Simulation And Control Of Amorphous Bearingless Permanent Magnet Synchronous Motor

With the development and progress of modern industry and life,the requirements of motor performance and quality are higher and higher.The performance of traditional motor is limited because of the mechanical friction of bearing.Therefore,in order to improve the performance of motor and to deal with some special working situations,bearingless motor is gradually emerging,which has a considerable prospect in life science,chemical pharmacy,aerospace and other fields.The bearingless permanent magnet synchronous motor has the advantages of no friction,small loss and high efficiency.Applying the amorphous alloy material with high permeability to the stator core of bearingless permanent magnet motor can further reduce the iron consumption and improve the efficiency.In this thesis,the design and simulation experiments of the amorphous bearingless permanent magnet synchronous motor are carried outFirst of all,the research history of bearingless motor and the emergence and development of amorphous alloy materials are reviewed.The research hotspot of bearingless motor and the application status of amorphous alloy in motor are analyzed.On this basis,in order to pursue higher performance,it is proposed to combine the bearingless motor technology with the amorphous alloy material,design the bearingless amorphous motor,select the permanent magnet motor with simple structure and high efficiency,at the same time,in order to simplify the manufacturing process and reduce the space occupied by the winding,the motor adopts the single winding structure.Secondly,the working principle of bearingless motor and the characteristics of electromagnetic force in the motor are analyzed.The principle of levitation force generated by two kinds of magnetic fields with a logarithmic difference of one pole in the motor is explained.The expressions of levitation and torque current in the stator winding of the motor are determined,and the basic structure of the motor is designed.The inductance matrix considering the eccentricity of the rotor in the synchronous coordinate system is derived,and the mathematical model of the motor is listed.For the electromagnetic finite element analysis of the motor,ANSYS software is used to model the bearingless permanent magnet synchronous motor studied in this thesis,observe the magnetic field distribution when each group of current is introduced,calculate the equivalent current value of the permanent magnet,analyze the radial force on the rotor of the motor,observe the characteristics of the controllable suspension force and the unilateral magnetic pull force respectively,verify the accuracy of the suspension force model.By comparing the performance of motor with silicon steel core and amorphous alloy core,it is found that the magnetic induction strength of the teeth of the motor is higher,the magnetic conductivity is better,and the efficiency is higher,especially in the high speed area of the motor,the advantage is more obvious,and the iron consumption is smaller,which verifies the advantages of amorphous material as the motor core,Finally,according to the control method of single winding structure motor and the advantages of multi control degrees of freedom of multi-phase motor,the space vector pulse width modulation technology based on voltage control in torque and suspension biplane is designed.The torque and suspension functions are realized in a set of winding at the same time.Finally,the whole model of motor and its control system is built and simulated in Matlab/Simulink The correctness of the method is proved.The application of amorphous alloy in the stator of bearingless motor further improves the performance of the motor.With the help of the advantages of polyphase motor,the decoupling control problem of single winding bearingless motor is solved ingeniously.Through the further study,it will contribute to the diversity of bearingless motor.