International Journal of Applied Electromagnetics and Mechanics - Volume 19, issue 1-4

Authors: Schulte, Stephan | Schlensok, Christoph | Henneberger, Gerhard

Article Type: Research Article

Abstract: This paper describes an easy to handle analytical method for the computation of the rms current stress on the DC-link capacitor of PWM converters. Both the PWM and the square wave mode (SWM) operation powering rotating field machines e.g. induction- or synchronous machines are considered. The rms current stress on the DC-link capacitor mainly affects its working temperature. Therefore it is a significant factor for the estimation of its duty cycle. On the one hand the …value of the DC-link capacitor current is determined by the amplitude and the phase angle of the inverter output phase current, deriving from the actual load. On the other hand it is influenced by the modulation depth and the phase number of the arrangement as well. The results achieved with the simple analytical model match very well with results of complex simulation models. The equivalent computing time compared to common simulation tools at reasonable time steps is reduced by more than a factor of thousand. Show more

DOI: 10.3233/JAE-2004-615

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 497-502, 2004

Authors: Cardelli, Ermanno | Faba, Antonio

Article Type: Research Article

Abstract: In this work we will present some remarks about the numerical analysis of non destructive testing for thin cracks detection in metallic plates. In particular this paper show the solution of a coupled electrical circuit – magnetic field problem using a finite element approximation scheme. This procedure is used in order to increase the sensibility of detector system. A comparison between experimental and numerical results is also presented.

DOI: 10.3233/JAE-2004-616

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 503-507, 2004

Authors: Popa, Nicolae Calin | Siblini, Ali | Jorat, Luc

Article Type: Research Article

Abstract: The volumetric flow meter for gases with magnetic fluid is built using a sensing unit (without moving solid mechanical components but exploiting the properties of magnetic fluids) and an electronic measuring system. The sensing unit consists of two sensors, one for differential pressure in gases (equipped with a laminar flow-measuring tube) and another for acceleration or inclination angle. Starting from some technical characteristics (of these sensing units) obtained by a numerical simulation method (or by an …analytical one), the paper presents the possibility of using this kind of transducers in a N+1 flow meters network for gases. Every N flow meters of closed range are supervised by another flow meter of higher range. This structure can warn (by software) about any problem (e.g. gases leakage) in the network. Show more

Keywords: ferrofluids, transducers, numerical simulation, aerodynamics

DOI: 10.3233/JAE-2004-617

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 509-514, 2004

Authors: Luo, Ping | Yang, Shiyou | Ni, Guangzheng | Ni, Peihong | Liu, Z.J.

Article Type: Research Article

Abstract: A fast and efficient global optimal design technique based on the combination of the Response Surface Model (RSM) using improved Radial Basis Functions (RBFs) and the tabu search method is proposed. Computer simulation results on two different design problems are presented to demonstrate the efficiency and robustness as well as the advantage of the proposed algorithm for solving computationally heavy optimal design problems.

Keywords: response surface model, tabu search method, global optimal method

DOI: 10.3233/JAE-2004-618

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 515-520, 2004

Authors: Prémel, Denis | Pichenot, Grégoire | Sollier, Thierry

Article Type: Research Article

Abstract: A theoretical and numerical model is developed for the computation of Eddy Current (EC) signals provided by a differential type probe used for tubing inspection. The main application of interest is to make simulated experiments for studying the perturbations affecting the EC signal such as the variations of the eccentricity and the probe wobble. 3D flaws are introduced by a variation in the local distribution of the conductivity. The forward problem is handled by using a …dyadic Green's function approach. Typical impedance plane trajectories obtained with a differential probe are given. Show more

Keywords: non destructive evaluation, forward problem, probe eccentricity

DOI: 10.3233/JAE-2004-619

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 521-525, 2004

Authors: Chen, Zhenmao | Yusa, Noritaka | Miya, Kenzo | Tanahashi, Akira | Sakai, Kazuo | Chigusa, Naoki

Article Type: Research Article

Abstract: In this paper an advanced MFLT method is proposed for detecting far side defects in a welding part of a thick stainless steel plate based on the measurement of the remanent magnetic field. The method consists of a double yoke magnetizer, high frequency demagnetization procedure and an inverse analysis scheme. The performance of the proposed method is investigated through numerical simulations and experiments. The results show that a far side defect in a plate as thick …as 20 mm is possibly to be detected by using the proposed strategy. Show more

Keywords: magnetic flux leakage method, high frequency demagnetization, inverse problem, remanent magnetization

DOI: 10.3233/JAE-2004-620

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 527-532, 2004

Authors: Woronowicz, Konrad | Palka, Richard

Article Type: Research Article

Abstract: This paper describes a solution to the control problems that can be associated with the application of the linear induction motor (LIM) in urban transportation. In order to meet the principle objective of LIM control – the peak thrust tracking – a new compensation technique is presented. The control system has additionally been verified by use of the appropriate finite element field calculations of the LIM and measurements done on the test machine.

Keywords: linear induction drives, vector control, compensation techniques

DOI: 10.3233/JAE-2004-621

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 533-536, 2004

Authors: Bensetti, Mohamed | Bihan, Yann Le | Marchand, Claude | Pavo, Jozsef

Article Type: Research Article

Abstract: In this paper, the eddy current nondestructive evaluation method is used to determine the electrical conductivity, the thickness and the size of a deposit located on the reverse side of a tested specimen. The eddy current probe consists in a coil. The impedance of the coil is calculated by a boundary integral method. The inverse problem is solved by combining a neural network and an iterative resolution.

Keywords: neural network, eddy current, nondestructive evaluation, inverse problem

DOI: 10.3233/JAE-2004-622

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 537-540, 2004

Authors: Tanaka, Yoshikazu | Furuki, Syuuji | Shintaku, Eiji | Fujimoto, Yukio

Article Type: Research Article

Abstract: This paper describes the resonance characteristics with the magnetic damping on higher vibration modes. Using the frequency response function obtained from the symmetric matrix equation of the magnetically damped vibration, the differences between the characteristic of the magnetic damping and those of the proportional viscous damping are discussed. Since the downward tendency of amplitude with the magnetic damping is different from that of the proportional viscous damping, it is shown that to perform analyses with …considering magnetic damping is important for design activity of such structures. Show more

Keywords: resonance characteristics, magnetic damping, frequency response function, higher vibration modes

DOI: 10.3233/JAE-2004-623

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 541-544, 2004

Authors: Adane, Yacine | Wong, Man-Faï | Gati, Azeddine | Dale, Christian | Wiart, Joe | Hanna, Victor Fouad

Article Type: Research Article

Abstract: A new approach based on the superposition of sub-antennas radiating characteristics is used to get accurate models of real base station antennas. The sub-antennas are modelled by solving an over determined matrix equation using a least squares procedure. This process allows determining the gain of the sub-antennas while their fields are calculated analytically. The superposition of the fields of the sub-antennas gives the field of the studied base station antenna, which can then be used to …assess the human exposure to the electromagnetic fields emitted by the base station antennas of mobile networks. Show more

DOI: 10.3233/JAE-2004-624

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 545-549, 2004