Showing papers by "Floran Martin published in 2017"

Modeling the Effect of Multiaxial Stress on Magnetic Hysteresis of Electrical Steel Sheets: A Comparison

Abstract: The abilities of a simplified multiscale and a Helmholtz energy HE models models from the literature to predict the multiaxial stress dependent magnetic hysteresis behavior of electrical steel sheets are analyzed. The identification of the models is performed using only uniaxial magneto-mechanical measurements. Reasonable accuracy between the measurements and the modeled results is obtained. With this paper, the applicability of the HE-based model for predicting the multiaxial magneto-mechanical behavior of electrical steel sheets is verified for the first time. The differences between the studied models and possible modifications to increase the accuracy of them are discussed. Some brief guidelines for the applications are given.

Constrained Algorithm for the Selection of Uneven Snapshots in Model Order Reduction of a Bearingless Motor

Abstract: Electromagnetic force and torque computations for a bearingless synchronous reluctance motor present multi-input complexity due to the levitating auxiliary winding located in the machine active parts. The machine model complexity is reduced through the proper orthogonal decomposition method. For this purpose, a snapshot matrix is needed to be constructed. This paper proposes a methodology of choosing efficient snapshots for the model order reduction. The reduced model is then applied to compute the torque and electromagnetic forces on the rotor of the machine. The method presented for selecting the snapshots is shown to be more efficient than uniformly distributed snapshots and it reduces the number of finite element method evaluations needed for the construction of the reduced model.

Modelling anisotropy in non-oriented electrical steel sheet using vector Jiles–Atherton model

Abstract: Purpose Non-oriented electrical steel presents anisotropic behaviour. Modelling such anisotropic behaviour has become a necessity for accurate design of electrical machines. The main aim of this study is to model the magnetic anisotropy in the non-oriented electrical steel sheet of grade M400-50A using a phenomenological hysteresis model. Design/methodology/approach The well-known phenomenological vector Jiles–Atherton hysteresis model is modified to correctly model the typical anisotropic behaviour of the non-oriented electrical steel sheet, which is not described correctly by the original vector Jiles–Atherton model. The modification to the vector model is implemented through the anhysteretic magnetization. Instead of the commonly used classical Langevin function, the authors introduced 2D bi-cubic spline to represent the anhysteretic magnetization for modelling the magnetic anisotropy. Findings The proposed model is found to yield good agreement with the measurement data. Comparisons are done between the original vector model and the proposed model. Another comparison is also made between the results obtained considering two different modifications to the anhysteretic magnetization. Originality/value The paper presents an original method to model the anhysteretic magnetization based on projections of the anhysteretic magnetization in the principal axis, and apply such modification to the vector Jiles–Atherton model to account for the magnetic anisotropy. The replacement of the classical Langevin function with the spline resulted in better fitting. The proposed model could be used in the numerical analysis of magnetic field in an electrical application.