Conference Agenda

A motor model order reduction (MOR) based on the decomposition into stator and rotor domains requires a large number of spatial harmonic components of the airgap field to connect the two domains accurately. This article proposes a simple method for selecting dominant spatial harmonics at the airgap, where a time-harmonic eddy-current analysis of an induction motor is carried out before constructing stator and rotor reduced systems. Simulation results show that the proposed method gives an efficient and accurate reduced model of a squirrel cage induction motor.

In this work, we discuss a novel tree-cotree-based regularization technique which corresponds to a generalized Coulomb gauge considering the material distribution. The method is explored in the context of a low-frequency stabilized full Maxwell formulation.

Simulating magneto-thermal transients in superconducting magnets is important for the design of quench protection systems, but is challenging and computationally expensive due to the multi-scale structure of these magnets and the strongly nonlinear behavior of superconducting materials. In this contribution, we describe a general homogenization technique allowing to reproduce the macroscopic effects of the small-scale field and current dynamics in superconducting strands and cables without a need to compute them explicitly in the magnet model. This leads to a substantial reduction of the computational effort compared to conventional fully detailed models. The approach relies on simulations at the conductor level (strand or cable), whose results are used to define equivalent homogenized model parameters describing magnetization, loss and inductance. These parameters include hysteretic components inspired by state-of-the-art vector hysteresis models for ferromagnetic materials.

In this contribution, we extend the foil winding homogenization method to magnetic field conforming formulations. First, we propose a full magnetic field foil winding formulation by analogy with magnetic flux density conforming formulations. Second, we introduce the magnetic scalar potential in non-conducting regions to improve the efficiency of the model. The proposed models are validated on a benchmark problem.

This paper describes a variant of the FEM-DBCI (Finite Element Method – Dirichlet Boundary Condition Iteration) method for the solution of low-frequency electromagnetic problem in open boundaries. The unbounded free space around the system is truncated by means of a fictitious boundary and the finite element method (FEM) is applied in the bounded domain, by assuming that an unknown Dirichlet condition holds on this boundary. This condition is expressed by means of an integral equation which involves the free space Green’s function. The integration surface is selected in the middle of the most external layer of finite elements, very near to the truncation boundary, so that the integral equation becomes quasi singular (Quasi Singular DBCI ,QSDBCI). The hybrid global algebraic system is solved by means of an iterative algorithm, by which a first guess for the unknown Dirichlet condition is iteratively improved. The method is suitable for the solution of electrostatic, magnetostatic, skin effect and eddy current problems. Comparisons are made with the FEM-BEM, concluding that FEM-QSDBCI is very competitive.