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Power loss reduction of distribution systems using BFO based optimal reconfiguration along with DG and shunt capacitor placement simultaneously in fuzzy framework

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Journal of Central South University 2017年第1期24卷 90-103页

作者： m.mohammadi A.mohammadi Rozbahani S.Bahmanyar Department of Electrical Engineering Borujerd BranchIslamic Azad UniversityBorujerdIran

In distribution systems,network reconfiguration and capacitor placement are commonly used to diminish power losses and keep voltage profiles within acceptable ***,the problem of DG allocation and sizing is great *** this work,a combination of a fuzzy multi-objective approach and bacterial foraging optimization(BFO) as a meta-heuristic algorithm is used to solve the simultaneous reconfiguration and optimal sizing of DGs and shunt capacitors in a distribution *** objective is transferred into fuzzy domain using its membership ***,the overall fuzzy satisfaction function is formed and considered a fitness function inasmuch as the value of this function has to be maximized to gain the optimal *** numerical results show that the presented algorithm improves the performance much more than other meta-heuristic *** results found that simultaneous reconfiguration with DG and shunt capacitors allocation(case 5) has 77.41%,42.15%,and 56.14%improvements in power loss reduction,load balancing,and voltage profile indices,respectively in 33-bus test *** result found 87.27%,35.82%,and 54.34%improvements of mentioned indices respectively for 69-bus system.

关键词： network reconfiguration distributed generation (DG) capacitor banks fuzzy framework bacterial foragingoptimization

Kinetics of(TBAF+CO2)semi-clathrate hydrate formation in the presence and absence of SDS

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Petroleum Science 2018年第2期15卷 375-384页

作者： A.mohammadi m.Pakzad A.H.mohammadi A.Jahangiri Department of Chemical Engineering University of BojnordBojnordIran Department of Chemical Engineering Omidiyeh BranchIslamic Azad UniversityOmidiyehIran Institut de Recherche en Genie Chimique et Petrolier(IRGCP) Paris CedexFrance Thermodynamics Research Unit School of EngineeringUniversity of KwaZulu-NatalHoward College CampusKing George V AvenueDurban 4041South Africa Faculty of Engineering Shahrekord UniversityShahrekordIran

In this communication, the impacts of adding SDS （sodium dodecyl sulfate）, TBAF （tetra-n-butylammonlum tluorloe） ano the mixture of SDS ＋ TBAF on the main kinetic parameters of CO2 hydrate formation （induction time, the quantity and rate of gas uptake, and storage capacity） were investigated. The tests were performed under stirring conditions at T = 5 ℃ and P = 3.8 mPa in a 169 cm3 batch reactor. The results show that adding SDS with a concentration of 400 ppm, TBAF with a concentration of l-5 wt%, and the mixture of SDS ＋ TBAF, would increase the storage capacity of CO2 hydrate and the quantity of gas uptake, and decrease the induction time of hydrate formation process. The addition of 5 wt% of TBAF and 400 ppm of SDS would increase the CO2 hydrate storage capacity by 86.1% and 81.6%, respectively, compared to pure water. Investigation of the impact of SDS, TBAF and their mixture on the rate of gas uptake indicates that the mixture of SDS ＋ TBAF does not have a significant effect on the rate of gas uptake during hydrate formation process.

关键词： Semi-clathrate hydrate Gas hydrate Kinetics CO2 SDS TBAF

Bacterial graphical user interface oriented by particle swarm optimization strategy for optimization of multiple type DFACTS for power quality enhancement in distribution system

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Journal of Central South University 2017年第3期24卷 569-588页

作者： m.mohammadi m.montazeri S.Abasi Department of Electrical Engineering Borujerd Branch Islamic Azad University Borujerd Iran

This study proposes a graphical user interface(GUI) based on an enhanced bacterial foraging optimization(EBFO) to find the optimal locations and sizing parameters of multi-type DFACTS in large-scale distribution *** proposed GUI based toolbox,allows the user to choose between single and multiple DFACTS allocations,followed by the type and number of them to be *** EBFO is then applied to obtain optimal locations and ratings of the single and multiple *** is found to be faster and provides more accurate results compared to the usual PSO and *** obtained with mATLAB/Simulink simulations are compared with PSO,BFO and enhanced *** reveals that enhanced BFO shows quick convergence to reach the desired solution there by yielding superior solution *** results concluded that the EBFO based multiple DFACTS allocation using DSSSC,APC and DSTATCOm is preferable to reduce power losses,improve load balancing and enhance voltage deviation index to 70%,38% and 132% respectively and also it can improve loading factor without additional power loss.

