International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Kawaguchi, Hideki

Article Type: Research Article

Abstract: This paper proposes a scattered field formulation of the finite-difference time domain method (S-FDTD) combining with a time-domain electric field integral equation (TD-EFIE) based on surface equivalence theorem. The scattered field formulation enables us to reduce computation cost effectively for the case that scatterers are located at a far distance from field sources of electromagnetic wave since we need to calculate the scattered field component only on the region in the vicinity of the scatterers. Then it is required for the use of the scattered field formulation that the field source for the incident field component has to be expressed …by any analytical solutions such as a point dipole source, plane wave, and so on. In this work, the scattered field formulation of the FDTD method is applied to cases that there are no analytical expressions of the field sources, in which the field source contains conductors such as antennas, combining with the TD-EFIE on a virtual surface which encloses the field sources. Then, it is known that calculation of the TD-EFIE itself is time consuming. This paper considers speed-up of the S-FDTD simulation based on the TD-EFIE using a spherical harmonic expansion of Green’s function of Helmholtz equation, additionally. Show more

Keywords: Finite-difference time-domain method, microwave propagation, scattered field formulation, surface equivalence theorem, time-domain electric field integral equation, spherical harmonic expansion, Green’s function of Helmholtz equation

DOI: 10.3233/JAE-190164

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-9, 2020

Authors: Di Barba, Paolo | Dughiero, Fabrizio | Forzan, Michele | Sieni, Elisabetta

Article Type: Editorial

DOI: 10.3233/JAE-209100

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-2, 2020

Authors: Lucia, S. | Navarro, D. | Sarnago, H. | Lucia, O.

Article Type: Research Article

Abstract: Modern induction heating systems involve usually many non-linear systems with different constraints, making difficult implementing classical controllers. In this context, model predictive control arises as a powerful technique able to provide high performance controllers with advanced functionalities. This paper will discuss the benefits of this control technique for induction heating systems and will provide an example of application for domestic systems. As a conclusion, MPC will help powering future induction heating systems with improved control capabilities and performance.

Keywords: Induction heating, model predictive control, optimization, power electronics, resonant power conversion

DOI: 10.3233/JAE-209104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-8, 2020

Authors: Pérez-Tarragona, Mario | Sarnago, Héctor | Lucía, Óscar | Burdío, José M.

Article Type: Research Article

Abstract: Flexible cooking surfaces, eg. fully active surfaces, have gained lately an increasing importance in the domestic induction heating. Multi-inverter structures are a cost-efficient solution to develop this technology. However, they add control restrictions that can be solved with a power factor corrector (PFC) stage as proposed in this work. The proposed converter and modulation strategy work with zero voltage switching (ZVS), decreasing the switching losses, enabling a higher working frequency and, therefore, decreasing the magnetic devices size. The bus voltage is controllable and can be increased, easing the load power control and decreasing current through load and inverter and, …so, the power losses. Besides, the switching frequency is constant in the mains cycle and can be modified to synchronize the load inverter and the PFC stage avoiding intermodulation noise. A 3.6 kW prototype has been implemented fulfilling the EMC requirements. The experimental waveforms and efficiency have been measured to prove the feasibility of this proposal. Show more

Keywords: Power factor corrector, resonant power conversion, zero voltage switching, home appliances, induction heating

DOI: 10.3233/JAE-209114

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-7, 2020

Authors: Goldsteins, L. | Ziks, A. | Sennikovs, J. | Liepins, V. | Geidmanis, D. | Sondors, P.

Article Type: Research Article

Abstract: The paper aims to optimize niobium reactor electrical heating in deep vacuum conditions towards to original process of titanium production using vapour-phase reduction. The study aims to explore optimal electrical heating power of tungsten heater surrounded by molybdenum reflectors to reach temperature of niobium reactor up to 1200 [C] located in the vacuum chamber. Numerical modelling approach has been used to solve heat radiation problem using OpenFOAM solver coupled with Hemicube algorithm in a 3D, transient, parametric study varying electrical power and unknown emissivity coefficient of reflectors. The experiment in the same power range has been conducted obtaining temperature measurements …of 8 thermocouples across the system. The paper provides a comparison and analysis of temperature distribution in the system obtained by numerical and experimental studies, which allowed to calibrate unknown emissivity coefficient of reflectors. The study also revealed necessity of systems geometry modification to achieve desired temperature profile. Show more

Keywords: Electrical heating, high temperature, niobium reactor, vapour-phase reduction

DOI: 10.3233/JAE-209105

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-8, 2020

Authors: Alpini, F. | Cesano, M. | Ciscato, D. | Dalle Nogare, G. | Natale, L.

