Study of Magnetostrictive Characteristics Based on Dynamic J-A Model under DC Bias

The existence of DC bias will change the magnetostrictive properties of the electrical steel sheet (ESS), thus aggravating the vibration and noise of the transformer core. Based on the theory of magnetic domain and thermodynamics, the dynamic J-A model and the free energy model are combined to construct a dynamic magnetostriction model considering the grain-oriented ESS under DC bias. The parameters are extracted by particle swarm optimization algorithm (PSO). The correctness of the proposed model is verified by comparing the measured and calculated magnetostriction values. Finally, the finite element simulation model of the transformer is established, and the constructed mathematical model of magnetostriction is loaded to simulate the vibration of the transformer under DC bias.