Efficient ferromagnetic core impedance model with application to finite-difference time-domain simulation

Abstract

A frequency-dependent impedance model for laminated ferromagnetic cores is presented and analyzed. The model assumes a multiple-winding ferromagnetic induction core composed of multiple thin layers with linear material response. This model builds on the analysis presented by Rose et al. [Phys. Rev. ST Accel. Beams 13, 090401 (2010)PRABFM1098-440210.1103/PhysRevSTAB.13.090401], that determined an equivalent time-dependent resistance that was used to successfully model the loss currents in a linear transformer device cavity containing ferromagnetic cores. The new core impedance model is more general and has been implemented as a surface-impedance boundary condition [K. S. Oh and J. E. Schutt-Aine, IEEE Trans. Antennas Propag. 43, 660 (1995)IETPAK0018-926X10.1109/8.391136] which is suitable for use in multidimensional finite-difference time-domain codes.