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Leite J.V.,Federal University of Parana | Benabou A.,L2EP | Sadowski N.,GRUCAD EEL UFSC
IEEE Transactions on Magnetics | Year: 2010

Inrush currents have undesired effects on transformers when these ones are, for example, switched into service. Theses effects have to be taken into account when designing a transformer, what leads to a constraint on its magnetic core and size definition. This paper investigates the modeling of inrush currents in a three phase transformer under sinusoidal voltage operation conditions. The transformer core is modeled taking into account the magnetic hysteresis including the anisotropy. Therefore, a Jiles-Atherton vectorized model is used for the nonlinear core modeling. The key advantage of this vector model is its reluctivity tensor which is appropriated for the Finite Element calculations in vector potential formulation. A time-domain simulation was carried out and the results were compared with experimental data for the procedure validation. © 2006 IEEE. Source


Dular P.,University of Liege | Sabariego R.V.,University of Liege | Geuzaine C.,University of Liege | Ferreira Da Luz M.V.,GRUCAD EEL UFSC | And 2 more authors.
IEEE Transactions on Magnetics | Year: 2010

Model refinements of magnetic circuits are performed via a subdomain finite element method based on a perturbation technique. A complete problem is split into subproblems, some of lower dimensions, to allow a progression from 1-D to 3-D models. Its solution is then expressed as the sum of the subproblem solutions supported by different meshes. A convenient and robust correction procedure is proposed allowing independent overlapping meshes for both source and reaction fields, the latter being free of cancellation error in magnetic materials. The procedure simplifies both meshing and solving processes, and quantifies the gain given by each model refinement on both local fields and global quantities. © 2006 IEEE. Source


Wurtz F.,Grenoble Institute of Technology | Kuo-Peng P.,GRUCAD EEL UFSC | De Carvalho E.S.,GRUCAD EEL UFSC
Proceedings - 2012 20th International Conference on Electrical Machines, ICEM 2012 | Year: 2012

This paper suggests that Setting Optimization Problem is an important bottleneck in the practical use of optimization for design of electromagnetic devices. Setting Optimization Problem means in particular finding the right formulation of the constraints on the inputs and outputs of the optimization problem, and what is the right formulation of the objective functions. This problematic can certainly become a research topic in which concepts, methodologies and tools should be developed. As an example of this, this paper proposes a concept called the Imaginary Pareto Front (IPF) using itself the concept of Imaginary Machines (IM). We will show how it that can be used in order to check very quickly the constraints formulation of an optimization problem of electromagnetic devices, based on a continuous model in which some parameters are discrete. This will be illustrated on the design of a round-rotor synchronous generator. © 2012 IEEE. Source


Lacerda Ribas J.C.,Federal University of Parana | Lourenco E.M.,Federal University of Parana | Leite J.V.,GRUCAD EEL UFSC | Batistela N.J.,GRUCAD EEL UFSC
IEEE Transactions on Magnetics | Year: 2013

The ferroresonance phenomena in electrical power systems can cause very important quality and security problems. Although it has been extensively analyzed with different approaches since the birth of electrical systems, it still remains a challenge due the complexity of factors that can lead to the phenomenon. In this paper, a scalar Jiles-Atherton (JA) hysteresis model is applied to model a nonlinear ferromagnetic core allowing to analyze magnetic circuits, which can be in ferroresonant mode. It is used an inverse JA approach, which had originally the magnetic induction as its independent variable. The analysis here proposed applies a flux-current methodology to obtain a hysteresis behavior of a nonlinear inductor. © 1965-2012 IEEE. Source


Dular P.,University of Liege | Krahenbuhl L.,Ecole Centrale Lyon | Sabariego R.V.,University of Liege | Ferreira Da Luz M.V.,GRUCAD EEL UFSC | And 2 more authors.
IEEE Transactions on Magnetics | Year: 2012

Analyses of magnetic systems with position changes of both massive and stranded conductors are performed via a finite element subproblem method. A complete problem is split into subproblems associated with each conductor and the magnetic regions. Each complete solution is then expressed as the sum of subproblem solutions supported by different meshes. The subproblem procedure simplifies both meshing and solving processes, with no need of remeshing, and accurately quantifies the effect of the position changes of conductors on both local fields, e.g., skin and proximity effects, and global quantities, e.g., inductances and forces. Applications covering parameterized analyses on conductor positions to moving conductor systems can benefit from the developed approach. © 2012 IEEE. Source

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