Model of laminated ferromagnetic cores for loss prediction in electrical machines

Abstract

An iron-loss model for laminated ferromagnetic cores of electrical machines is presented and applied to estimate the core losses of an induction machine with finite element analysis. Skin effect in the cross section of the core lamination is modeled using a set of sinusoidal basis functions while locally considering both the hysteretic material properties and the excess field caused by domain wall motion. After spatial and time discretization, a single nonlinear equation system is obtained. An accurate vector Preisach model, the differential reluctivity tensor and the Newton-Raphson method guarantee excellent convergence of the iteration procedure. Results from the model correspond well to iron-loss data obtained by measurements.

Analysis of 37-kW Converter-Fed Induction Motor Losses

“…The iron losses are included in the FE solution using the method described in [34]. The loss model is based on solving the flux-density distribution in the thickness of the core laminations taking into account the skin effect of the eddy currents.…”

The Use of Skin Effect for Measurement of Thickness of Sputtered Protective-Coatings

“…As in the given situation, electric field vector E is directed by the z-axis, magnetic field intensity vector H is directed by the y-axis, as well as on the conductor internal surface H(0)=0 and on the conductor external surface H(b)0, then (9) where l -the length of conductor. Impedance of layers {i} and {m}: (10) As both layers of conductor are connected in parallel circuits, then:…”

“…Skin effect reduces the volume of sample and changes its electrical resistance [8]. Modeling of skin effect for solving specific engineering problems is viewed in many authors' publications, for example, in [9] - [16].…”

Model of Magnetic Anisotropy of Non-Oriented Steel Sheets for Finite-Element Method

“…Although their manufacturing process tends to confer isotropic properties [1], [2], magnetic anisotropy has been always observed and recently investigated [3], [4], [5].…”