Extraction of B-H relation based on the inverse magnetostatic problem

Abstract

The paper describes a magnetic field inverse problem and an efficient numerical method to solve it. Starting from the experimental flux-current Φ � I data obtained using a non-uniform magnetic field device with known geometry, the B-H nonlinear characteristic of the homogeneous magnetic core is extracted. Both functions B-H and Φ � I are piecewise linear approximated with the same number of breakpoints. The correct formulation (solution uniqueness) of this particular inverse problem is discussed. The method was successfully applied to characterize the ribbon core material of a FLUXSET magnetic field sensor used in Eddy Current Testing. In this case, the hysteresis loop and the equivalent lumped magnetic nonlinear circuit were extracted. Comparison with experimental results validates the proposed method.