iosr-JEEE   Volume-4 ~ Issue-5

Abstract: Digital control technique is a technique for high frequency switching mode power supply (SMPS). Being widely used in the new generation portable systems, the regulation requirement for high frequency integrated DC-DC switching mode power supply becomes more and more demanding in industry, at very high frequency beyond 10 Mega Hertz range. Analysis and experimental study of buck converter is presented to achieve desired output voltage. The SMPS are emerging in terms of higher dynamic response performances, less output ripple, smaller size and weight. The sliding mode controller is associated with a digital pulse width modulation (DPWM) block to operate at high switching frequency. Sliding mode control (SMC) can reduce the voltage ripple voltage ripple of SMPS. Sliding mode controller will be used by means of analog to digital conversion (ADC) and Digital pulse width modulation (DPWM).

Keywords- Analog to Digital converter(ADC), Digital pulse width modulation(DPWM), Sliding mode control

[1] B. Patella, A. Prodic, A. Zirger, and D. Maksimovi´c, "High-frequencydigital PWM controller IC for DC-DC converters," IEEE Trans. Power Electron., vol. 18, no. 1, pp. 438–446, January 2003.
[2] J. Xiao, A. Peterchev, J. Zhang, and S. Sanders, "An ultra -low-powerdigitally-controlled buck converter IC for cellular phone
applications," in Proc. 19th Annu. IEEE Appl. Power Electron. Conf. Expo. (APEC 2004), vol. 1, pp. 383–391.
[3] Z. Luki´c, N. Rahman, and A. Prodi´c, "Multibit Δ–Σ PWM digital controller IC for DC–DC converters operating at switching
frequencies beyond 10 MHz," IEEE Trans. Power Electron., vol. 22, no. 5, pp. 1693–1707, September 2007.
[4] A. Peterchev and S. Sanders, "Quantization resolution and limit cyclingin digitally controlled PWM converters," IEEE Trans. Power
Electron.,vol. 18, no. 1, pp. 301–308, January 2003.
[5] M. Batarseh, W. Al Hoor, L. Huang, C. Iannello, and I. Batarseh, "Segmented digital clock manager -FPGA based digital pulse width
modulator technique," in Proc. 39th IEEE Annu. Power Electron. Spec. Conf. (PESC 2008), June, pp. 3036–3042.
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World Congr.Comput. Intell., June 1994, vol. 3, pp. 1654–1659.
[7] S. Tan, Y. Lai, and C. Tse, "General design issues of sliding-mode controllers in DC–DC converters," IEEE Trans. Ind. Electron., vol.
55, no. 3, pp. 1160–1174, March 2008.
[8] V. Utkin, Sliding Mode and Their Applications in Variable Structure Systems. Moscow, Russia: Mir, 1978.
[9] M. Castilla, L. Vicuna, M. Lopez, O. Lopez, and J. Matas, "On the designof sliding mode control schemes for quantum resonant
converters," IEEETrans. Power Electron., vol. 15, no. 6, pp. 960–973, November 2000.
[10] S. Tan, Y. Lai, and C. Tse, "Indirect sliding mode control of power converters via double integral sliding surface," IEEE Trans. Power Electron.vol. 23, no. 2, pp. 600–611, March 2008.

Abstract: This paper focuses on the power electronics used in the renewable energy systems especially in the photovoltaic applications. In recent years, interest in natural energy has grown in response to increased concern for the environment. Due to the limitations in the energy available from conventional sources, worldwide attention is being focused on renewable sources of energy. Especially, the energy obtained from solar arrays, becomes more and more important. In grid connected applications, a modular micro-inverter integrated with each photovoltaic (PV) panel can reduce the overall system cost and increase the system reliability and MPPT efficiency. In order to make the PV generation system more flexible and expandable, the backstage power circuit is composed of a high step-up converter and a pulse width-modulation (PWM) inverter. The traditional voltage-fed-full-bridge DC-DC converter suffers high cost, low transformer efficiency and discontinuous input current problems. A current-fed-half-bridge converter topology is utilized herewith continuous input current current, low cost and high efficiency features. A 210 W single-phase PV microinverter system with galvanic isolation is presented. By integrating microinverter to each PV panel, localized MPPT of each individual PV panel can be achieved, thus loading to fast tracking speed and higher system efficiency.

