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Ahmadābād, India

Singh A.K.,Institute of Infrastructure | Parida S.K.,Indian Institute of Technology Patna
Sustainable Energy Technologies and Assessments | Year: 2015

The integration of renewable energy sources (RESs) based DGs into grid has a great importance in improving system reliability. Many methods were proposed in the literature for finding best locations for DG placement considering various criteria. Sometime, it becomes difficult for combined placement of different kinds of renewable based DGs, such as solar, wind and fuel cell. The criterion of minimizing total system cost was used previously by many researchers for locating the optimal sites for DGs using OPF formulations. In this case, three different cost functions are formulated for different kinds of renewable energy sources (RESs). By taking combined cost function of all the RESs in the OPF to identify location for each different kind of sources becomes very cumbersome task. It would be difficult to find the exact locations for various kinds of RESs that is where to place which type of RESs. In order to solve this difficulty, three different objectives have been considered separately for determining the optimal locations for each kind of RESs using mixed integer nonlinear programming (MINLP) method considering loadability, losses and cost. Having many alternatives with these three objectives, analytic hierarchy process (AHP) has been used to make a decision over getting the optimal locations for these different kinds of RESs. The proposed methodology has been demonstrated on 15-node radial distribution system and 69-node mesh distribution system. © 2015 Elsevier Ltd. Source


Singh A.K.,Institute of Infrastructure | Parida S.K.,Indian Institute of Technology Patna
International Journal of Electrical Power and Energy Systems | Year: 2015

Many methods were proposed in the literature for finding best allocations for DG placement considering various objectives. Sometimes, it becomes cumbersome task for system planners to select the objective for DG allocation based on utility and customer point of view. For this purpose, a set of optimization functions and sensitivity factors have been developed for allocation of DGs in the system. The optimization method consists of maximizing loadability, minimizing losses and cost while satisfying power system constraints. The sensitivity factor comprises voltage performance index and loss sensitivity factor for DG allocation. A decision made by system planner (DMSP) approach has been proposed to decide the allocation of DGs in the system based on utilities and customer demand. For this purpose, first DG locations have been planned in the system based on various objectives. Then, suitable objective has been decided from utility and customer necessities by DMSP. Having these in order, DMSP and analytic hierarchy process (AHP) has been used to make a decision over getting the appropriate locations for DGs placement in the system. A combined suitable option for DG allocations with equal weightage to the various objectives has also been studied in this work. © 2014 Elsevier Ltd. All rights reserved. Source


This research addresses system reliability analysis using weakest t-norm based approximate intuitionistic fuzzy arithmetic operations, where failure probabilities of all components are represented by different types of intuitionistic fuzzy numbers. Due to the incomplete, imprecise, vague and conflicting information about the component of system, the present study evaluates the reliability of system in terms of membership function and non-membership function by using weakest t-norm (Tw) based approximate intuitionistic fuzzy arithmetic operations on different types of intuitionistic fuzzy numbers. In general, interval arithmetic (α-cut arithmetic) operations have been used to analyze the fuzzy system reliability. In complicated systems, interval arithmetic operations may occur the accumulating phenomenon of fuzziness. In order to overcome the accumulating phenomenon of fuzziness, this research adopts approximate intuitionistic fuzzy arithmetic operations under the weakest t-norm arithmetic operations (T w) to analyze fuzzy system reliability. The approximate intuitionistic fuzzy arithmetic operations employ principle of interval arithmetic under the weakest t-norm arithmetic operations. The proposed novel fuzzy arithmetic operations may obtain fitter decision values, which have smaller fuzziness accumulating and successfully analyze the system reliability. Also weakest t-norm arithmetic operations provide more exact fuzzy results and effectively reduce fuzzy spreads (fuzzy intervals). Using proposed approach, fuzzy reliability of series system and parallel system are also constructed. For numerical verification of proposed approach, a malfunction of printed circuit board assembly (PCBA) is presented as a numerical example. The result of the proposed method is compared with the listing approaches of reliability analysis methods. © 2014 Elsevier B.V. Source


Singh A.K.,Institute of Infrastructure | Parida S.K.,Indian Institute of Technology Patna
International Journal of Electrical Power and Energy Systems | Year: 2016

This paper presents a method to select the load buses for the placement of Distributed generation (DG) based on loss reduction and voltage improvement sensitivity of the system. The strategic placement of DGs can help in reducing power losses and improving voltage profile. The proposed work discusses some new sensitivity factors that can be useful for selecting the locations. The method has the potential to be used for integrating the available DGs by identifying the best locations in a power system. The proposed method has been demonstrated on IEEE 24-bus Reliability Test System (RTS). © 2015 Elsevier Ltd. All rights reserved. Source


Patel K.N.,M. S. University of Baroda | Prajapati A.K.,M. S. University of Baroda | Kamath B.V.,Institute of Infrastructure | Bedekar A.V.,M. S. University of Baroda
Liquid Crystals | Year: 2016

A series of (2E,6E)-2-(4-n-alkoxybenzylidene)-6-((benzo[d][1,3]dioxol-6-yl)methylene)cyclohexanones were synthesised by stepwise condensation reactions from cyclohexanone. The optical and thermal analysis of the series indicated the mesomorphic properties of some derivatives. The compounds with C7–C16 substituents showed the nematic phases in the range of 90–73°C. The single crystal X-ray analysis confirms the head to tail packing arrangement. © 2016 Taylor & Francis Source

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