| High-speed Permanent Magnet Synchronous Motor(HSPM)has become a popular research object in the field of motors in recent years due to its high-power density,high efficiency,high compactness,high reliability and fast dynamic response.Aiming at the special problems of HSPM in electromagnetic,mechanical and thermal,this thesis comprehensive design of multi-physics and its optimization method as the core content to carry out a series of related researches.Based on the research status at home and abroad,this thesis studies the loss calculation and suppression technology of HSPM,thermal management technology,rotor bearings,rotor dynamics analysis and multi-physics optimization method,meanwhile gave the HSPM multi-objective optimization design method based on multiple physical fields.First,the special design method of high-speed motor was studied to establish a comprehensive design system of HSPM multi-physics.In order to compare with the sensitivity analysis of multi-physics optimization results,the influence of main parameters of the motor on power density and efficiency was studied,and the electromagnetic model of the motor was established and the preliminary motor scheme was given.Secondly,the loss calculation method and suppression method of HSPM were studied,and the variation rule between loss and electric was analyzed.The simplified thermal network model of HSPM was built by analyzing the heat transfer mode inside the motor.The cooling structure of HSPM was designed and optimized,and the temperature distribution of the motor was studied by electromagnetic field and fluid field coupled.Thirdly,the strength of the rotor was analyzed and calculated by the method of finite element analysis and theoretical analysis.The influence of key parameters such as sleeve thickness,interference between sleeve and permanent magnet,and sleeve edge length on rotor stress distribution was analyzed by finite element method.On this basis,the rotor dynamics was analyzed,the critical speed of the rotor was calculated,and the strength and dynamic stability of the rotor were evaluated.Finally,based on ANSYS platform,combined with electromagnetic calculation,loss calculation,the temperature rise calculation and the rotor stress calculation,the objective function and constraints of HSPM multiphysics multi-objective optimization design were analyzed and given.And the NSGA-? algorithm was used to realize optimization calculation of HSPM.The results showed that the multi-objective optimal design method based on multi-physics can effectively improve the power density and efficiency of HSPM,and improve the design accuracy and time efficiency. |
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