Keywords - PV array, boost-half-bridge, grid-connected photovoltaic (PV) system, maximum power point tracking, repetitive current control.

[1] Yeong-Chau Kuo, Tsorng-Juu Liang and Jiann-Fuh Chen, "Novel Maximum-Power-Point-Tracking Controller for Photovoltaic
Energy Conversion System, "IEEE Transactions on Industrial Electronics, vol.48, no.3, June 2001.
[2] J. Kishore Kumar, V. Lakshmi Devi and H. Rajesh Kumar," Design and Analysis of a Grid-Connected Photovoltaic Power System,"
International Journal of Power System Operation and Energy Management, ISSN (PRINT): 2231 – 4407, Volume-1, Issue-4, 2012.
[3] Billy M. Ho and Henry Shu-Hung Chung, "An Integrated Inverter with Maximum Power Tracking for Grid-Connected PV Systems," IEEE Transactions on Power Electronics, vol. 20, no.4, July 2005.
[4] Eftichios Koutroulis and Frede Blaabjerg," Methods for Optimal Design of Grid Connected PV Inverters," International Journal of
Renewable Energy Research, Vol.1, No.2, May 2011.
[5] Prashant. V. Thakre, V. M. Deshmkh, and Saroj Rangnekar," Performance Analysis of Photovoltaic PWM Inverter with Boost
Converter for Different Carrier Frequencies Using MATLAB," IACSIT International Journal of Engineering and Technology, Vol. 4,
No. 3, June 2012.
[6] Suman Dwari and Leila Parsa," An Efficient High-Step-Up Interleaved DC–DC Converter with a Common Active Clamp,"
IEEETransactions on Industrial Electronics, vol.26, no.1, January 2011.
[7] Tamer T.N. Khatib, Azah Mohamed and Nowshad Amin, "A New Controller Scheme for Photovoltaics Power Generation Systems," European Journal of Scientific Research, ISSN 1450-216X, Vol.33 No.3 (2009), pp.515-524.
[8] CH.Sravan and D.Narasimha Rao, "An Interleaved Boost Converter with Zero-Voltage Transition for Grid Connected PV System,"
International Journal of Emerging trends in Engineering and Development, ISSN 2249-6149 Issue 2, Vol.2, March-2012.
[9] Soeren Baekhoej Kjaer, John K. Pedersen and Frede Blaabjerg, "A Review of Single-Phase Grid-Connected Inverters for
Photovoltaic Modules," IEEE Transactions on Industrial Electronics, vol.41, no.5, September 2005.
[10] Nicola Femia, Giovanni Petrone and Giovanni Spagnuolo, "A Technique for Improving P&O MPPT Performances of Double-Stage
Grid-Connected Photovoltaic Systems," IEEE Transactions on Industrial Electronics, vol.56

Abstract: The efficiency of a diagnosis system depends on the relevance of the information it can be retrieve from the diagnosed plant. The diagnostic system detects, localizes and assesses the damage which may be in the form of delimitation, crack, buckling etc. Optical sensors like Fiber Bragg Grating sensor may be used to determine the strain, temperature and other diagnostic parameters. In real world structural applications the numbers of sensors available are limited which thus requires the need for an efficient sensor optimization algorithm. This paper describes an approach in which a genetic algorithm is used to determine the optimum sensor positions for a diagnostic system. The fundamental issue regarding any diagnostic systems is which data should be processed and how the sensors should be placed. GAs being general purpose optimization algorithms is extremely suitable for such sensor placement problems. In this work the GA is tested using fitness function based on an assigned weight matrix and is developed while setting up the problem to simulate the presence of an effective damage detection system. For initial testing of the GA, we consider that there exists a neural network based identification system for a plate with 20 potential sensors locations.

Keywords: Diagnostic system, Fiber Bragg grating sensors, Genetic algorithm.

