Research On Parametric Model And Torque Optimization Of Permanent Magnet Synchronous Reluctance Motor

Permanent Magnet-assisted Synchronous Reluctance Motor(PMASRM)has the advantages of high torque density,large salient pole ratio and wide speed regulation range,which has been widely used in the field of electric vehicles in recent years..This paper gives research on PMASRM in terms of the equivalent magnetic network analytical model,building parametric model and joint simulation platform,the rotor structure design and study of multi-objective optimization of motor performance,which provides guidance for PMASRM performance improvements.The main contents are as follows:Firstly,the analytical model based on the equivalent magnetic network model of PMASRM is given by analyzing the working principle of motor,the air gap flux density generated by permanent magnet and armature winding is calculated respectively through mathematical model.The superposition theorem is used to obtain the motor performance under the combined action which considers the impact of slot and rib saturation.In order to solve the problem of many rotor structure parameters of motor,parametric model is built.All the structural parameters are in the form of per-unit value,and joint simulation model is carried out according to the parametric model.Secondly,parametric analysis of PMASRM is carried out,and the effects of stator and rotor structures on electromagnetic performance are analyzed.Based on the built joint simulation model,the variations of q-axis inductance,d-axis inductance and permanent magnet flux linkage with motor split-ratio,the ratio of stator teeth to yoke and other rotor structural parameters are given,which verify the validity of the model.Thirdly,considering the importance of magnetic barrier structure to PMASRM,the torque performance is analyzed based on the established parametric model.Rotor structures with different layers,insulation ratios hc(p.u.),shapes and angles d?(p.u.)of magnetic barrier are analyzed to discuss the effects of various parameters on the average output torque,reluctance torque and torque ripple.The influence degree of structure parameters on the output performance of PMASRM is obtained,which provides guidance for the subsequent optimization design.Finally,the structure of PMASRM is optimized through the parametric model by joint simulation platform.The effects of different key parameters on genetic algorithm,difference algorithm and particle swarm optimization are discussed.In order to improve the traditional optimization algorithm,the multi-objective optimization difference algorithm based on noninferior hierarchical genetic algorithm is presented.The structural parameters which have great influence on the average output torque and torque ripples are obtained by the optimization results.At the same time,a suitable optimization method for different parameters is given,and the best structure of PMASRM is obtained according to the above results.