Conference Agenda

Electromagneto-quasistatic (EMQS) fields, where capacitive, resistive, and inductive effects are considered in the absence of radiation effects, can be modelled using the Darwin-Ampère equation. Here, a systematic approach is proposed for deriving distinctly gauged scalar-vector potential formulations for EMQS fields. In view of the proposed methodology, the resulting EMQS field models not only cover established Darwin-type formulations, but also introduce novel formulations. Numerical experiments show the validity of such EMQS approximations in comparison to full Maxwell field simulations.

Formulations in terms of scalar potentials are proposed to solve the static field problems occurring when computing the parameters of a Cauer ladder network representation of two-pole devices involving eddy-current effects. The curl-equations are satisfied by efficiently generating vector potentials describing the known flux density and current density and introducing unknown scalar potentials to represent the electric and magnetic field intensities. The scalar potentials are approximated using nodal basis functions in the finite-element realization, leading to Poisson equations to be easily solved. A simple numerical example illustrates the method.

This paper proposes an adaptive equivalent RL-circuit to model eddy-current devices with a single electrical port (one terminal voltage and current) and a translational movement. The device is first characterised by means of frequency-domain finite-element computations considering the relevant frequency interval, for subsequently fitting constant-coefficient RL ladder circuits of adjustable size (i.e. number of branches and loops). The accuracy of the ladder-circuit model is assessed in both frequency and time domain. By way of validation, we study the axisymmetric magnetic-levitation device of TEAM Workshop problem 28.