| With the development of pure electric vehicles,the research of high performance permanent magnet synchronous motor(PMSM)has attracted wide attention of scholars.Due to the increasing speed of PMSM used in pure electric vehicle drive,the influence of high frequency iron consumption on motor efficiency is increasing.Torque capacity and performance of motor,as well as electromagnetic vibration and noise are also important contents to evaluate the performance of motor.Therefore,the research on improving the performance of PMSM for pure electric vehicle by slotting rotor has certain theoretical and practical significance.Chapter 1 summarized the main points and methods of high performance analysis of permanent magnet synchronous motor based on the research of domestic and foreign scholars.Combining with the current research situation,three research points were put forward and the work of this paper was arranged.In Chapter 2,the effect of slot shape and arrangement of magnets on iron loss of PMSM was studied by field-circuit method.The tangential slotted rotor structure motor was established,the stator iron loss was calculated by analytic method,and the hysteresis loss coefficient was revised.Then different rotor models were established,and the variation law of iron loss was studied by finite element simulation.In Chapter 3,the torque capability,performance and cogging torque of PMSM were studied.The cogging torque was analyzed by analytic method,and the relationship between the amplitude of cogging torque and air gap flux density was obtained.The radial slotting,tangential slotting and surface slotting of single-layer and double-layer magnet rotor were studied by finite element method,and the variation rules of torque capacity,performance and cogging torque were obtained.Four kinds of better rotor structures were compared comprehensively.Chapter 4 studied the electromagnetic vibration and noise of four kinds of rotor structure motors.The inherent modal analysis of the stator and rotor of the motor was carried out by using finite element method.The critical speed was calculated by the inherent modal frequency of the rotor.The magnitude of the critical speed and the rated speed was compared,and the resonance degree between the motor and the rotor was judged when the motor was running.The no-load,load radial space and time of four kinds of rotor structures were discussed.Electromagnetic force wave,the influence of different rotor structure motors on pole multiple harmonic amplitude was compared,the vibration acceleration and noise of four motors under no-load and load were analyzed,the vibration and noise of four motors were compared,and the optimal rotor slotting mode was obtained.In chapter 5,the prototype of PMSM was made and experimented.The tangential slotted rotor was redesigned for the 3.7kW motor in the laboratory.In order to verify the rationality of the prototype and the reliability of the finite element analysis method,no-load power generation and electric experiment,no-load iron consumption test experiment,natural mode and vibration and noise experiment were carried out on the prototype.The reliability of simulation methods and results was verified by comparing the experimental and simulation values..Chapter 6 summarized the whole paper. |
