Low-Order Dynamic Magnetic Equivalent Circuits of Saturated Steel Laminations

Abstract

Physics-based modeling of laminated magnetic Recently, physic-based magnetic-equivalent circuit devices accurately represents underlying dynamic (MEC) models of magnetic devices are shown to be a characteristics. However, these models are hard to formulate, potential design tool for power propulsion systems [5], [6]. oversimplified with crude approximations, and In this approach, the magnetic core is represented by computationally intensive. In this paper, a high-fidelity . ' .magnetic equivalent circuit of steel lamination is set forth appropritse magnetic-ain estaemae inducainc based on geometrical and material data. The nonlinearity components, where magnetic and external electric domains imposed by saturation is also considered. Automated linear are coupled through the flux linkage-current relationship and nonlinear order-reduction techniques are introduced to (A-i) (see Fig. 1 (a)) [7]. Since lamination changes the mathematically extract the essential system dynamics in the eddy current's effective path, a laminated magnetic structure desired bandwidth, thus preserving both accuracy and is represented as parallel magnetic cores (Fig. 2 (b)). In the computational efficiency. The resulting reduced-order system presenteddyparel magnetc core is 2 Into is validated with hardware measurements and full-order presence of eddy current, the magnetic core iS diVided intO simulation in both time and frequency domains. concentric zones, each carrying flux perpendicular to the zone and behaving as a current sheet circulating around the Keywords -Eddy Current, Electrical Machines, Lamination, cross section (Fig. 2 (c)) [7]. Each zone is modeled as a Magnetic-equivalent circuit, Nonlinear order-reduction, Satmagnetic-domain R-L pair (Fig. 2 (d)), where Rk represents uration, Vehicular electrical systems. the kth zone flux path reluctance, and transference Gk accounts for the conductivity of the kth zone eddy-current