iosr-JEEE   Volume-10 ~ Issue-4 ~ July-August 2015

Abstract: Now a day's dc-dc switching converters are widely used for sophisticated application. By using these converters with given dc input voltage a stabilised output voltage can be obtained by using Buck (lower), Boost (higher) or Buck –Boost (generic) topology which improves the efficiency of dc-dc converter as compared to linear regulators. Most used technique to control switching power supply is pulse width modulation (PWM). In this way a particular dc-dc converter is designed by keeping the typical application in mind. A properly designed dc-dc converter provide low ripple, better noise rejection, reliable and efficient converter. For some typical application like powering LED needs constant current supply for constant illumination, hence feedback based closed loop converters becomes better choice.

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[5]. R.D. Middlebrook and S. Cuk, "A General Unified Approach To Modelling Switching Converter Power Stages", IEEE Power Electronics Specialists Conference, 1976 Record, pp 18-34.

Abstract: Nigeria is rich in terms of energy resources, both renewables and non-renewables, which can provide the country's demand and long awaited ambition for sufficient and reliable electricity to all Nigerians. But unfortunately Nigeria's rate of electricity consumption per capita is among the lowest in Africa. This is associated with ineffective implementation of the energy policy in Nigeria. The objective of this paper is to presents a review of conventional and renewable energy to be used for constant and reliable electricity supply in the country. Conventional and renewable energy resources are discussed, also the current government policies are not left out.

[1]. U. B. Akuru, ―Renewable Energy Investment in Nigeria : A Review of the Renewable Energy Master Plan,‖ pp. 166–171, 2010.
[2]. S. O. Oyedepo, ―Energy and sustainable development in Nigeria: the way forward,‖ Energy. Sustain. Soc., vol. 2, no. 1, p. 15, 2012.
[3]. T. Sesan, ―Status of Renewable Energy Policy and Implementation in Nigeria,‖ no. April, 2008.
[4]. Y. S. Mohammed, M. W. Mustafa, N. Bashir, and a. S. Mokhtar, ―Renewable energy resources for distributed power generation in Nigeria: A review of the potential,‖ Renew. Sustain. Energy Rev., vol. 22, pp. 257–268, Jun. 2013.
[5]. C. Area, ―Renewable energy development in nigeria*,‖ pp. 21–24, 2010.
[6]. ―A Critical Review of the Nigerian Energy Scenario,‖ vol. 5, no. 3, pp. 55–67, 2013.

Abstract: This paper proposed novel multilevel inverter with low number of switches. Multilevel inverters are applicable for high power purpose in industries which become very popular. When compared to two level inverters these multilevel inverters produces good quality of output wave from. In such a way that, at first new proposed topology which as sub multilevel inverter is designed after that cascaded connection of sub multi level inverters called as novel cascaded multilevel inverter is proposed. This proposed novel cascaded multilevel inverter uses less number of switching devices.

[1]. J. Rodriguez, J. S. Lai, and F. Z. Peng, "Multilevel inverters: A survey of topologies, controls, and applications," IEEE Trans. Ind. Electron.,vol. 49, no. 4, pp. 724–738, Aug. 2002.
[2]. J. H. Kim, S. K. Sul, and P. N. Enjeti, "A carrier-based PWM method with optimal switching sequence for a multilevel four-leg voltage-source inverter," IEEE Trans. Ind. Appl., vol. 44, no. 4, pp. 1239–1248, Jul./Aug.2008.
[3]. O. Lopez, J. Alvarez, J. Doval-Gandoy, F. D. Freijedo, A. Nogueiras, A. Lago, and C. M. Penalver, "Comparison of the FPGA implementation of two multilevel space vector PWM algorithms," IEEE Trans. Ind. Electron., vol. 55, no. 4, pp. 1537–1547, Apr. 2008.
[4]. Boora, A. Nami, F. Zare, A. Ghosh, and F. Blaabjerg, "Voltagesharing converter to supply single-phase asymmetrical four-level diode clamped inverter with high power factor loads," IEEE Trans. Power Electron., vol. 25, no. 10, pp. 2507–2520, Oct. 2010.
[5]. J. Rodriguez, S. Bernet, P. Steimer, and I. Lizama, "A survey on neutral point clamped inverters," IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 2219–2230, Jul. 2010.

