iosr-JEEE   Volume-8 ~ Issue-5

Abstract: An isolated buck–boost dc/dc converter for wide input-voltage range is proposed in this paper, and the full- bridge (FB) boost converter, being one of the typical topologies, is analyzed. Due to the existence of the resonant inductor (including the leakage inductor), the FB-boost converter can only adopt the two-edge-modulation (TEM) scheme with the FB cell being leading-edge modulated and the boost cell being trailing-edge modulated to minimize the inductor current ripple over the input- voltage range, and a phase-shift-control-scheme-based TEM with the use of the market available controller IC such as UC3895 is pro- posed, which realizes phase-shifted control for the FB cell to achieve zero-voltage switching. In order to improve the reliability and efficiency of the FB-boost converter, a three-mode dual-frequency control scheme is proposed, in which the FB-boost converter operates in boost, FB-boost and FB modes in low, medium and high input voltage regions, respectively, and for which the expression of the inductor current ripple is derived in this paper. As the input voltage in the FB-boost mode is close to the output voltage, the inductor current ripple in this mode is much smaller than that in the other modes, and the switching frequency of the boost cell in this mode can be lowered to one-(2N+1)th of the preset switching frequency to reduce the switching loss, and hence, to improve the efficiency. A 250–500 V input, 360 V output, and 6 kW rated power prototype is fabricated to verify the effectiveness of the design and control method. The average efficiency over the input-voltage range is 96.5%, and the highest efficiency attained is 97.2%.

[1] Xinbo Ruan, Chuan Yao, Xuehua Wang and Chi K. Tse YAO et al.: ―isolated buck–boost dc/dc converters suitable for wide input-voltage range,‖ , ieee transactions on power electronics, vol. 26, no. 9, september 2011 . [2] P. G. Barbosa, H. A. C. Braga, M. C. B. Rodrigues, and E. C. Teixeira, ―Boost current multilevel inverter and its application on single-phase grid connected photovoltaic systems,‖ IEEE Trans. Power Electron., vol. 21, no. 4, pp. 1116–1124, Jul. 2006. [3] T. Shimizu, O. Hashimoto, and G. Kimura, ―A novel high-performance utility-interactive photovoltaic inverter system,‖ IEEE Trans. Power Electron., vol. 18, no. 2, pp. 704–711, Mar. 2003. [4] M. J. V. Vazquez, J. M A. Marquez, and F. S. Manzano, ―A methodology for optimizing stand-alone PV-System sizing using parallel connected dc/dc converter,‖ IEEE Trans. Ind. Electron., vol. 55, no. 7, pp. 2664– 2673, Jul. 2008. [5] T. Kerekes, R, Teodorescu, M. Liserre, C. Klumpner, and M. Sumner, ―Evaluation of three-phase transformerless photovoltaic inverter topologies,‖ IEEE Trans. Power Electron., vol. 24, no. 9, pp. 2202–2211, Sep. 2009.

Abstract: In the matrix converter (MC) system to improve the input current quality with low harmonic components, as well as to reduce the input voltage distortion supplied to the MC by using input filters. The major consequence of the paper is about the inter harmonics appearing in the induction motor drive.. In this paper, we propose a new direct space vector modulation (DSVM) method to achieve the required displacement angle between the input voltage and input current of the MC. The paper illustrates the various inter harmonics elimination methods of SVM inverter fed drive and the associated drawbacks. The drawbacks are eliminated by using New DSVM method instead of SVM method in matrix converter fed induction motor drive. A new switching strategy is introduced based on the maximum compensated angle. Then, power factor compensation algorithms using the new DSVM method to achieve the maximum IPF. In which Compensation algorithm is subsequently proposed using a proportional–integral controller to overcome drawbacks presented in compensation algorithm of SVM method. Simulation and experimental results are shown to validate the effectiveness of the proposed compensation algorithms.

Keywords: Direct space vector modulation (DSVM) method, induction motor drive, inter-harmonics, input filter, matrix converter (MC).

