Research On Hybrid Excitation Linear Eddy Current Damper

When Eddy current damper’s primary and secondary conductor plate haverelative motion, eddy current will emerge in the conductor plate and braking forcewill be produced by the interaction of the eddy current and primary magnetic field.Eddy current damper has advantages of adjustable braking force, high power density,fast dynamic response, low loss, high reliability and can load continuously etc. Eddycurrent damper has very wide application in. Linear motor performance test system,Vehicle suspension system and engineering structural vibration. A hybrid excitationlinear Eddy current damper is presented and analyzed through the analysis methodand finite element method in this thesis. The design method of the eddy currentdamper is proposed and based on that the experimental prototype is made and tested.First, the idling air-gap magnetic flux density expression is derived based onthe magnetic circuit method and the braking force, the loss of the eddy and the fieldwinding resistance expression are derived according to the a layer approach, Thenthe eddy current damper’s analytical model is established. the relationship betweenthe eddy current damper force characteristic curve and main parameters is analyzedand the expression of the critical speed is derived.Secondly, the finite element model of the eddy current damper is established,and magnetic field distribution of the eddy current damper is studied according tothe finite element method. Aiming at maximizing the power density and motorconstant, the main structural parameters of the eddy current damper are optimizedFinally, the design method of the eddy current damper is presented. Theequation of main dimensions is deduced, and the method of determining the size ofthe pitch, tooth width, ampere number of excitation windings, permanent magnetsand other parts is given. The causes of normal force and the relationship betweenthat and the main parameters of electromagnetic damper are analyzed. Theexperimental prototype is made, and the performance of which is tested. The resultsof finite element method and experiment are almost the same, which verify theaccuracy of the finite element model.