[1] Udwadia F E and Garba J A 1985 Optimal sensor locations for structural identification Proc. JPL Workgroup on Identification
and Control of Flexible Space Structures (San Diego, CA) pp 247–61
[2] Lim T W 1991 Sensor placement for on-orbit modal identification Proc. 32nd Conf. AIAA/ASME/ASCE/AHS/ASC Structures,
Structural Dynamics, and Materials (Reston, VA: American Institute of Aeronautics and Astronautics)
[3] Kammer D C 1991 Sensor placement for on orbit modal identification and correlation of large space structures AIAA J. Guid.
Control Dyn. 14 251–9
[4] Hemez F M and Farhat C 1994 An energy based optimum sensor placement criterion and its application to structure damage
detection Proc. 12th Conf. on Int. Modal Analysis (Honolulu, HI: Society of Experimental Mechanics) pp 1568–75
[5] Miller R E 1998 Optimal sensor placement via Gaussian quadrature Appl. Math. Comput. 97 71–97
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Chapter C5.2, 1997.
[7] K. Worden, A. P. Burrows, "Optimal sensor placement for fault detection ", Engineering Structures, Vol. 23, pp. 885-901, 2001.

Abstract: In this paper, we present the concept of transmitting power without using wires i.e., transmitting power as microwaves from one place to another is in order to reduce the cost, transmission and distribution losses. This concept is known as Microwave Power transmission (MPT). We also discussed the technological developments in Wireless Power Transmission (WPT) which are required for the improment .The components which are requiredfor the development of Microwave Power transmission(MPT)are also mentioned along with the performance when they are connected to various devices at different frequency levels . The advantages, disadvantages, biological impacts and applications of WPT are also presented.

Keywords: Microwave Power transmission (MPT), Nikola Tesla,Rectenna,Solar Power Satellites (SPS),Wireless Power transmission (WPT).l

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Abstract: Over the years, access control systems have become more and more sophisticated and several security measures have been employed to combat the menace of insecurity of lives and property. This is done by preventing unauthorized entrance into buildings through entrance doors using conventional and electronic locks, discrete access code, and biometric methods such as the finger prints, thumb prints, the iris and facial recognition. In this paper, a prototyped door security system is designed to allow a privileged user to access a secure keyless door where valid smart card authentication guarantees an entry. The model consists of hardware module and software which provides a functionality to allow the door to be controlled through the authentication of smart card by the microcontroller unit.

[1] Chika, E.O., and Okechukwu, O.S (2010): "Access Card Door". University of Port Harcourt, R ivers State.
[2] Hurley, Edward (2002): "Smart cards have their advantages over passwords". Online available: http://searchsecurity.techtarget.com.
Date Accessed: 19/12/ 2012.
[3] Kenneth, Ayala (1991): The 8051 Microcontroller, West Publishing Company, New York.
[4] Oke, A.O., O.M. Olaniyi, O.T. Arulogun, and O.M. Olaniyan (2009): "Development of a Microcontroller -Controlled Security Door System". Pacific Journal of Science and Technology. 10(2):398-403.
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Abstract: Solar energy is rapidly becoming an alternative means of electricity source. Fossil fuels are seriously depleting, thus the need for alternative energy source is a necessity. To make effective use of solar energy, its efficiency must be maximized. A feasible approach to maximizing the power output of solar array is by sun tracking. This paper therefore presents the design and construction of a solar tracking system that position the solar PV panel in proper orientation with the sun so as to always receive direct radiation. The prototype is designed around a programmed microcontroller which controls the system by communicating with the sensors and motor driver based on the movement of the sun.

[1] Antonio L. and Steven H. (2005) "Handbook of Photovoltaic Science and Engineering", Wiley.
[2] Asmarashid P., Ammar H. and Handy M. (2011) "A Design of Single Axis Sun Tracking System", The 5th International Power
Engineering and Optimization Conference, Malaysia, PP 107-110.
[3] Gagari D. and Arijit R. (2012) "Use of Solar Tracking System for Extracting Solar Energy", International Journal of Computer and
Electrical Engineering, Vol.4.
[4] Lee C., Chou P., Chiang C. and Lin C. (2009) "Sun Tracking Systems: A Review", Sensors.
[5] Mohammed S., Mizanuel S., Rafe S. and Taufik S. (2011) "Solar Tracking System" National Conference on Electronic Technologies.
[6] Nader B. and Pandian V. (2010) "Simplified Solar Tracking Prototype", Global Journal on Technology and Optimization, Vol.1.
[7] Norbert C., Shi-Wei Z., Wai-Chuen G., Zhen-Gang S. and San-Chin K. (2008) "A solar tracking system design based on linear
switched reluctance motor", Control Theory Applications, Vol.25.
[8] Plesz B., Sagi P. and Timar-Howath V. (2009) "Enhancement of Solar Panels" Power Generation by the Usage of Solar Tracking",
Proceedings of ECOpole, Vol.3.
[9] Rick J. and Chaiko Y. (2008) "Solar Tracking System: More Efficient Use of Solar Panels", World Academy of Science.
[10] Theraja B. L. and Theraja A. K. (2009): A Textbook of Electrical Technology, 23rd Edition, S. Chand and Company Ltd., New
Delhi

