Performance Analysis of Maximum Power Point Tracking Algorithms Under Varying Irradiation

Photovoltaic (PV) system is one of the reliable alternative sources of energy and its contribution in energy sector is growing rapidly. The performance of PV system depends upon the solar insolation, which will be varying throughout the day, season and year. The biggest challenge is to obtain the maximum power from PV array at varying insolation levels. The maximum power point tracking (MPPT) controller, in association with tracking algorithm will act as a principal element in driving the PV system at maximum power point (MPP). In this paper, the simulation model has been developed and the results were compared for perturb and observe, incremental conductance, extremum seeking control and fuzzy logic controller based MPPT algorithms at different irradiation levels on a 10 KW PV array. The results obtained were analysed in terms of convergence rate and their efficiency to track the MPP.Keywords: Photovoltaic system, MPPT algorithms, perturb and observe, incremental conductance, scalar gradient extremum seeking control, fuzzy logic controller.Article History: Received 3rd Oct 2016; Received in revised form 6th January 2017; Accepted 10th February 2017; Available onlineHow to Cite This Article: Naick, B. K., Chatterjee, T. K. & Chatterjee, K. (2017) Performance Analysis of Maximum Power Point Tracking Algorithms Under Varying Irradiation. Int Journal of Renewable Energy Development, 6(1), 65-74.http://dx.doi.org/10.14710/ijred.6.1.65-7

Gravimetric Estimation of Mn(II) with Sodium Benzilate

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Complexes of Co(II), Ni(II), Cu(II), Mn(II) & U(VI) with Benzilic, ɑ-Phenyllactic & Mandelic Acids

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Vibrio cholerae hemolysin: The β-trefoil domain is required for folding to the native conformation

AbstractVibrio cholerae cytolysin/hemolysin (VCC) is a 65kDa β-pore-forming toxin causing lysis and death of eukaryotic cells. Apart from the core cytolysin domain, VCC has two lectin domains with β-trefoil and β-prism folds. The β-prism domain binds to cell surface carbohydrate receptors; the role of the β-trefoil domain is unknown. Here, we show that the pro-VCC mutant without the β-trefoil domain formed aggregates highly susceptible to proteolysis, suggesting lack of a properly folded compact structure. The VCC variants with Trp532Ala or Trp534Ala mutation in the β-trefoil domain formed hemolytically inactive, protease-resistant, ring-shaped SDS-labile oligomers with diameters of ~19nm. The Trp mutation induced a dramatic change in the global conformation of VCC, as indicated by: (a) the change in surface polarity from hydrophobic to hydrophilic; (b) movement of core Trp residues to the protein-water interface; and (c) decrease in reactivity to the anti-VCC antibody by >100-fold. In fact, the mutant VCC had little similarity to the wild toxin. However, the association constant for the carbohydrate-dependent interaction mediated by the β-prism domain decreased marginally from ~3×108 to ~5×107M−1. We interpret the observations by proposing: (a) the β-trefoil domain is critical to the folding of the cytolysin domain to its active conformation; (b) the β-prism domain is an autonomous folding unit

Kinetics of Os(VIII)-catalysed Oxidation of Neutralized Glyoxylic & Pyruvic Acids by Alkaline Hexacyanoferrate(III)

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Kinetics of Oxidation of Neutralized Glyoxylic & Pyruvic Acids by Alkaline Hexacyanoferrate(III)

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Optimal Controller Design for Thermal Power System with Feedback Linearization

The main objective of this paper is to device a method for construction of state-feedback control law for a single area thermal power system .In this method, first plant model is transformed into the controller form and constructs a state feedback controller in the new coordinates and then using the inverse transformation; represent the controller in the original coordinates. While constructing the controller in the new coordinates, a part of the controller is used to cancel nonlinearities, thus resulting in a linear system in the new coordinates. Simulation results in a single reheat thermal system are provided to illustrate the effectiveness of the proposed nonlinear control scheme.DOI:http://dx.doi.org/10.11591/ijece.v2i5.55

FACTS BASED CONTROLLER FOR INTERCONNECTED HYDROTHERMAL POWER SYSTEM

Abstract: This research paper introduce the FACTS based decentralized controller for load frequency control of two area interconnected hydrothermal power system considering the combined effect of RFB ( Redox Flow Batteries ) and TCPS ( Thyristor Control Phase Shifter ) as a FACTS device which is incorporated with tie-line power flow of the given system. The proposed controller is design using genetic algorithm based integral controller in which Integral Square Error (ISE) criterion is consider for the optimization of the system error. This proposed controller is implemented into the two area interconnected hydrothermal power system and its different performance is studies with and without RFB and TCPS control scheme. This studies revels that the proposed controller gives better transient responses and helps in better stabilizing frequency response as well as improve the tie line power flow of the system

Differentiated Services In Wireless Data Networks

With the introduction of wireless data services, attention has to be paid in providing differentiated services to mobile hosts/users in a cellular radio system. Differentiated services (not to be confused with DiffServ) can be provided by managing the aggregated traffic flow from each service class in such a way that the revenue generated is maximized. We first provide an architectural framework in which the wireless system in conjunction with the service level agreement (SLA) database decides on the resource allocation to individual users. Cobb-Douglas utility function is used as the basis for the revenue from the carrier\u27s perspective. Then we represent each service class by a sub-space of the QoS space which is like a higher dimensional Euclidean space. We apply vector quantization to shrink the infinite-point space to a finite-point space by partitioning the former into N regions such that the points (identified by a QoS index) within a region reflect almost similar system performance. Once the QoS space is characterized, we show how different sub-spaces can be mapped to the various service classes. We also demonstrate how apriori knowledge of the operating point region helps in any decision pertaining to call admission and resource allocation which eventually maximizes the utility function