[1] T.F.Podlesak, D.C.Katsis, P.W.Wheeler, J.C. Clare, L.Empringham, and M.Bland, "A 150-kVA vector-controlled matrix converter induction motor drive," IEEE Trans. Ind. Appl., vol. 41, no. 3, pp. 841–847, May/Jun. 2005. [2] C.Klumpner, P.Nielsen, I.Boldea, and F.Blaabjerg, "A new matrix converter motor (MCM) for industry applications," IEEE Trans. Ind. Electron., vol. 49, no. 2, pp. 325–335, Apr. 2002. [3] P.W. Wheeler, H.Zhang, and D.A. Grant, "A theoretical, and practical consideration of optimised input filter design for a low loss matrix converter," in Proc. 9th Int. Conf. Electromagn. Compat., Sep. 1994, pp. 138–142. [4] P.Wheeler and D.Grant, "Optimized input filter design, and low-loss switching techniques for a practical matrix converter," Proc. Inst. Elect. Eng.—Elect. Power Appl., vol. 144, no. 1, pp. 53–60, Jan. 1997. [5] D.Casadei, G.Serra, A.Tani, and L.Zarri, "Stability analysis of electrical drives fed by matrix converters," in Proc. IEEE ISIE, Jul. 2002, vol. 4, pp. 1108–1113.

Abstract: Switch Mode rectifiers for power-factor correction have gained considerable attention, due to the increasing demand for improved power quality. A new three-phase single-stage rectifier with Brushless DC motor is proposed in this paper. Each converter operates in the continuous conduction mode (CCM), which allows a high power factor and a small EMI filter. The outstanding features of the proposed rectifier are that it can produce input currents that do not have dead band regions and an output current that can be continuous when the converter is operating from maximum load to at least half of the load. Here we proposed full bridge converter with machine load condition system is validated through MATLAB/SIMULINK Platform.

Keywords: AC–DC power conversion, single-stage power factor correction (SSPFC), three-level converters, DC motor, Brushless DC motor.

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[5] J. M. Kwon, W. Y. Choi, and B. H. Kwon, "Single-stage quasi-resonant flyback converter for a cost-effective PDP sustain power module," IEEE Trans. Ind. Electron., vol. 58, no. 6, pp. 2372–2377, Jun. 2011.

Abstract: In this paper, the performance of the single quantum dots and couple quantum dots at intermediate band solar cells are investigated. Simulation results show that by increasing the distance between quantum dot overlap between the wave functions of the quantum dots is reduced and the intermediate bandwidth decreases. We found that an intermediate band has an inverse relation with efficiency. Keywords: Barrier width, Efficiency, Quantum dot intermediate band solar cell (QD-IBSCs) ، Quantum-dot width، Efficiency.

[1] P. F. Hamedan, A. Taghini, F. Yazdi, Z. Mirmoeini, "Study the Effect of Varying the Thickness of Intermediate Band on the Intermediate Band Solar Cells Efficiency" Energy Procedia, 14, 1496-1502, (2012).

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Abstract: This paper presents a systematic approach based on Eigen structure assignment to determine the mode shape and transient response of a STATCOM utilized as an exciter for induction generators (IG). A physical control scheme, including four control loops: ac voltage, dc voltage, ac active current and ac reactive current controllers, is pre-specified for the STATCOM. A synthetic algorithm is proposed to embed these physical control loops in the output feedback path. With appropriate oscillation mode design (Eigen structure) in each state variable, the STATCOM active current and reactive current will no longer be governed by the same mode but driven by new respective modes. The simulation and experimental results demonstrated that under various system disturbances, the proposed mode decoupling STATCOM is effective in regulating IG terminal voltage.

