Design Of A New Type Of Mechanical Variable Flux Permanent Magnet Synchronous Machine With Rotating Pole

The traditional PM machine has the performance of simple structure,reliable operation,high torque and high efficiency,but there is a problem that the magnetic field is difficult to adjust.Therefore,this paper innovatively proposes a novel mechanical variable flux permanent magnet synchronous machine with rotating magnetic pole(NMVFPMSM-RMP).This machine adopts the way that the magnetic adjustment device and the machine structure cooperate with each other in space to achieve weak magnetic field.The designed machine structure and magnetic adjustment device have strict size requirements.Field weakening can be achieved by NMVFPMSM-RMP,and provide a new method of magnetic regulation,which lays a certain theoretical foundation for the difficulty of weak magnetic field of PMSM.The content of this article is mainly divided into the following aspects:1.A reasonable NMVFPMSM-RMP.Three different topological structures are designed.Three topologies have the same inside and outside diameters of the rotor,the same stator structure and the same amount of the permanent magnet,but the rotor structure is different.Electromagnetic simulation and comparative analysis of the three topological were carried out by Maxwell.the machine structure suitable for the design requirements of this paper was determined.2.The working principle of NMVFPMSM-RMP and magnetic adjustment device has studied.The structure size of novel machine was preliminarily determined by the equivalent magnetic circuit method,and the magnetic field of the cylindrical PMs were discussed.The magnetic induction intensity and the simulation result of the cylindrical PMs are determined by Biot-Savart's law and MATLAB software.3.Structure optimization of NMVFPMSM-RMP.In order to obtain high electromagnetic torque,it is necessary to increase the difference of the inductance of the orthogonal axis to increase the reluctance torque.Therefore,according to the regression design method,the structure of NMVFPMSM-RMP is optimized with finite element analysis software.Including the radius of the cylindrical PMs,the value of the length and width of the inline PM,the stator slot,the length of the unilateral air gap,etc.Finally,the inductance of the orthogonal axis under different currents is obtained.By calculating the machine has a higher electromagnetic torque.4.Dynamic simulation of virtual prototype model.A virtual prototype model was established by Adams for dynamic simulation.The time-varying curve of spring deformation,the curve of gear rotation angle with different speeds and the maximum angle that the gear could rotate was obtained.5.The analysis of the field weakening principle of NMVFPMSM-RMP.The electromagnetic simulation of the cylindrical PMs with different rotation angles are carried out through finite element analysis software.It can be seen that the machine has good weak magnetic expansion performance.6.Research the mechanical strength of the rotor and stator electromagnetic vibration.Based on the theoretical analysis of statics,the Workbench first performs dynamic simulation on the rotor,and then equivalently converts the simulated structure into the static field to simulation,the total deformation cloud and stress cloud of the rotor are obtained at the rated speed;on the basis of discussing the vibration of the machine,analyze the principle of electromagnetic force.The stator simulation model is established by SolidWorks software.Finally,the displacement cloud diagrams,stress cloud diagrams and harmonic response curve at different frequencies are obtained with electromagnetic coupling.