Study On Hysteresis Characteristics Of Soft Magnetic Materials Using Finite Element Numerical Simulation And Experiment

Firstly,two improvement methods of Preisach hysteresis model were proposed.One was to establish a kind of Preisach model based on the limit hysteresis loop,using the variable separation of Preisach distribution function,which can convert the double integral of Preisach distribution function to a single integral and greatly simplify the implementation of Preisach model.The other method was to use the limit hysteresis loop of soft magnetic materials to generate the first-order curve and Everett function instead of solving double integrals.Thus,Preisach model based on the Everett function was established,which was simple and accurate.Secondly,a kind of efficient extraction method of statistical parameters of excess loss was proposed.Based on the statistical theory,the analytical expression of the excess field intensity component corresponding to the excess loss was derived,and then coupled with a kind of dynamic magnetic viscosity model,where the analytic expression of the magnetic field intensity components of the excess loss can be deduced.the experimental results were used to verify the accuracy and practicability of the proposed efficient extraction method.Then,a kind of method was put forward which can consider the influence of skin effect to eddy current loss of silicon magnetic ring.Basing on the vector magnetic potential A,coupling the hysteresis model and the time domain finite element equation,using the fixed point technology and introducing the differential magnetic resistance rate to solve local convergence solution of finite element equations,the magnetic hysteresis loss and eddy current loss of the silicon magnetic ring were calculated under the sine excitation.To solve the difficulty of parameter extraction of excess loss,the paper selected rational function to fit the excess loss parameters according to the relationship between statistical parameters of excess loss V0 and peak of ac magnetic flux density Bp.Thus the residual loss can be calculated accurately.Finally,to analysis the impact of stress on the Preisach distribution function,the rational function was selected to fit the relationship between the stress and the Preisach distribution function.Thus the goal of simulation and the calculation of magnetic hysteresis characteristics under different stress was achieved,and the simulation results were compared with the experimental measurement.The proposed algorithm could be used for loss calculation of soft magnetic materials under high frequency sine excitation and different stress,and the accuracy was good.