Analysis And Application Of Eddy Current In Motion Systems

With the development of national industrialization,the design and research of electromechanical systems get more and more attention.There exist permanent magnet or coil and conductive non-magnetic metal block structure in many electromechanical systems.It is necessary to consider the eddy current effect when there is a mutual movement between permanent magnet(or coil)and metal block in these motion systems.This thesis does some research and analysis on eddy current distribution and force calculation if there exists any eddy current in motion systems.Defining the polarization direction of the magnetic source as Z axis,the eddy current model along arbitrary direction of movement is decomposed into eddy current model along axial and radial direction based on velocity vector decomposition.Through the Faraday electromagnetic induction law and Lenz's law,the distribution of eddy current in two models is analysised;through the magnetic force equation and the magnetic vector potential function equation,eddy current density formulation and force formulation are established.Using DMC model,a numerical calculation method to solve eddy current models has been established,and compared with the results of commercial software COMSOL.The eddy current model along arbitrary direction of motion can be obtained by two kinds of models.After analyzing theoretical model,the bending vibration experiment of the cantilever beam and the rotating disc experiment are carried out to verify the accuracy of the two models above.Finally,the eddy current model has been applied to solve problems encountered in the direct drive spindle motor of double turning project: calculating the reaction torque in the rotation of the direct drive spindle motor and the design of vibration suppression device when turning titanium alloy disc.