Inductance Modeling And Magnetic Field Analysis Of A Reluctance Spherical Motor

Spherical motor(SM)is a kind of special motor which can complete three degrees of freedom movement.It has a wide range of application prospects in the fields of medical treatment,monitoring,industry,aerospace and so on,meanwhile has gradually attracted the close attention of experts at home and abroad.However,due to the three-dimensional structure,the permanent magnet SM has many problems such as complicated control,limited output torque and difficult position detection.Therefore,starting from the structure design,to further improve the performance of the SM has become a hot topic.Based on the principle of minimum reluctance,a new type of reluctance spherical motor(RSM)is proposed in this paper.The inductance analytical modeling and electromagnetic analysis of the motor are completed,and the rationality and effectiveness of the analytical method are verified by prototype experiments.The main work of this thesis are as follows:1)Firstly,the basic structure of the RSM is introduced,then the three-dimensional coordinate system is established on the stator and rotor respectively,and the motion principle of the motor is elaborated in detail in two basic motion states of spin and tilt.It is concluded that the rotation direction of the motor is independent of the power on direction,but related to the power on sequence.2)According to the energy method,the basic mathematical model of the RSM is derived.The results show that the output torque of the motor is related to the deflection of the inductance to the space position angle.Then,the inductance model is established without considering the magnetic saturation and considering the magnetic saturation,and the results are compared.3)In order to calculate the magnetic field of the motor accurately,the finite element model of the RSM is established.On this basis,the torque angle characteristics of two basic motion states with single coil energized are analyzed,and the influence of non-deflection position angle on motor motion is discussed.4)The parts of the motor are fabricated and assembled into a prototype.Using the spherical motor experiment platform,the open-loop experiment was completed,and the torque output of analytical method,finite element method and experimental measurement were compared and analyzed,which provided some ideas for the design of the relevant spherical motor and laid a foundation for the optimization and control of the motor.