International Journal of Applied Electromagnetics and Mechanics - Volume 36, issue 3

Authors: Gürleyük, Sırrı Sunay | Öztürk, Ertan | Taşkın, Halit

Article Type: Research Article

Abstract: This paper presents the frequency domain analysis of a Tesla transformer system to obtain relationship between the frequency of an input square wave and the induced output voltage. This system has two coils coupled to each other via air. Resistances, inductances and parasitic capacitances make the coils a coupled second order dynamical system when the primary is fed by a square wave. Mathematical analysis bases on the transfer function written in frequency domain. The solution aims …to determine the frequencies in which the Tesla Transformer generates high output voltage. A comparison between the calculated and measured results shows the validity of the proposed approach. Show more

Keywords: Tesla Transformer, frequency analysis, coupled dynamical system, resonance

DOI: 10.3233/JAE-2011-1360

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 207-215, 2011

Authors: Bai, Yaxiang | LI, Xinjun | Sun, Yang | Shi, Hu

Article Type: Research Article

Abstract: The main objective pursued in this paper is to investigate the single layer drying behavior of fish slices experimentally in an electrohydrodynamic (EHD) dryer and also to perform mathematical modeling. Drying experiments of fish slices were studied at 10, 15, 20, 25 and 30°C, relative humidity of 30%, 40%, 50%, 60% and 70%, drying voltage from 5 kV to a maximum voltage of 50 kV in increments of 5 kV, the moisture content of fish slice …for constant sample thickness (8 mm), and the samples thicknesses from 2 mm to a maximum 16 mm in increments of 2 mm in a EHD dryer. Sample weight, drying rate were measured during drying and drying rate curves were obtained for each experimental data. The drying rate data were performed using seven different mathematical models to estimate a suitable model according to their correlation coefficient (R), determination coefficient (R^{2} ) and standard error (S), which were predicted by linear and non-linear regression analysis using SPSS computer program. It was deduced that the quadratic model were found to satisfactorily describe the drying rate of fish with the drying voltage, ambient temperature and drying time, respectively. However, the exponential model was the most suitable model to describe the drying rate of fish with the relative humidity, the moisture content and the thickness of fish slices, respectively. Show more

Keywords: Electrohydrodynamic (EHD) drying, fish, drying rate, mathematical modeling

DOI: 10.3233/JAE-2011-1361

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 217-228, 2011

Authors: Zhang, Chi | Tseng, King Jet | Nguyen, Trong Duy | Zhao, Guangzhou

Article Type: Research Article

Abstract: A compact flywheel energy storage system assisted by axial-flux partially-self-bearing permanent magnet motor has been proposed by the authors. The proposed machine combines axial magnetic bearing and motoring functionality into a single magnetic actuator, which not only spins the rotor-flywheel but also generates a levitation force to overcome the gravity. The mathematical model of the levitation force and stiffness of the active magnetic bearing are developed. The relationships between the stiffness and the key motor parameters …are studied. High stiffness can be achieved for the special motor design. The derived force model is validated by finite element analysis. The control system of the levitation force is designed and experimental setup is built. The test results prove the correctness of the mathematical analysis and feasibility of the designed control system. Show more

Keywords: Stiffness analysis, active magnetic bearing, levitation force control, flywheel energy storage system, partially-self-bearing motor

DOI: 10.3233/JAE-2011-1362

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 229-242, 2011

Authors: Peng, Chia-Mei | Chen, I-Fong

Article Type: Research Article

Abstract: Based on the Gaussian Filter Model (GFM), an equivalent circuit model that considers the effect of a finite-sized ground plane is presented to estimate the impedance bandwidth of typical printed monopole antenna geometry. The ground-plane is commonly regarded as a low impedance path for returning currents with constant potential across its area. In fact, the finite-size ground-plane of a PCB (Printed circuit board) is not a perfect-ground, it has significant reactance. Therefore, the result of printed …ground-plane versus monopole antenna should be regarded as an additional planar radiator rather than a normal ground-plane. The quantitative values of inductance and capacitance of the printed monopole antenna with coplanar ground-plane are addressed thoroughly in this paper. Measured and Ansoft HFSS simulation results are presented to confirm the results obtained using GFM. Show more

Keywords: Gaussian filter model, finite-sized ground plane, printed monopole antenna, finite-sized ground plane, returning currents

DOI: 10.3233/JAE-2011-1363

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 243-251, 2011

Authors: Torkaman, H. | Afjei, E. | Ravaud, R. | Lemarquand, G.

Article Type: Research Article

Abstract: The magnetic characteristics of a Switched Reluctance Motor (SRM) in normal and abnormal conditions are important in performance prediction and verification of the motor. In this paper, a novel view of air gap magnetic field analysis of SRM under rotor misalignment is presented. This analysis is based on a three-dimensional finite element method (FEM) to provide the precise fault diagnosis. This method is used to simulate reliable and precise model by considering the end effects as …well as axial fringing effects. The FE analysis are performed to obtain the static magnetic characteristics of SRM including flux linkages, terminal inductance and static torque profile under different rotor positions for varying degree of misalignments. To do so, Fourier analysis is carried out to study the variations of diagnosis index. Inductance waveforms were analyzed by FFT, and the concept of relative spectral coefficient from the FFT analysis is given as a fault diagnosis index, and its sensitivity to SRM misalignment fault is shown under different conditions. The obtained results present useful information with regard to the detection as well as the amount of misalignment fault. To the best knowledge of the authors, such an analysis has not been carried out previously. Show more

Keywords: Misalignment, axial eccentricity fault, non-uniform air gap, finite element method, fault diagnosis, switched reluctance motor

DOI: 10.3233/JAE-2011-1364

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 253-265, 2011

Authors: E, Shi-Ju | Cao, Jian-Bo

Article Type: Research Article

Abstract: The strain characteristics and power generation mechanism of electroactive acrylic elastomer (EAE) was studied by experiments based on theoretical analysis. The strain characteristics and generator mode theory fundamentals of EAE were discussed and studied. The mathematical model of EAE was established. A power conversion control system for EAE was designed. Electroactive strain values were measured for different pre-strain and driving voltages. The power generation process of EAE was tested under different influencing …factors. The experimental results show that the inflexion of electroactive strain was found for different pre-strain values, and the electroactive strain value increased with the augmentation of the driving voltage when the pre-strain level was below the inflexion, otherwise, the electroactive strain value decreased with the augmentation of the driving voltage. The hysteresis loop due to the viscoelasticity charateristic of EAE was measured. The energy generated as nearly incompressible elastomer layers increase in area and decrease in thickness when EAE stretched, and power generated when EAE relaxed. The voltage of power generation increased with the augmentation of the bias voltage, pre-strain level and compression speed. The experimental results accorded with analytical model and lay the foundation for actuators, generator and sensors of EAE. Show more

Keywords: Electroactive acrylic elastomer, strain characteristics, power generation, pre-strain

DOI: 10.3233/JAE-2011-1373

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 36, no. 3, pp. 267-278, 2011