[1]. E. S. Abdin and W. Xu, "Control design and dynamic performance analysis of a wind turbine induction generator unit," IEEE
Trans. Energy Convers., vol. 15, no. 1, pp. 91–96, 2000.
[2]. R. Cardenas, R. Pena, G. Asher, and J. Clare, "Control strategies for enhanced power smoothing in wind energy systems using a
flywheel driven by a vector-controlled induction machine," IEEE Trans. Ind. Electron. vol. 48, no. 3, pp. 625–635, 2001.
[3]. G. O. Cimuca, C. Saudemont, B. Robyns, and M. M. Radulescu, "Control and performance evaluation of a flywheel energy-storage
system associated to a variable-speed wind generator," IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1074–1085, 2006.
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[5]. W. L. Chen, Y.-H. Lin, H.-S. Gau, and C.-H. Yu, "STATCOM controls for a self-excited induction generator feeding random
load," IEEE Trans. Power Del., vol. 23, no. 4, pp. 2207–2215, 2008.
[6]. W. L. Chen and Y. Y. Hsu, "Controller design for an induction generator driven by a variablespeed wind turbine," IEEE Trans.
Energy Convers., vol. 21, no. 3, pp. 625–635, 2006.
[7]. N. S. Wani and W. Z. Gandhare, "Voltage Recovery of Induction Generator using Indirect Torque Control Method", International
Journal of Electrical Engineering & Technology (IJEET), Volume 3, Issue 3, 2012, pp. 146 - 155, ISSN Print : 0976-6545, ISSN
Online: 0976-6553.

Abstract: In this research work, an UHF band L-shaped antenna based on microstrip-fed is proposed. In this antenna design T-shaped slot is embedded into L-shaped patch. The simulation and design of UHF band antenna operates at resonance frequency 0.897 GHz. The proposed antenna is composed of an L-shaped patch embedded with T-shaped slot and covers the UHF RFID band from 0.862-0.925 GHz. The fundamental parameters such as return loss, VSWR, radiation pattern and current distribution are obtained. A parametric study of proposed antenna has been carried out by varying some parameters. Simulation tool, based on method of moments has been used to analyze and optimize the antenna.

Keywords: L-shaped Patch, Microstrip line, Radio frequency identification (RFID), Transponders, Ultra High Frequency (UHF).

[1] www.extronics.com/intro-to-rfid.
[2] http://www.eecs.harvard.edu/cs199r/readings/rfid-article.pdf.
[3] http://www.ferroxcube.com/appl/info/RFID introduction.pdf.
[4] eprints.rclis.org/16848/2/RFID-SECURITY-Bibhuti.ppt.
[5] eprints.ibu.edu.ba/1058/1/vol1-no1-p53-71.pdf.
[6] Ming-Tao Zhang, Yong-Chang Jiao, Fu-Shun Zhang and Wu-Tu Wang, Design of antennas for RFID application, February 2009,Available from http://www.intechopen.com.

[7] Tran Minh Tuan, Design dual band microstrip antenna for RFID application, VNU Journal of Science, Natural Sciences and Technology 26 (2010) 276-280.

[8] Yi-Chieh Lee and Jwo-Shiun Sun, Dual-band dipole antenna for RFID tag applications, Proceedings of the 38th European Microwave Conference.

[9] G. Monti, L. Catarinucci, and L. Tarricone, Broad-Band Dipole for RFID applications, Progress In Electromagnetics Research C, Vol. 12, 163-172, 2010.

[10] Arun Kumar, Davinder Parkash, and M. V. Kartikeyan, Planar antennas for passive UHF RFID tags, Progress In Electromagnetics Research B, Vol. 19, 305-327, 2010.

Abstract: The state estimator processes the information available and produces the best possible estimate of the true state of the system. .It is a digital processing scheme which provides a real-time data base for many of the central control and dispatch functions in a power system. The real-time data are processed by state estimator, a computer program which calculates voltage magnitudes and relative phase angles of the system buses. While the state estimator gives result similar to those available from conventional power-flow program, the input data and calculation procedure are quite different. Bus injections along with line flow measurements form the measurement vector in the state estimator in order to evaluate the final states of the power system. Test results without and with measurement noises have been presented. Estimator is also capable of identifying the bad data present in the measurement vector.

Keywords: Data Acquisition System, Dynamic State, Estimator and Tracking State.

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[9] Roberto M¶³nguez Department of Mathematics, University of Castilla-La Mancha Antonio J. Conejo Department of Electrical
Engineering University of Castilla-La Mancha. Ali S. Hadi Department of Mathematics American University in Cairo, Non
Gaussian State Estimation in Power Systems, International Conference on Mathematical and Statistical Modeling in Honor of
Enrique Castillo, June 28-30, 2006.
[10] Vassilis Kekatos, Member, IEEE, and Georgios B. Giannakis, Fellow, IEEE "Distributed Robust Power System State Estimation
IEEE transactions on power systems", vol. 28, no. 2, May 2013.