The impedance boundary condition applied to the finite element method using the magnetic vector potential as state variable: a rigorous solution for high frequency axisymmetric problems

Sakellaris, J.; Meunier, G.; Raizer, Adroaldo; Darcherif, Abdelmoumen

doi:10.1109/20.124016

Cited by 13 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to obtain the impedance matrix, the system was simulated in Comsol Multiphysics. The 210 mm ∅ inductors are modelled as low losses disks with a uniform current density distributed in a single turn and the ferromagnetic loads as impedance boundary conditions [35]. The material properties for the loads are the same as those found in [14].…”

Section: A Finite Element Analysismentioning

confidence: 99%

Induction Heating of Two Magnetically Independent Loads With a Single Transmitter

Plumed

Lope

Acero

et al. 2022

IEEE Trans. Power Electron.

View full text Add to dashboard Cite

This paper introduces the design of a system capable to heat two magnetically independent ferromagnetic loads, placed on different horizontal planes, that uses a combination of induction heating and inductive coupling, called inductively coupled heating. The system uses a single primary inductor acting as transmitter to transfer power to a secondary inductor attached to the bottom, coupled load, which is connected electrically with a third inductor that heats the top, independent load. Since no more degrees of freedom are added, the delivered power to the second zone is entirely dependant on the system's geometry, materials and compensation capacitors. Therefore, the ratio of the delivered power to each of the zones becomes very relevant to the design. A finite element model is used to simulate the magnetic fields generated by inductor currents and calculate the impedance matrix. With the impedance, capacitor values and inductors' number of turns are selected with the objective of achieving a high power ratio between the top and bottom zone, as well as minimizing stress in the electronics. A prototype was built to validate the impedance results in the small signal regime first and then the full power regime was used to verify power and current simulations.

show abstract

Section: A Finite Element Analysismentioning

confidence: 99%

Induction Heating of Two Magnetically Independent Loads With a Single Transmitter

Plumed

Lope

Acero

et al. 2022

IEEE Trans. Power Electron.

View full text Add to dashboard Cite

show abstract

“…The calculation of the loss intensity on the tank wall is one of the tasks required in the design of the transformers. The surface impedance boundary condition (SIBC) is a technique usually used for characterising conductive parts of the transformer such as the tank wall [22]. It reduces substantially the computation time and the memory needed to obtain a solution of the transformer model.…”

Section: Modelling Of the Magnetic Shuntmentioning

confidence: 99%

Finite element and neural network approach for positioning a magnetic shunt on the tank wall of a transformer

Diaz-Chacon

Hernández

Arjona

2016

IET Electric Power Applications

View full text Add to dashboard Cite

Manufacturers reduce stray losses in transformers by using magnetic shunts. These losses may cause hot spots in metallic structural parts of transformers such as the tank wall and frames. The calculation of the reduction of the stray losses on the tank wall using magnetic shunts is a complex task. In this study, a method for determining the position of a magnetic shunt and reducing the stray losses on the tank wall of a transformer is presented. Feed-forward neural networks (FFNNs) and the finite element method are employed. The Latin hypercube sampling is used to achieve a reduced number of training cases. Afterwards, several two-dimensional finite-element axisymmetric models of a transformer are solved and used as training data for two FFNN models. A comparison with finite-element models is carried out to evaluate the proposed method. Finally, a case study is solved using this method. The approach offers an alternative method to predict and reduce the intensity of the stray losses on the tank wall of the transformer in a straightforward way.

show abstract

“…This condition implies surface field effects inside high conductivity materials establishing a relationship between the tangential electric and magnetic field in the boundaries, called impedance boundary condition Z c Ida, 1999, 2009). In this case, the magnetic vector potential A obeys the so-called Leontovich's boundary condition (Sakellaris et al, 1992;Di Rienzo et al, 2008) in the plane z ¼ z þ 1 , which is the boundary between the load and the air, and it is given by:…”

Section: Domestic Heating Systemsmentioning

confidence: 99%

An application of the impedance boundary condition for the design of coils used in domestic induction heating systems

Carretero

Lucía

Acero

et al. 2011

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

View full text Add to dashboard Cite

Purpose -The aim of this paper is to propose a design procedure based on the impedance boundary condition in order to simplify the design of inductors for domestic induction heating systems. Design/methodology/approach -An electromagnetic description of the inductor system is performed to substitute the effects of a component, named system load, for a mathematical condition, the so-called impedance boundary condition. This is suitable to be used in electromagnetic systems involving high conductive materials at medium frequencies, as it occurs in an induction heating system. Applying this approach, a simplified electrical model arises from the general system. Findings -A considerable reduction in the efforts devoted to design a coil for induction heating purposes is achieved, because the solution considering the variation of three physical parameters are projected to a one-dimensional space only depending on a single parameter named corrected penetration depth. This proposal assesses the working conditions of standard induction systems. Practical implications -This work is performed to achieve a better understanding of the fundamentals involved in the electromagnetic modeling of an induction heating system. The main goal is the definition of a better coil design process because it is probably the most time-consuming task in the construction of a complete induction system. Originality/value -In this paper, the so-called corrected penetration depth is defined. This single parameter allows explaining the influence of the physical parameter of the inductor load and the excitation frequency in the equivalent of the complete inductor system. The numerical results carried out considering the corrected penetration depth instead of the physical load properties have been validated experimentally. IntroductionDomestic induction heating systems are usually fed by a power electronic inverter working at a switching frequency ranging from 20 to 100 kHz, thus, the inductor system is viewed as an electrical equivalent impedance (Acero et al., 2010). The inductor system is made up of a coil placed between an electrical conductive medium, which is the load to be heated up by the system, and a magnetic insulator playing the role of flux concentrator (Acero et al., 2006) as can be seen in Figure 1. In order to improve the complete system performance, the inductor system equivalent impedance must be adapted to the power converter; consequently, efficient coil optimization is the goal of the system design process. However, such coil design process has to deal with several geometrical constraints and a wide load variety; therefore, roughly iterative simulation procedure is carried out with analytical (Hurley and Duffy, 1995) or numerical methods (Enokizono and Tanabe, 1995;Bay et al., 2003;Lavers, 2008). Such numerical simulations are based on the induction load modeling considering an homogeneous linear medium. Then, the load is characterized by means of its physical properties, for instance, electrical conductivity s and magnetic perme...

show abstract

The impedance boundary condition applied to the finite element method using the magnetic vector potential as state variable: a rigorous solution for high frequency axisymmetric problems

Cited by 13 publications

References 18 publications

Induction Heating of Two Magnetically Independent Loads With a Single Transmitter

Induction Heating of Two Magnetically Independent Loads With a Single Transmitter

Finite element and neural network approach for positioning a magnetic shunt on the tank wall of a transformer

An application of the impedance boundary condition for the design of coils used in domestic induction heating systems

Contact Info

Product

Resources

About