Abstract: Switched reluctance motor (SRM) drives are simpler in construction compared to induction andsynchronous motors. Their combination with power electronic controllers may yield an economicalsolution [1]. The structure of the motor is simple with concentrated coils on the stator and neitherwindings nor brushes on the rotor. This apparent simplicity of its construction is deceptive. SRMdrives present several advantages as high efficiency, maximum operating speed, good performanceof the motor in terms of torque/inertia ratio together with four-quadrant operation, making it anattractive solution for variable speed applications. The very wide size, power and speed rangetogether with the economic aspects of its construction, will give the SRM place in the drives family.

[1]. R. Krishnan, Switched reluctance motors drives. CRC Press, 2001
[2]. J.M. Kokernak, D.A Torrey, ―Magnetic circuit model for the mutually coupled switched-reluctance machine,‖ IEEE Trans on Magnetics, vol. 36, no.2, pp.500-507, 2000.
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[4]. John R. Suriano. Design methodology for low speed variable reluctance motors. Purdue University, School of ElectricalEngineering, 1992. – 90 p.
[5]. Krishnan Ramu. Switched reluctance motor drives: modeling, simulation, analysis, design, andapplications. – Boca RatonLondon New York Washington, D.C., 2001. – 416 p.

Abstract: Wireless sensor networks are network of compact micro sensors with wireless communication capability. These sensors have been made viable by convergence of micro-electro-mechanical system (MEMS) technologies and digital electronics. As autonomous devices, they can provide pervasive distributed and collaborative network of computer nodes. There is a wide variety of applications of wireless sensor networks at domestic and industrial level. The factors influencing the design of the sensor networks such as energy resources and power consumption are needed to be taken under consideration.

[1] D. Nadiag, S.S. Iyengar, A New Architecture for distributed sensor integration, Proceedings of IEEE Southeastcon'93.
[2] Paul Lettierei and Mani B. Srivastav, Advances in wireless Terminals, IEEE Personal Communications, February, 1999.
[3] C. Lynch and F.O. Reilly. Pic Based Tiny OS implementation. In proc. 2nd European Workshop on Wireless Sensor Networks, EWSN 2005, Istanbul, pages 378-385, Feb. 2005.

Abstract: The induction motors arecharacterized by complex,non-linear and time-varying dynamics, and hence their speed control is always a challenging problem. There are lot of speed control techniques are available. Out of all that techniques sliding mode control is an efficient one for the speed control due to its robustness and insensitivity to the parameter variation. In this paper, a sliding mode controller is designed for the speed control of Two Phase Induction Motor (TPIM) and TPIM is the viable replacement for the Single Phase Induction Motor (SPIM)

IndexTerms: Sliding mode control, single phase induction motor, two phase induction motor, chattering phenomenon

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Abstract: A Mobile Ad-Hoc Network (MANET) is a collection of wireless mobile nodes that is self-organized to form an arbitrary topology with the absence of fixed infrastructure or centralized administration .In such environment security has become a main concern to provide confidentiality, authentication, integrity, availability, access control, and non-repudiation.

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[6]. H. Bettahar, A. Bouabdallah, and Y. Challal, "An adaptive key management protocol for secure multicast," in 11th International Conference on Computer Communications and Networks ICCCN, Florida USA, Oct. 2002.

Abstract: Solar Energy is the clean and renewable source of energy. Solar PV systems are gaining attraction for energy generation in these days of increasing energy demand due to its reducing cost and new researches carried on its efficient use. The solar cell is always operated at its Maximum Power Point for better results. There are different methods to search the maximum power point of PV system. In this paper, a Maximum Power Point Tracking method for Solar PV system using Sliding Mode Control is proposed. The PV system modeling practice under standard test conditions is discussed.

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