Article Type: Research Article

Abstract: Temperature is a key parameter in the industrial forging process. Induction heating is a fast, efficient and easily controllable system to have a uniform and controlled thermal profile before forging. The possibility to have a finer control over the temperature management leads to the improvement in process, a better product quality level, and lower maintenance cost. In this paper, the pyrometer noise and unstable signal is filtered and corrected using a Kalman filter based on a numerical electro-thermal model to obtain a reliable signal for the process management.

Keywords: Industrial process control, Kalman filter, induction heating, induction forge, numerical model, Dyna Forge Zone

DOI: 10.3233/JAE-209123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-6, 2020

Authors: Birjukovs, Mihails | Dzelme, Valters | Jakovics, Andris | Thomsen, Knud | Trtik, Pavel

Article Type: Research Article

Abstract: This paper presents detailed results of neutron imaging of argon bubble flows in a rectangular liquid gallium vessel with and without the application of external horizontal magnetic field. The developed image processing algorithm is presented and its capability to extract physical information from images of low signal-to-noise ratio is demonstrated. Bubble parameters, velocity components, trajectories and relevant statistics were computed and analysed. A simpler version of the code was applied to the output of computational fluid dynamics simulations that reproduced the experiment. This work serves to further validate the neutron radiography as a suitable method for monitoring gas bubble flow …in liquid metals, as well as to outline procedures that might help others to extract data from neutron radiography images with a low signal-to-noise ratio resulting from high frame rate acquisitions required to resolve rapid bubble motion. Show more

Keywords: High frame rate neutron imaging, magnetohydrodynamics (MHD), two-phase flow, image processing, computational fluid dynamics (CFD)

DOI: 10.3233/JAE-209116

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-7, 2020

Authors: Khrenkov, N. | Strupinskiy, M.

Article Type: Research Article

Abstract: In the paper, the dependence of the current characteristics of self-regulating heating cables on the environmental conditions is investigated. A method is proposed to determine the allowable length of a heating section depending on the environmental conditions and parameters of automatic circuit breaker used.

Keywords: Self-regulating cables, current characteristics, temperature

DOI: 10.3233/JAE-209122

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2020

Authors: Vaishnava, Prem P. | Goldstein, Robert C.

Article Type: Research Article

Abstract: Many induction heating coils use soft magnetic composite materials (SMC) to improve induction heating system performance. In demanding induction heating applications, the core loss in the soft magnetic composite material is one of the critical factors in predicting the reliability of the induction coil using computer modelling. In this paper we have used calorimetry method for experimentally determining core losses in SMCs up to ≈1 T magnetic flux densities at a frequency near 150 kHz. This paper contains a discussion on the limitations of current methods for calculating core losses. To address these limitations, a new method for calculating core losses is …presented. The results of the core loss measurement did not fit well with traditional core loss models over the full range of magnetic flux densities. A discussion on the different models and a hypothesis for the source of the variation from the models is presented. Show more

Keywords: Soft magnetic composite (SMC), iron core losses, Steinmetz equation, Bertotti’s equation

DOI: 10.3233/JAE-209109

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-8, 2020

Authors: López-Alonso, B. | Sarnago, H. | Burdío, J.M. | Lucía, O.

Article Type: Research Article

Abstract: Nowadays, several applications of electroporation have been adopted in cancer therapy with promising results that have boosted research interest. To develop new treatment options, the development of electroporation models and measurement method in order to study the real distribution of the electric field potential are needed. Nowadays, current trends in electroporation techniques suggest the use of more powerful pulse generators that enables the treatment of larger tissue volumes. However, new challenges arise regarding the modeling of the electroporation process in large tissue volumes as well as the potential thermal effects when large amounts of energy are used. The aim of …this paper is to propose a finite element analysis (FEA) based model using COMSOL of the irreversible electroporation process considering both electrical and thermal effects, and to validate it through in-vivo experimentation. Moreover, we propose a methodology for measuring the electrical potential in different points of a biological tissue during the application of a train of pulses to measure the distribution of the electric field inside the tissue. For this application, needle-based electrodes have been developed to achieve the least invasive measurement possible. These tools are aimed to improve the application of the electroporation treatment by reducing its side effects. Show more

Keywords: Electroporation, finite elements analysis, electric field potential measure

DOI: 10.3233/JAE-209118

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-10, 2020