Abstract: This paper is an analysis of a rural distribution network to examine what are the benefits of centralized and decentralized generation. Decentralized or distributed power generation (DG) play an increasing role in the liberalized electricity market. Decentralized generation can have a significant impact on the power flow, voltage, profile, voltage stability and get better power quality for both the customers and electricity suppliers. We use load flow analysis to simulate the line condition of different feeders connected in rural area. In this paper, models of distribution system with considerable distributed power generation are discussed to improve the power quality and voltage stability and also present a framework for valuing ancillary service from the generator Vi2, reactive power this provide an improved plan and better utilities for the developing countries to get their system to meet dispersed load while optimizing for renewable and other decentralized source.

Keywords -Distributed power generation, Network Modeling, Load flow analysis, Voltage profile and distribution losses.

[1] H.L. Willis and W.G. Scott, "Distributed Power Generation" Planning and Evaluation", Marcel Dekker Inc. New York, 2000.
[2] P. Kundur, "Power System Stability and Control", McGraw-Hill, New York, 1993.
[3] T Van Cutsem "Volatge Instability : Phenomena, Counter measure and analysis method".
[4] Lomi Abraham, " Selection of Static VAR Compensator Location and Size for System Voltage Stability Improvement", International
Journal of Electric Power System Research, Elsevier, May 2000.
[5] C.A. Lanizares, A.C.Z.deSouza, and V.H.Quitana,"Comparison of Performance indices for Detection of Proximity to voltage
Collapse", IEEE Transaction of Power Systems, 11(3), August1996,pp. 1441-1450.
[6] K.Maki, S.Repo, P. Jarventausta "Impact of distribution generator as a part of distribution network planning" Tamper University of
technology, Institute of power Engineering.
[7] Umar Naseem Khan, Impact of distributed generator on electrical power network, Wroclaw university of technology, Wroclaw,
Poland 2008.
[8] Loi, Lei,Lai Tzefun chan, distributed Generation, Induction and Permanent Magnet Generator, John Wiley & Sons Ltd 2007.
[9] Baughman M.L.,Ss, S.N. Zarnikau, J.W advanced princing in electrical system part 1, theory IEEE.
[10] Hoff T Shugai, D.S. the value of grid supported photo voltaic to substation transformer in 13th IEEE T&D conference.B. L. and Theraja A. K. (2009): A Textbook of Electrical Technology, 23rd Edition, S. Chand and Company Ltd., New Delhi

Abstract: A reliable, affordable and secure supply of energy is important for socio-economic development. As a country of acute power crisis Bangladesh is now looking forward to develop its renewable energy sources in addition to its traditional sources of fossil fuel. It has very limited non renewable energy sources of its own but it's endowed with renewable energy sources like biomass, wind, hydro and solar insolation. The following research paper is based on the prospects of solar energy from perspective of Bangladesh. Possible implementations of solar technologies like photovoltaic cells (PV) and Solar thermal energy (STE) are discussed with their optimum capacity, efficiency, storage facility and cost per unit power. Some social, economic and environmental constraints regarding the implementation of solar technology are highlighted and some possible solutions are offered.

