横向磁通永磁直线电机电磁振动特性分析

As the only power source of the reciprocating submersible pump system, the operation performance of the submersible linear motor directly affects the operation performance of the whole pump system. Therefore, the selection of linear motor is particularly important. As a special motor with high thrust density, transverse flux permanent magnet linear motor (TFPMLM)benefits from the transverse flux structure, the electrical load and the magnetic load are mutually decouped and each phase is mutually decouped, and the motor is easy to achieve modularization and multiphase, based on the above characteristics, TFPMLM is more suitable for application in the field of oil exploitation. In the actual process of oil exploitation, the disturbance from the outside of the motor and the vibration of the motor will lead to the reduction of the insulation of the motor and thus reduce the service life of the motor. In order to solve the vibration problem of TFPMLM, the radial electromagnetic force wave of TFPMLM is derived in this paper, and then the eccentricity problem which may occur in the operation of the motor is studied. Finally, the primary mode and electromagnetic vibration characteristics of TFPMLM are analyzed and summarized. Firstly, the electromagnetic wave of TFPMLM is analyzed, and the expressions of the primary and secondary permeability and magnetomotive force of the motor are obtained by using the principle of magnetic field modulation, and the magnetic density of the air gap is obtained. On this basis, the magnetic density of the synthetic air gap is obtained by considering the role of the armature winding. Maxwell stress tensor method was used to obtain the expressions of electromagnetic force waves acting on the primary teeth in all directions. Then, according to the principle of linear superposition of magnetic density, the air gap magnetic density was decomposed into armature magnetic density, primary permanent magnet magnetic density and secondary permanent magnet magnetic density. By combining the above expressions, the simplified mathematical expression of radial electromagnetic force waves was finally obtained. Then the temporal and spatial characteristics and spectral characteristics of radial electromagnetic waves are simulated and the influence of armature magnetic density on the spectral characteristics of radial electromagnetic waves is obtained. Secondly, in view of the secondary eccentricity which may be caused by motor vibration, the influence of eccentricity on electromagnetic wave spectrum characteristics is analyzed, and the results show that the secondary eccentricity has greater influence on the 3rd and 6th order harmonics. By comparing the radial magnetic pull and axial electromagnetic force wave of the motor under different eccentricity, it is concluded that when the secondary eccentricity fault occurs, a large unilateral magnetic pull will be generated in the radial direction of the secondary, and the amplitude of thrust fluctuation will increase. Finally, in order to avoid resonance, the modal analysis and harmonic response analysis of the primary of TFPMLM are carried out. The results of modal analysis show that the motor will not resonate due to electromagnetic force. The results of harmonic response analysis show that compared with the primary teeth, the electromagnetic force wave has a greater impact on the outer surface of the primary circumference.