iosr-JEEE   Volume-3 ~ Issue-4

Abstract: The various optimal capacitor placement techniques on transmission and distributions lines for line losses reduction and enhancement of voltage stability in the power system network have been proposed so far in different papers. Optimal Capacitor placement is an optimization problem which has an objective to define the sizes and locations of capacitors to be installed. This paper focuses on the optimal capacitor placement and sizing problem formulation and analytical as well as heuristic artificial intelligence optimization methods for optimal capacitor placement and sizing. This paper helps the researchers to know about the different methods presented so far for optimal capacitor placement and sizing in transmission and distribution networks so that further work on optimal capacitor placement can be carried out for better results.
Keywords -capacitor sizing, distribution system, heuristic techniques, optimal capacitor placement, reactive power, transmission system, voltage stability.

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Abstract:This paper presents an approach to Embedded Based Flyback Converter with Programmable Switching Frequency for Efficiency Optimization. The fly-back converters are popularly used in digital systems for achieving voltage regulation of dc supply. Normally the switching losses and cost is high in existing system. So here we proposed to develop an embedded based fly-back converter with programmable switching frequency in order to optimize the efficiency. The valley switching technique is used by sensing the valley point of switch voltage with Zero Voltage switching technique. The zero voltage switching technique is used hereto reduce the switching losses.
Keywords: flyback converter, valley switching, efficiency optimization,ZVS

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Abstract:The development of All Electric Aircraft has provided new opportunities in the area of electronic devices and power electronics. The purpose of this paper is to compare the properties of soft-switching converter topologies when used to achieve dc-dc conversion at high-power and high-voltage levels. The circuit investigated in this paper can operate in a soft-switching manner enabling reduction in device switching losses and therewith an increase in switching frequency. the ZVS soft-switching region of a DAB converter with arbitrary operating waveforms. The effect of the junction capacitor of the device and the magnetizing inductance of the transformer are also analyzed. Through the analysis, a group of waveforms for different loading conditions are identified to maximize the ZVS operating region. The results are verified by simulation using real device models.
Keywords:DAB converter, soft switching, flyback converter, ultra capacitor bank.

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Annu. Meet., Oct. 2008, pp. 1–7. NAAYAGI et al.: HIGH-POWER BIDIRECTIONAL DC–DC CONVERTER FOR AEROSPACE APPLICATIONS 4379