Keywords- DC micro grid, Irrigation, Solar energy, Solar Based Recharging Stations, Solar cooking

[1] Norman Mariun, Sayed Zahurul Islam "Global Scenario of Renewables and challenges to meet the future energy demand"
[2] An Assessment of Solar Energy Conversion Technologies and Research Opportunities, GCEP Energy Assessment Analysis Summer
2006
[3] SHAKIR-ul haque Khan, TOWFIQ-ur-Rahman, SHAHADAT Hossain.‟A brief study of the prospect of solar energy in generation
of electricity in Bangladesh‟ Cyber Journals: Multidisciplinary Journals in Science and Technology, Journal of Selected Areas in
Renewable and Sustainable Energy (JRSE), June Edition, 2012
[4] Last day of access (February19, 2013)[Online] Available http://www.wisegeek.com/what-is-solar-thermal-energy.htm
[5] H R Ghosh, S M Ullah, S K Khadem, N C Bhowmik and M Hussain "Measurement and Estimation of sunshine duration for
Bangladesh" Renewable Energy Research Center, University of Dhaka, Bangladesh
[6] Last day of access (February18, 2013)[Online] Available http://solartradingpost.com/solar -angle-calculators.html
[7] Muhammad Hager Mollah an Analysis, Design and Opportunity of Solar Based Recharging Stations for Electric Vehicles in
Bangladesh. Conference paper on "the developments in Renewable Energy Technology, (ICDRET '12)" January 2012 Dhaka
Bangladesh
[8] Last day of access (February18, 2013)[Online] Available http://www.altestore.com/store/Enclosures-Electrical-Safety/Electrical
Enclosures/Combiner-Pass-Through-Boxes/Midnite-Solar-MNPV3-Combiner-Box/p4567/
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Abstract: The paper introduces the modeling and control of z-source inverter, interfacing a Photovoltaic panel with a grid system. The main objective, of the work is to analyze the behavior of z-source inverter over a conventional inverter and boost converter arrangement. The approach is simulated as a MATLAB/SIMULINK model and results are used to study the characteristics of the proposed model. A sinusoidal waveform is produced at the inverter output, without any introduction of delay time between boost converter and inverter circuit.

Keywords: Z-source inverter (ZSI), Photovoltaic (PV) array, grid, shoot through, non shoot through, modulation index.

[1] Marcelo Gradella Villalva, Jonas Rafael Gazoli, and Ernesto Ruppert Filho ―Comprehensive Approach to Modeling and Simulation of Photovoltaic Arrays‖ IEEE Transactions on Power Electronics, vol. 24, no.5, may2009
[2] Yi Huang, Miaosen Shen, Yi Huang, Miaosen Shen, and Jin Wang ―Z-Source Inverter for Residential Photovoltaic Systems‖ IEEE Transactions on Power Electronics, vol. 21, no. 6, november 2006.
[3] Poh Chiang Loh, D. Mahinda Vilathgamuwa, Chandana Jayampathi Gajanayake, Yih Rong Lim, and Chern Wern Teo ―Transient Modeling and Analysis of Pulse-Width Modulated Z-Source Inverter‖ IEEE Transactions on Power Electronics, vol. 22, no. 2, march 2007.
[4] Xiaogao Chen, Qing Fu, Shijie Yu, Longhua Zhou ―Unified Control of Photovoltaic Grid-Connection and Power Quality managements‖ 2008 Workshop on Power Electronics.
[5] Miaosen Shen, Qingsong Tang, Fang Z. Peng ―Modeling and Controller Design of the Z-Source Inverter with Inductive Load‖ 2007 IEEE
[6] Baoming Ge, Qin Le, Fang Zheng Peng, Dongsen Song, Yushan Liu and Abu Rub Haitham ―An Effective PV Power Generation Control System using Quasi-Z Source Inverter with Battery‖ 2011 IEEE.
[7] Fabricio Bradaschia, Marcelo C. Cavalcanti, Pedro E. P. Ferraz, Francisco A. S. Neves, Euzeli C. dos Santos, Jr., Joao H. G. M. a Silva ―Modulation for Three-Phase Transformerless Z- Source Inverter to Reduce Leakage Currents in Photovoltaic Systems‖ IEEE Transactions on Industrial Electronics, vol. 58, no. 12, december 2011
[8] Jingbo Liu, Jiangang Hu, and Longya Xu ―Dynamic Modeling and Analysis of Z Source Converter—Derivation of AC Small Signal Model and Design-Oriented Analysis‖ IEEE Transactions on Power Electronics, vol. 22, NO. 5, september 2007
[9] Po XU, Xing ZHANG, Chong-wei ZHANG, Ren-xian,CAO and Liuchen CHANG ―Study of Z-Source Inverter for Grid- Connected PV Systems‖ IEEE Conference Publications Year 2006.
[10] C. J. Gajanayake, D. Mahinda Vilathgamuwa, Poh Chiang Loh ―Modeling and design of multi-loop closed loop controller for Z-source inverter for Distributed Generation‖ School of Electrical and Electronic Engineering 2006.

