Design And Research Of Permanent Magnet Assisted Synchronous Reluctance Motor

With the rapid development of the current era,energy issues have become the focus of social attention.Permanent magnet motor has been widely used because of its high torque density,high power factor and other advantages.However,the general permanent magnet motor uses rare earth materials,which are rare materials.In order to reduce the dependence on rare earth materials and reduce the cost of the motor,people put forward the permanent magnet auxiliary synchronous reluctance motor.The torque generated by the motor is mainly reluctance torque,supplemented by permanent magnet torque.In addition,in order to further reduce costs,ferrite is generally used to replace rare earth materials.Because the motor is greatly affected by the rotor structure,this thesis mainly studies the rotor structure of the permanent magnet assisted synchronous reluctance motor,and optimizes its rotor structure parameters.On the basis of optimization,other performances of the motor are studied.Firstly,the structure and principle of the motor are introduced,and the mathematical model of the permanent magnet assisted synchronous reluctance motor in different coordinate systems,as well as the relevant voltage equation,flux linkage equation,electromagnetic torque equation,etc.are derived.The AC/DC axis magnetic circuit model and the equivalent magnetic circuit model are given,and the main size selection of the motor is introduced.A 6-pole 36-slot permanent magnet auxiliary synchronous reluctance motor with two-layer magnetic barrier is designed.The rated power of the motor is 1.5k W and the rated speed is 1500 rpm.Secondly,introduce Ansys software,simulate the no-load of the motor,and study the no-load electromotive force and cogging torque of the motor.A comparison was made between the maximum cogging torque when using rotor skewed poles and when not using skewed poles,and the cogging torque after rotor skewed poles was significantly reduced.Introduced the rotor magnetic circuit and studied the rotor parameters,analyzed the influence of the magnetic barrier occupancy rate of the motor,the thickness of the magnetic barrier bridge of the rotor,and the magnetic barrier angle of the rotor on torque and torque ripple.Using genetic algorithm to optimize the motor,the results of improved motor torque and reduced torque ripple were obtained.After studying the electromagnetic part of the motor,the temperature of the motor is first analyzed,and the steady-state heat simulation is carried out using Maxwell and Workbench one-way coupling method.The one-way coupling means that the motor loss results obtained from the electromagnetic simulation in Maxwell are transferred to Workbench,and the heat source is used to solve the part to be analyzed in the thermal module.The steady-state heat is that the temperature does not change with the motor operation time.After that,the iron loss before and after optimization is compared.Finally,the temperature distribution of stator,rotor and permanent magnet before and after optimization is compared.After comparison,it is found that the optimized motor temperature distribution is better,which reduces the maximum temperature of motor heating by a lot,and the serious part of heating is also reduced.Finally,the analytical algorithm of electromagnetic force is introduced in detail,and the air gap magnetic density is simulated.harmonic analysis is carried out for its no-load and load conditions.Subsequently,based on the optimization model,simulation research was conducted on the radial electromagnetic force of the motor under both no-load and load conditions,and its spatial order and spectral analysis were analyzed to verify the theory.Compare the frequency components and corresponding amplitudes of the 0-order radial electromagnetic force of the motor before and after optimization,and verify the rationality of the model optimization in Chapter 3.