM are achieved,and the optimization efficiency is improved.