Abstract: Power System Fault Analysis of The Nigerian 330kV Transmission Grid is a study of the determination of the appropriate circuit breaker. Relevant data were sourced from NCC, Osogbo and a digital computer fault analysis program was applied. The circuit breakers considered are SF6, Air, Oil and Vacuum and the designed criteria employed in the use of multi-criteria analysis are Cost, reliability, Flexibility and Environmental Impact. The Multi-Criteria Analysis (MCA) approach is an improvement over the traditional approach for calculating the symmetrical fault current at a system location and then selects a circuit breaker with a symmetrical interrupting capability equal to or above the calculated current. In the MCA approach, user preferences which take into account the design criteria were not ignored, as a result, a logical and rational approach has been developed for the Nigerian 330kV power system network which meets the input specifications and responds to user preference and concerns of power system operators.

Keywords: Power System, Circuit Breakers, Multi-criteria Analysis, Short-Circuit MVA, Three-phase Fault, Weighted Sum Average

[1] Muhammad, Aree A. (2011), ""Simulation of Different Types of Faults on Northern Iraq Power System‟‟, IGEC VI – 2011 – 028 [2] Ibe, A.O. and Uzonwa, N.K. (2005), ""Power System Simulation for Short Circuit Current in the Selection of Switchgears‟‟, Nigerian Journal of Industrial and Systems Studies, Vol. 4, No. 3, pp 9 – 15.

[3] El-Hawary, M.E. (2008), ""Introduction to Electrical Power System‟‟, Wiley, IEEE Press.

[4] Jona, J. and Atkinson-Hope, G. (2009), ""Multi-Criteria Analysis for the Sizing and Selection of Circuit Breakers in Power Systems‟‟, International Journal of Innovation in Energy Systems and Power. Vol. 4, No. 1, pp 9 – 13.

[5] Hewitson Les, Brown Mark and Ramesh Ben, (2004), ""Practical Power System Protection‟‟, IDC Technologies.

[6] Okelola, M.O., Yussuf, A.A., and Awosope, C.O.A. (2005), ""Fault Analysis: An Application of Venin‟s Method to 330kV Transmission Grid System in Nigeria‟‟, LAUTECH Journal of Engineering and Technology, Vol. 3, No. 1, pp 30 – 43.

[7] Tijani M.A. and Olatunji D.O. (2011), ""An Evaluation of Three-Phase Fault Currents on the Nigerian 330kV Transmission Grid‟‟. Journal of Research in Technology and Engineering Management, Vol. 4, No. 2, pp. 37 – 45.

[8] Okemiri, O.N., (2008), ""Basic Protection Scheme on Power System‟‟, The Nigerian Tribune, Tuesday 12th February 2008, pp 24. [9] Glover J.D., and Sarma M., (1989), ""Power System Analysis and Design‟‟, PWS-KENT, Wadworth, Inc.

[10] http/www.dtlr.gov.uk/multicriteria/index.htm

Abstract: This paper presents a single phase AC/DC/AC converter based on parallel AC/DC and cascaded multi-level DC/AC Converter. For a two-cell AC/DC/AC converter, two units of full-bridges are connected in parallel and two units of full-bridges are connected in cascade. It is proposed that instead of using two separate control loops of DC link voltages at the AC to DC conversion stage, only a single control loop with only one voltage sensor is proposed in this paper when two cells are equally loaded. It is also shown that by controlling only one cell DC link voltage, the other dc link voltage also gets controlled automatically. Use of simple and unipolar ramp comparison control at both the stages leads to fixed switching frequency operation of all the switches along with the improved quality of input current and output voltage as compared to simple PWM control. The simulation result for the proposed topology has been obtained through the MATLAB simulation studies, for a two-cell based parallel cum cascaded AC/DC/AC converter. The experimental verification of the proposed topology and control strategy has been obtained.

Index Terms: AC/DC converter, DC/AC converter, AC/DC/AC Converter, Parallel Converter, Unipolar PWM.

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