A Practical Modeling Method for Eddy-Current Losses Computation in Laminated Magnetic Cores

Abstract. This paper presents comparative results of an electromagnetic study performed in two different wound core transformer configurations in order to know the best configuration that reduce excitation current and core losses. The results show that octagonal wound-core (OWC) reduces the excitation current and eddy-current losses with respect conventional-wound core (CWC). The results were obtained applying 2D and 3D FEM simulations, taking into account the non-linear properties of the core. In the last part of this paper, several grades of grain oriented electrical steels and the combination of them are analyzed to find the best mixing percentage to reduce eddy-current losses and excitation current.

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“…An important parameter in eddy current calculation is the skin depth δ. The distribution of the dissipated power, can be calculated from [5]:…”

Section: Electromagnetic Analysis and Simulationsmentioning

confidence: 99%

Electromagnetic Analysis and Comparison of Conventional-Wound Cores and Octagonal-Wound Cores of Distribution Transformers

Hernandez

Cañedo

Olivares-Galván

et al. 2010

MSF

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“…According to the approach presented in [33] and [34], it is possible to model a laminated core domain by means of a single solid domain assigning to the domain a proper value of the electrical resistivity. In particular, the model developed in [33] and [34] is based on an equivalent resistivity obtained multiplying the material electrical resistivity by the squared number of sheets, as reported in (1).…”

Section: Modeling and Simulation Issuesmentioning

confidence: 99%

“…In particular, the model developed in [33] and [34] is based on an equivalent resistivity obtained multiplying the material electrical resistivity by the squared number of sheets, as reported in (1).…”

Section: Modeling and Simulation Issuesmentioning

confidence: 99%

Impact of the rotor back-iron resistivity on the rotor eddy-current losses in fractional-slot concentrated windings PM machines

Cavagnino

Lazzari

Miotto

et al. 2011

2011 IEEE Energy Conversion Congress and Exposition

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It is well known that in fractional-slot concentrated windings the eddy-current losses in the permanent magnets can be relevant and, for this reason, they must be evaluated in the machine design procedure. The paper investigates the influence of the rotor back-iron resistivity on the rotor eddy-current losses in this machine typology. In particular, a external rotor annulus shape PM machine with fractional-slot non-overlapping concentrated windings is considered. The machine is a scaled representative prototype of starters/generators embedded in aircraft engines. Both the rotor back-iron and permanent magnet eddy-currents are simultaneously considered by means of bidimensional transient FEM simulations, including effects of stator slotting, rotor motion and material saturation. The analysis is conducted increasing the rotor back-iron resistivity from an ideal situation of a high-conducting material up to the opposite ideal condition of a non-conducting material. Adjusting the rotor backiron resistivity, the space MMF harmonic components influence on the machine torque is qualitatively investigated and discussed too.

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“…The distribution of the dissipated power can be calculated from [16]: (2) where represents the number of elements, is a diagonal tensor of resistivity of the GOSS, is the eddy-current density vector of the element , and is the volume of the element . Eddy-current density is given by (3) where represents the element shape functions for the vector potential .…”

Section: Electromagnetic Analysis and Simulationsmentioning

confidence: 99%

A Novel Octagonal Wound Core for Distribution Transformers Validated by Electromagnetic Field Analysis and Comparison With Conventional Wound Core

et al. 2010

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This paper analyzes a novel configuration of transformer core, called octagonal wound core (OWC), and shows the minimization of the excitation current and the reduction of the eddy-current losses. The OWC is compared with the conventional wound core (CWC) configuration. The comparison is based on two-dimensional and three-dimensional finite-element method (FEM) simulations, taking into account the nonlinear properties of the magnetic material of the core. The results show that the OWC reduces the excitation current and the eddy-current losses when compared with CWC. Moreover, several combinations of grades of the grain-oriented silicon steel (GOSS) were investigated so as to further reduce the eddy-current losses and the excitation current.

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A Practical Modeling Method for Eddy-Current Losses Computation in Laminated Magnetic Cores

Cited by 11 publications

References 5 publications

Electromagnetic Analysis and Comparison of Conventional-Wound Cores and Octagonal-Wound Cores of Distribution Transformers

Electromagnetic Analysis and Comparison of Conventional-Wound Cores and Octagonal-Wound Cores of Distribution Transformers

Impact of the rotor back-iron resistivity on the rotor eddy-current losses in fractional-slot concentrated windings PM machines

A Novel Octagonal Wound Core for Distribution Transformers Validated by Electromagnetic Field Analysis and Comparison With Conventional Wound Core

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