Research Of Design And Torque Ripple Suppression In Unaligned Spoke-type Double-stator Permanent Magnet Synchronous Machines

In order to improve the torque density of the permanent magnet synchronous machine,reduce the torque ripple,reduce the cost of the permanent magnet material,and enhance the fault tolerance of the system.This thesis takes the Liaoning science and technology department project "Unaligned spoke-type double-stator permanent magnet synchronous machines design and fault-tolerant control research for electric vehicles"(Double-Stator Permanent Magnet Synchronous Machines: DS-PMSM)as the background,and takes the double-stator permanent magnet synchronous machine for electric vehicles as the research object.Aiming at the design problem of permanent magnet synchronous machine torque density and torque ripple and the cost of permanent magnet material,this thesis studies the design and control of permanent magnet synchronous machine with unaligned spoke type double stator structure.Firstly,the thesis establishes the mathematical model of a unaligned double-stator spoke type phase-concentrated winding permanent magnet synchronous machine,optimizing the motor parameters,analysising characteristics,deriving the expression of cogging torque,torque ripple and the calculation formula of electromagnetic torque and the calculation model of each part of inductance,which lays a foundation for simulation analysis and optimization design of motor characteristics.Secondly,based on the multiphysics condition designs the unaligned double-stator spoke type phase-concentrated winding permanent magnet synchronous machine.Based on the mathematical model and characteristic analysis of the unaligned double-stator spoke-type permanent magnet synchronous machine,the design flow is determined,considering the mutual influence of the output characteristics of the machine,electromagnetic field and torque ripple,designs the electromagnetic and mechanical structure of the machine.The thesis proposes a double-arc and ferrite permanent magnet block spoke arrangement to effectively improve the torque density and compactness of the structure.The method is designed to reduce the cogging torque of the machine and reduce the torque ripple of the machine by designing the internal and external stator teeth offset by an electrical angle of 90°.Then,it sets up the finite element model of the unaligned double-stator spoke-type permanent magnet synchronous machine and calculates the parameters of the machine.With the aim of minimizing torque ripple and maximizing torque output determins the electromagnetic structure size and parameters.This thesis gives the magnetic density,the back electromotive force,the cogging torque waveform and designs the mechanical structure.Based on the harmonic injection method reasearches the control method of the unaligned double-stator spoke-type permanent magnet synchronous machine with torque ripple suppression function,it establishes the simulation model of the control system of this kind of machine,and compares the ripple of the speed and torque before and after signal injection.Finally,built the machine and the system experimental platform to complete the related experiments of the double-stator machine back electromotive force and cogging torque to verify the correctness of the proposed scheme...