Research On Optimal Design Of Five-phase Permanent Magnet Machine Based On Fractional Slot Concentrated Winding

Compared with traditional three-phase machines,multi-phase permanent magnet machines have significant advantages in fault tolerance,torque density and efficiency.These features make it especially suitable for low-voltage high-power,high-performance and high-reliability applications,such as aerospace,electric vehicles and mining.This paper takes the low-speed and high-torque five-phase permanent magnet machine as the research object,and has done the following work on the five-phase fractional slot centralized winding design,machine body optimization design,multi-physics analysis and prototype processing:Firstly,the design method of the five-phase fractional slot concentrated winding machine is analyzed:the structure and characteristics of the fractional slot concentrated winding are introduced;then the basic mathematical model of the five-phase fractional slot concentrated winding is established by using the winding function theory;based on this model,the expression for suppressing the harmonics of the magnetomotive force from the aspect of suppressing the harmonics of the winding function;then,from the perspective of winding design,the general law of the radial excitation force order of the machine is summarized,including space and time;finally,the modal theory of the machine is analyzed.The analysis has laid a theoretical foundation for suppressing the vibration and noise of the machine.Secondly,the electromagnetic parameters of the five-phase external rotor permanent magnet synchronous machine are designed and optimized.Firstly,with torque ripple,winding factor and magnetomotive force harmonics as evaluation indexes,the advantages and disadvantages of several slot pole number matching types are comprehensively compared;then,according to the performance requirements and size constraints,the preliminary calculation of the machine is performed using the magnetic circuit method.Size,and the electromagnetic finite element model of the machine is established;after that,the Kriging proxy model(Kriging)is established based on the finite element model of the machine.Taking the machine torque as the optimization target,taking the saturation flux density of the key parts of the machine as the constraint,and taking the machine geometric size as the optimization parameter,the optimization problem is established and solved.Finally,the optimization result is analyzed and the design scheme of the machine is determined.Then,the multi-physics field analysis of the five-phase external rotor permanent magnet machine was carried out,the prototype production plan was determined and the prototype was made.First,the electromagnetic field,temperature field and vibration model of the machine are established,and the design scheme is analyzed and verified;secondly,according to the multiphysics field analysis and verification results,the processing scheme of the prototype is determined,and the prototype is made;finally,the design scheme is verified through experiments effectiveness.Finally,the research content of the full text is summarized,and the future work is prospected.