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In this paper, a stabilized reduced-order model based on the gappy proper orthogonal decomposition (POD) technique is applied to an eddy-current problem with the non-linear material property. A classical magnetodynamic finite element formulation based on the magnetic vector potential is used as reference and starting point to build up the reduced models. The computational complexity of the non-linear problem might be reduced by the discrete empirical interpolation method-POD technique, but the eddy current effects may make this method unstable. In this paper, we propose an approach which is similar to the gappy method to successfully overcome this instability problem, while keeping the computational cost (time and memory) low. [ABSTRACT FROM AUTHOR]

This paper deals with the harmonic-balance (HB) finite-element (FE) analysis of a multi-turn winding device coupled to electrical circuits comprising nonlinear components. The eddy-current effects in the windings are accounted for via a frequency-dependent reluctivity and impedance determined with a homogenization technique. The proposed multi-frequency approach is validated through a single-phase four-diode rectifier with an axisymmetric FE model of an inductor. The system of nonlinear algebraic equations is solved by means of the Newton–Raphson method. The HB results are validated with classical time-stepping simulations. The computational cost is briefly discussed. [ABSTRACT FROM AUTHOR]

Electrical machines with stranded random windings often suffer from considerable circulating current losses. These losses have been poorly studied because of the difficulty and computational cost of modeling stranded windings, and the stochastic nature of the problem due to the uncertain positions of the strands. This paper proposes two methods to model random stranded windings of arbitrary complexity. First, a circuit model considering the entire main flux path is presented, and some practical implementation considerations are discussed. Second, a computationally efficient finite-element approach based on non-conforming meshing is presented. Finally, a method is proposed to model the random packing process of strands within a slot, without any remeshing or inductance recalculation required. The proposed methods are then compared with special no-rotor measurement data of a large number of high-speed induction machines, and good agreement is observed. [ABSTRACT FROM PUBLISHER]

This paper presents the generation of equivalent circuits from a finite-element (FE) model of electromagnetic devices using proper orthogonal decomposition (POD). This method effectively computes the frequency response of the reduced FE model constructed by the POD-based model order reduction. Then, the circuit parameters are determined so as to minimize the error between the frequency responses of the reduced FE model and equivalent circuit. The frequency characteristics of an inductor and the induction heating machine evaluated by the equivalent circuit are shown to be in good agreement with those computed from the original FE model. [ABSTRACT FROM AUTHOR]

A volume integral formulation using facet elements to compute eddy currents in thin conductive shells is presented. The formulation is general and considers the field variation through the depth due to the skin effect. The formulation leads to an equivalent lumped elements circuit that can be coupled with an external circuit. The resolution of the circuit is achieved by the independent loops method. The formulation has been validated because of two numerical examples. Results are compared with an axisymmetric finite-element method (FEM) and another shell formulation implemented in a 3-D FEM. [ABSTRACT FROM PUBLISHER]