Optimization Design And Research Of High Reluctance Torque Multi-layer Permanent Magnet Motor

With the continuous innovation and development of modern industry,rare earth permanent magnet motors,as high-performance electromechanical energy conversion devices,play a crucial role in various fields of the national economy.In recent years,the significant price fluctuations and unstable supply chain of international rare earth permanent magnet materials have limited the large-scale development of highperformance rare earth permanent magnet motors.In order to alleviate the dependence of permanent magnet motors on heavy rare earth materials,light rare earth/rare earth permanent magnet motors represented by permanent magnet assisted synchronous reluctance motors have received widespread attention.However,due to the reduction of permanent magnet torque in permanent magnet assisted synchronous reluctance motors,their high-speed constant power zone load carrying capacity is relatively weak,resulting in high armature current and low efficiency during high-speed operation.Therefore,how to fully utilize the reluctance torque of permanent magnet assisted synchronous reluctance motors and balance the amount of permanent magnet materials with motor torque,efficiency and other requirements has become one of the difficulties and urgent problems in the design or optimization of such motors.In order to improve the overall performance of this type of permanent magnet motor,this paper proposes a high resistance torque multi-layer permanent magnet motor(HRT-MLPM motor)based on minimum d-axis flux leakage approximation,based on in-depth research on the salient pole characteristics of permanent magnet assisted synchronous reluctance motors.The mapping relationship between the torque,speed control performance,and key structural parameters of this type of motor is studied,Explore the influence of rotor structure parameters on motor performance,and carry out targeted ground motor optimization design.The main content of this article includes:Firstly,the research background and significance of the project were introduced,and the current research status of permanent magnet assisted synchronous reluctance motor rotor topology,reluctance torque improvement,torque ripple suppression,and magnetic weakening ability were elaborated in detail.The main research content of this article was also presented.Secondly,considering the operational requirements of automotive drive motors,the influence of the salient pole characteristics of multi-layer magnetic barrier permanent magnet motors on the output torque and speed control performance of the motor was analyzed in depth.On this basis,in order to achieve better speed regulation effect,a design idea is proposed to measure the speed regulation performance with the minimum d-axis flux leakage.We have carried out the design of HRT-MLPM motors,including stator slot pole coordination,basic dimensions,etc.In addition,considering the importance of rotor permanent magnet and magnetic barrier structure for the motor designed in this article,the rotor topology under different parameters is analyzed and explored,with a focus on considering the reluctance torque output and permanent magnet flux level of the corresponding model,providing guidance for subsequent optimization design.Then,taking into account the overall performance improvement needs of the motor,multi-objective optimization is carried out on the comprehensive characteristics of the HRT-MLPM motor.To balance torque and speed regulation performance,the volume ratio of reluctance torque,torque ripple,and minimum direct axis flux amplitude were all considered as optimization objectives.A comprehensive multi-objective optimization design was conducted,and the optimal motor structural parameters of HRT-MLPM were obtained through trade-off analysis.Finally,comprehensively evaluate and compare the electromagnetic performance of the HRT-MLPM motor before and after optimization,mainly including basic noload characteristics,inductance and flux characteristics,torque characteristics,anti demagnetization characteristics and loss characteristics.Processing the HRT-MLPM principle prototype and conducting relevant experimental tests,mainly including noload back electromotive force,inductance characteristics,torque characteristics,and efficiency and power experimental tests,verifying the correctness of theoretical analysis,design,and optimization methods.