Optimal Design Of Ferrite-assisted Synchronous Reluctance Motor Based On Multi-physics Filed Analysis

The assisted synchronous reluctance motor is interposed between permanent magnet synchronous motor and synchronous reluctance motor.The permanent magnet materials of permanent magnet synchronous motors are generally Nd Fe B and ferrite.Nd Fe B motors have problems such as high cost,high speed overpressure and high temperature demagnetization.Ferrite motors are relatively more advantageous,and they can use reluctance torque and permanent magnet torque to improve power density and efficiency,so they are highly concerned by scholars.Therefore,the research object of this paper is a ferrite-assisted synchronous reluctance motor,which is optimized based on genetic algorithm and Taguchi method,and then performs electromagnetic-temperature multiphysics coupling analysis.Firstly,the structural characteristics and mathematical models of SynRM and Fa-SynRM are compared firstly.The principle of equivalent magnetic circuit method is introduced.The Fa-SynRM physical model is established and the equivalent magnetoresistance expression of dq axis of motor is obtained.Secondly,the influence of the air gap length and the width of the four layer insulating barrier on the performance of the motor is analyzed.The torque ripple is used as the optimized goal.The Taguchi method is used to obtain the parameter range of the parameter.Then the orthogonal structure is used to design the rotor structure.The mean and variance are analyzed to obtain the optimized parameter values to determine the final design model of SynRM.Thirdly,the ferrite material is inserted into the optimized SynRM rotor magnetic barrier to obtain the Fa-SynRM model.With the power factor as the main optimized goal,the genetic algorithm is used to roughly optimize the parameters globally,and then the Taguchi method and the finite element method are combined.Partially and carefully optimize the parameters,reduce the torque ripple and ferrite volume while improving the power factor.At the same time,the optimization of the length and width of the ferrite and the verification of the air gap length ensure the accuracy of the optimization process,and analyze the influence of the split ratio coefficient on the performance of the motor,fully improve the power factor of the motor.The electromagnetic characteristics under no-load and load were studied,and the rationality of the Fa-SynRM optimization design was further verified.Finally,the finite element analysis software of electromagnetic field is used to calculate the no-load and load,rotor iron loss and copper loss and mechanical loss of the winding.At the same time,the thermal conductivity and heat dissipation coefficient of the motor material are calculated.The temperature of each part of the motor is obtained by electromagnetic-temperature multiphysics coupling analysis.The influence of air gap length on the overall temperature rise of the motor is studied.The final Fa-SynRM design model is determined.