High Speed Motor Design With Circumferentially Offset Rotor Of Axial Permanent Magnet Assisted Reluctance

With the development of science and technology,there is an increasing demand for high-speed machine in the fields of aerospace and precision manufacturing.The increase of machine speed is beneficial to increase the power density of the motor and reduce the volume and weight of the equipment.It is a great practical significance to develop direct-drive high-speed motors for national energy security energy conservation and emission reduction,and,it is also a major national strategic demand.In this thesis,a High Speed Motor Design with Circumferentially Offset Rotor of Axial Permanent Magnet Assisted Reluctance(HSM-COR)is proposed as a high speed machine with special structure,which is designed to meet the urgent needs of high-speed machines in various fields and also to improve the interphase magnetic leakage in traditional SRM.The HSM-COR stator and rotor are made of silicon steel sheet laminated with a salient pole structure.The stator is wound with concentrated windings.There are no windings and squirrel cages on the rotor.It has the characteristics of simple structure,high mechanical strength,low cost and high reliability.The rotor structure of HSM-COR can withstand high mechanical stress,which is especially suitable for high speed requirements,and has unique advantages in high speed/ultra-high speed applications such as aerospace and high speed machining.The main research contents of this thesis include the following aspects:(1)By learning from the research results of high-speed machine and new switched reluctance machine at home and abroad,a new type of axial magnetic circuit high-speed machine is proposed.Starting with the new magnetic circuit structure of the machine,the working principle of HSM-COR is analyzed and its torque formula and basic equation are derived by comparing the operating mechanism of the traditional high-speed reluctance machine and the auxiliary excitation doubly salient machine.(2)The overall design process of HSM-COR is divided into magnetic circuit design and permanent magnet auxiliary design.The design theory of traditional high-speed doubly salient machine and the advanced research results of new magnetic circuit structure at home and abroad are used to complete the design of axial magnetic circuit.Based on the body design,the rotor is improved for the interphase magnetic leakage.The simulation results show that the new rotor structure can improve the problem of large torque ripple,and the design target is checked with the simulation results of electromagnetic characteristics.Through the finite element simulation analysis of the motor,the HSM-COR and the traditional SRM have been improved in torque ripple,efficiency and starting speed.The thesis deduces the starting mathematical model of HSM-COR,and analyzes the factors affecting the starting performance.The analysis results are verified based on the analysis of the moment characteristic curve.(3)In order to further test the performance of the motor,the vibration and noise,structural stress,temperature rise experiment and wind friction loss of the motor are analyzed by using multi physical field simulation software,and the rationality of the motor structure is verified.Based on the axial magnetic circuit,the idea of permanent magnet auxiliary is proposed.The thesis determine the solution of using the axial magnetic circuit and the auxiliary permanent magnet cooperating with each other,and perform the electromagnetic characteristics simulation analysis and performance impact analysis on the effect.