Characteristic Analysis And Optimization Design Of Surface-mounted And Interior Permanent Magnet Synchronous Motor

The surface-mounted and interior permanent magnet synchronous motor(SIPMSM)adopts series-parallel magnetic circuit structure,which integrates merits of traditional surface-mounted permanent magnet synchronous motor and interior permanent magnet synchronous motor,have wide application prospect.The paper focuses on the new type motor,the mechanical properties and magnetic characteristics are optimized,and the 3-D temperature filed and the ways of line-start are researched.Main research contents of the paper are as follows.1.The sinusoidal characteristics,cogging torque,torque ripple and power factor are simulated and analyzed for the different magnetization and the structure models of SIPMSM.The surfaced permanent magnet of SIPMSM is optimized adopting the finite element method.The different magnetizations and the structure models are established to compute the transient field,and the air gap flux density distribution of pole pitch is researched at rated station.The sinusoidal characteristics,cogging torque,torque ripple and power factor are simulated and analyzed for the different magnetization and the structure models,and the optimal magnetization and structure models are confirmed.The results show that the performances of SIPMSM are improved efficiently.2.The cogging torque of SIPMSM is optimized adopting skewed slots,and characteristics of SIPMSM with skewed stator slots and straight stator slots are analyzed.The theory that the resultant cogging torque was associated with the synthesis of a single stator slot was applied,the single slot analytical expression and the resultant cogging torque analytical expression were derived,and the skewed numbers of stator slots was solved.The three-dimensional finite element model of SIPMSM with skewed slots or straight slots were established,respectively.The cogging torque,torque ripple,back electromotive force,power-angle characteristics,efficiency and power factor of SIPMSM with skewed slots were analyzed.The cogging torque was weakened effectively,the torque ripple was reduced and the sinusoidal characteristic was improved.3.Taguchi is introduced to realize multi-objective optimal design of SIPMSM.The taguchi is introduced to realize multi-objective optimal design of SIPMSM.Cogging torque,electromagnetic torque ripple,ratio of between average torque and permanent magnet weight as well as product of between efficiency and power factor are chose as optimization targets,optimization parameters and impact factor of SIPMSM which have obvious effect on optimization targets are determined.The orthogonal matrix for optimization parameters and optimization targets is established to analyze the effect of parameters on target characteristics,finally,optimization parameters combination making best comprehensive performances is seek out.Comparing the characteristics of after and before optimization objectives,the results show that comprehensive performances of SIPMSM are highly improved.4.The coupling analysis of electromagnetic field and temperature field is adapted to calculate 3-D temperature field distribution of SIPMSM with different work states.The coupling analysis of electromagnetic field and temperature field is adapted to calculate 3-D temperature field distribution of SIPMSM.Finite element models of electromagnetic field and temperature field are established to analyze the influences of load and permanent magnet demagnetization on 3-D full-domain temperature field of SIPMSM at synchronous speed,the influences of various speed on 3-D full-domain temperature field of SIPMSM with rated load are also analyzed.5.A kind of line-start SIPMSM is presented,the dynamic,steady state performances of LSSIPMSM with PMs of different heights,canned conducting layers of different thicknesses and different demagnetization condition were investigated.This paper presents a kind of line-start surface-mounted and interior permanent magnet synchronous motor(LSSIPMSM),which has a canned conducting layer made of copper between the surface-mounted PMs and rotor core.The LSSIPMSM performances were analyzed and the key parameters were optimized based on combinations of analytical method and finite element method.The dynamic,steady state performances of LSSIPMSM with PMs of different heights and canned conducting layers of different thicknesses were investigated,finally,the optimal parameters were obtained.Electromagnetic finite element model of the LSSIPMSM were established to analyze the starting capability and steady state synchronization,and the temperature field of LSSIPMSM with different demagnetization condition was researched by 3-dimensional temperature finite element model.The results show that LSSIPMSM has good dynamic and steady state performances.