Optimal Design And Control Of Synchronous Reluctance Motor

In recent years,synchronous reluctance motor(SRM)has been widely concerned in the field of low-cost AC speed regulation because of its advantages of low cost,simple fabrication and stable structure.In the process of designing SRM,because of the large number of parameters to be optimized and the complexity of rotor topology,it often needs a lot of finite element modeling and calculation to design a motor that meets the requirements,which results in a long design period of SRM.In addition,due to the limitation of the excitation system structure of the motor,there are some disadvantages of the synchronous reluctance motor,such as small power factor and large torque ripple.In the control of the synchronous reluctance motor,the control accuracy of the motor is low,and there is a big deviation between the actual running state and the preset state.In order to solve these problems,this paper will study the design,structure optimization and control of SRM,Firstly,this paper determines the size of the main structure size of the motor by genetic algorithm.The main dimensions and stator winding parameters of the motor with different pole slots are calculated.Then,based on the calculation results of genetic algorithm,the finite element models of the motor with different pole slots are built respectively.The influence of the magnetic circuit structure of the motor on the performance of the motor is analyzed by combining analytical calculation and finite element calculation.Through the combination of genetic algorithm calculation,analytical calculation and finite element calculation,this paper avoids the problem of repeated modeling of finite element calculation and greatly reduces the design cost of SRM.In addition,this chapter uses the finite element method to calculate the output torque and torque ripple of the motor in different magnetic barrier layers,different coefficient of magnetic barrier crack ratio and different shape of magnetic barrier,and finally gets the design scheme of synchronous reluctance motor which meets the design requirements.Then,this paper analyzes the distribution of the air gap magnetic field of the motor,calculates the radial magnetic field and the tangential magnetic field by the finite element method,and on this basis,calculates the relationship between the magnetic field energy and the torque ripple when the rotor position of the motor changes.According to the calculation results of magnetic field energy,this paper calculates the influence of pole arc coefficient on torque ripple,and uses the finite element method to verify,and optimizes the pole arc coefficient of the motor.In addition,according to the expression of magnetic field energy,two strategies of optimizing torque ripple are put forward in this paper,which are auxiliary slot and rotor pole optimization.By using the finite element simulation,the restraining effects of stator auxiliary slot,rotor auxiliary slot,asymmetric pole and pole offset on torque ripple are analyzed respectively,and the better rotor structure is obtainedAt last,the mathematical model of SRM is established,the basic principle of vector control strategy in SRM is analyzed,the specific reason of low control precision of SRM is found,and the penalty function is introduced to solve the problem of insufficient control precision of SRM.In addition,the paper uses the finite element method to calculate the AC and DC shaft inductance at different current.Through curve fitting,the function expression between the AC and DC shaft inductance and the AC and DC shaft current is determined,and the AC and DC shaft current distributor is designed accordingly.In the end,this paper models and simulates the motor in Simulink,and validates the effect of PI regulator with penalty function.The results show that the input current of the motor can be reduced by introducing penalty function,and the actual working point is closer to the preset working point.In addition,the penalty function is introduced to improve the PI regulator of the motor,and the corresponding current is also reduced in the starting process.