Valentin Hanser, Markus Schöbinger and Karl Hollaus
This work introduces an efficient and accurate technique to solve the eddy current problem in laminated iron cores considering vector hysteresis.
Abstract
Purpose
This work introduces an efficient and accurate technique to solve the eddy current problem in laminated iron cores considering vector hysteresis.
Design/methodology/approach
The mixed multiscale finite element method based on the based on the T,Φ-Φ formulation, with the current vector potential T and the magnetic scalar potential Φ allows the laminated core to be modelled as a single homogeneous block. This means that the individual sheets do not have to be resolved, which saves a lot of computing time and reduces the demands on the computer system enormously.
Findings
As a representative numerical example, a single-phase transformer with 4, 20 and 184 sheets is simulated with great success. The eddy current losses of the simulation using the standard finite element method and the simulation using the mixed multiscale finite element method agree very well and the required simulation time is tremendously reduced.
Originality/value
The vector Preisach model is used to account for vector hysteresis and is integrated into the mixed multiscale finite element method for the first time.
Details
Keywords
Markus Schöbinger, Karl Hollaus and Joachim Schöberl
This paper aims to improve the efficiency of a numerical method to treat the eddy current problem on a laminated material, where using a mesh that resolves each individual…
Abstract
Purpose
This paper aims to improve the efficiency of a numerical method to treat the eddy current problem on a laminated material, where using a mesh that resolves each individual laminate would be too computationally expensive.
Design/methodology/approach
The domain is modeled using a coarse mesh that treats the laminated material as a bulk with averaged properties. The fine-structured behavior is recovered by introducing micro-shape functions in the ansatz space. One such method is analyzed to find further model restrictions.
Findings
By using a special reformulation, it is possible to eliminate the additional degrees of freedom introduced by the multiscale ansatz at the cost of an additional modeling error that decreases with the laminate thickness.
Originality/value
The paper gives a computationally more efficient approximate variant to a known multiscale method.