少稀土非对称永磁电机的分层多目标优化分析

针对传统稀土永磁电机稀土材料用量高、永磁磁场不易调节问题，本文提出了一种少稀土非对称混合永磁电机，采用两种不同永磁材料励磁以降低稀土永磁材料的用量，混合永磁材料的非对称放置结构设计以改善电机的电感性能，提升电机弱磁升速性能。针对该电机相对复杂的结构，提出基于参数敏感度的分层多目标优化设计。对电机进行了参数化建模，建立包含转矩、转矩脉动、反凸极比和铁耗的多优化目标函数。通过参数敏感度分析对众多尺寸参数进行分层筛选，针对主敏感参数采取多目标遗传算法优化，而次敏感参数则采用响应面与多目标自适应优化结合的方法确定电机最优的尺寸参数，并对电机优化前后的电磁性能进行了分析比较，验证了优化方法的可行性，为该类复杂结构电机性能的改善提供了更加丰富的优化设计方法。

Layered Multi-objective Optimization Design Analysis of Less-rare-earth Asymmetric Hybrid-magnet Motor

Aiming at the problems of high rare earth material consumption and difficult adjustment of permanent magnetic field in traditional rare-earth permanent magnet motors,this paper proposed a less-rare-earth asymmetric hybrid-magnet motor.Two different permanent magnet materials were used for excitation to reduce the consumption of rare earth permanent magnet materials.The asymmetric placement structure of the hybrid-magnet materials was designed to improve the inductance performance and enhance the flux-weakening performances.Aiming at the complex structure of the motor,a hierarchical multi-objective optimization design based on parameter sensitivity was proposed.The parametric model was built and a multi-optimization objective function including torque,torque ripple,anti-salient pole ratio and coreloss was established.Through parameter sensitivity analysis,a plurality of dimensional parameters were hierarchically screened.The main sensitive parameters were optimized by multi-objective genetic algorithm,while the sub-sensitive parameters were optimized by response surface and multi-objective adaptive optimization.The electromagnetic properties were analyzed and compared,which verified the feasibility of the proposed optimization design method and provided a richer optimization design method for improving the performance of the motor with complex structure.