Analysis And Design Of Hybrid Excitation Electromagnetic Damper

The hybrid excitation electromagnetic damper causes the secondary conductor to cut magnetic field lines through the relative motion between the primary and secondary conductors,thereby generating eddy currents within the conductor.The magnitude of eddy current increases with the increase of relative motion speed,and the interaction between eddy currents in the conductor and the primary primary magnetic field generates damping force to suppress this relative motion.Electromagnetic dampers are widely used in the fields of aerospace,electromagnetic braking,linear motor loading systems,and suppression of galloping on overhead transmission lines.This article proposes a new structural scheme of a series magnetic circuit bilateral hybrid excitation linear electromagnetic damper,which has the characteristics of adjustable damping force,high damping force density,small normal force,pollution-free,low loss,high safety,and continuous use.Its damping characteristics are analyzed and studied.Firstly,a novel structure of a series magnetic circuit bilateral hybrid excitation linear electromagnetic damper is proposed,and its working principle and magnetic field distribution are analyzed.Propose an equivalent magnetic circuit model for the damper,and calculate the expression of the air gap magnetic density amplitude based on this magnetic circuit model.The magnitude of eddy current amplitude in the conductor and the induced magnetomotive force generated by the eddy current were calculated based on the equivalent model of the secondary conductor.In order to obtain the damping force expression of the hybrid excitation electromagnetic damper,a layered model was established,taking into account the influence of the primary iron core slotting.The Carter coefficient was used for correction,and the damping force expression was derived by solving the layered model.Taking into account the influence of primary core saturation on the magnetic resistance and damping force expression of each part of the core,an iterative calculation method was used to determine the relative permeability of the magnetic resistance of each part of the primary core.Then,a finite element model of the hybrid excitation electromagnetic damper was established and its model was solved.We studied the magnetic field distribution of a hybrid excitation electromagnetic damper operating at different speeds,obtained the damping force characteristic curve of the hybrid excitation electromagnetic damper through simulation calculation,and analyzed the trend of damping force changes with relative speed.Finally,the effects of different electromagnetic parameters on the damping force characteristic curve and normal force of the hybrid excitation electromagnetic damper were analyzed and compared,and the basic laws affecting the magnitude of damping force and normal force were obtained.The analysis and comparison of hybrid excitation electromagnetic damper and electric excitation electromagnetic damper demonstrate the superiority of hybrid excitation under the same conditions of primary core yoke height,excitation current,air gap length,conductor thickness,and material.The design of a hybrid excitation electromagnetic damper provides a reference for various engineering applications.