The Study Of Nonlinear Transient Magnetic Field Coupling With Mechanical Movement

Many works on 2D non-linear transient magnetic field coupling with mechanical movement, including theoretically mathematical formulation, algorithm, program and experiment, are mainly researched in this paper with the FEM theory, and some valuable results to theory analysis and engineering designing have been gained.In the first part of the paper, the study survey of transient questions in electromagnetic field is introduced. The development of Permanent Magnetic Actuator (PMA) and its calculation dynamic characteristics are discussed. Secondly, some recently research results and some unsolved problems about the magnetic vector potential A, electric scalar potential Φ and magnetic scalar potential ψ of the transient eddy current formulation are deeply analyzed in the paper and the magnetic vector potential A is chosen to calculate the specified physical model discussed in this paper. The paper proves that in the 2D non-linear case, the coulomb gauge is been meet naturally.In the paper, the second-order isoparametric FEM is adopted in the non-linear transient magnetic field simulating excited by current source and the results of transient field and static field solved by the second-order isoparametric and linear FEM are compared and analyzed, besides, the effect of the eddy currents in the magnetic materials of the different conductivity is analyzed, it is obtained that the magnetic material of high magnetic conductivity and low loss should be chosen in designing of PMA.The mathematical model of non-linear transient magnetic field excited by voltage source is established in this paper. It coupled with electric circuit equation and mechanical motion equation, could solve the transient problem excited by voltage source, and the effect of the eddy currents, non-linearity in magnetic materials and mechanical motion of medium is taken into account. The calculation results of direct coupling and sequential method and test results are compared, it is proved that direct coupling is more advantageous and the calculation results are more accuracy than thatof sequential method.In addition, the magnetic force of the different structure PMA and saturation characteristic of magnetic material are analyzed in this paper, that provide valuable results for the design and optimization of PMA.