关键词： distribution system power quality single type and multiple type DFACTS BFO algorithm particle swarm optimization(PSO)

Evaluation of a mathematical model using experimental data and artificial neural network for prediction of gas separation

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Journal of Natural Gas Chemistry 2008年第2期17卷 135-141页

作者： m.Peer m.mahdyarfar T.mohammadi Research Center for membrane Processes Department of Chemical EngineeringIran University of Science and TechnologyNarmakTehranlran Gas Division Research Institute of Petroleum IndustryTehranIran

In recent times, membranes have found wide applications in gas separation processes. As most of the industrial membrane separation units use hollow fiber modules, having a proper model for simulating this type of membrane module is very useful in achieving guidelines for design and characterization of membrane separation units. In this study, a model based on Coker, Freeman, and Fleming＇s study was used for estimating the required membrane area. This model could simulate a multicomponent gas mixture separation by solving the governing differential mass balance equations with numerical methods. Results of the model were validated using some binary and multicomponent experimental data from the literature. Also, the artificial neural network （ANN） technique was applied to predict membrane gas separation behavior and the results of the ANN simulation were compared with the simulation results of the model and the experimental data. Good consistency between these results shows that ANN method can be successfully used for prediction of the separation behavior after suitable training of the network

关键词： hollow fiber membrane gas separation mathematical modeling artificial neural network

Interacting Entropy-Corrected Holographic Scalar Field models in Non-Flat Universe

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Communications in Theoretical Physics 2011年第5期55卷 942-948页

作者： A.Khodam-mohammadi m.malekjani Physics Department Faculty of ScienceBu-Ali Sina University

In this work we establish a correspondence between the tachyon, k-essence and dilaton scalar field models with the interacting entropy-corrected holographic dark （ECHD） model in non-fiat FRW universe. The reconstruction of potentials and dynamics of these scalar fields according to the evolutionary behavior of the interacting ECHDE model are done. It has been shown that the phantom divide can not be crossed in ECHDE tachyon model while it is achieved for ECHDE k-essence and ECHDE dilaton scenarios. At last we calculate the limiting case of interacting ECHDE model, without entropy-correction.

关键词： holographic dark energy Tachyon model k-essence model dilaton model

Particle swarm optimization algorithm for simultaneous optimal placement and sizing of shunt active power conditioner(APC)and shunt capacitor in harmonic distorted distribution system

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Journal of Central South University 2017年第9期24卷 2035-2048页

作者： mohammadi mohammad Department of Electrical Engineering Borujerd BranchIslamic Azad UniversityBorujerdIran

Due to development of distribution systems and increase in electricity demand,the use of capacitor banks *** the other point of view,nonlinear loads generate and inject considerable harmonic currents into power *** this condition if capacitor banks are not properly selected and placed in the power system,they could amplify and propagate these harmonics and deteriorate power quality to unacceptable *** attention of disadvantages of passive filters,such as occurring resonance,nowadays the usage of this type of harmonic compensator is *** the other side,one of parallel multi-function compensating devices which are recently used in distribution system to mitigate voltage sag and harmonic distortion,performs power factor correction,and improves the overall power quality as active power conditioner(APC).Therefore,the utilization of APC in harmonic distorted system can affect and change the optimal location and size of shunt capacitor bank under harmonic distortion *** paper presents an optimization algorithm for improvement of power quality using simultaneous optimal placement and sizing of APC and shunt capacitor banks in radial distribution networks in the presence of voltage and current *** algorithm is based on particle swarm optimization(PSO).The objective function includes the cost of power losses,energy losses and those of the capacitor banks and APCs.

关键词： shunt capacitor banks active power conditioner multi-objective function particle swarm optimization (PSO) harmonic distorted distribution system

STABILITY OF A PREDATOR-PREY SYSTEm WITH PREY TAXIS IN A GENERAL CLASS OF FUNCTIONAL RESPONSES

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Acta mathematica Scientia 2016年第1期36卷 62-72页

作者： m.YOUSEFNEZHAD S.A.mohammadi Department of mathematical Sciences Sharif University of Technology Tehran Iran Department of mathematics College of Sciences Yasouj University Yasouj 75918-71934 Iran

In this paper, a diffusive predator-prey system with general functional responses and prey-tactic sensitivities is studied. Providing such generality, we construct a Lyapunov function and we show that the positive constant steady state is locally and globally asymptotically stable. With an eye on the biological interpretations, a numerical simulation is performed to illustrate the feasibility of the analytical findings.

关键词： predator-prey global stability steady state Lyapunov function

Exponential B-spline collocation method for numerical solution of the generalized regularized long wave equation

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Chinese Physics B 2015年第5期24卷 177-190页

作者： Reza mohammadi Department of mathematics University of Neyshabur

The aim of the present paper is to present a numerical algorithm for the time-dependent generalized regularized long wave equation with boundary conditions. We semi-discretize the continuous problem by means of the Crank-Nicolson finite difference method in the temporal direction and exponential B-spline collocation method in the spatial direction. The method is shown to be unconditionally stable. It is shown that the method is convergent with an order of θ（k2 ＋ h2）. Our scheme leads to a tri-diagonal nonlinear system. This new method has lower computational cost in comparison to the Sinc-collocation method. Finally, numerical examples demonstrate the stability and accuracy of this method.

关键词： solitary waves GRLW equation exponential B-spline collocation

Fuzzy-GA based algorithm for optimal placement and sizing of distribution static compensator (DSTATCOm) for loss reduction of distribution network considering reconfiguration

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Journal of Central South University 2017年第2期24卷 245-258页

作者： mohammad mohammadi mahyar Abasi A.mohammadi Rozbahani Department of Electrical Engineering Borujerd Branch Islamic Azad University

This work presents a fuzzy based methodology for distribution system feeder reconfiguration considering DSTATCOm with an objective of minimizing real power loss and operating cost. Installation costs of DSTATCOm devices and the cost of system operation, namely, energy loss cost due to both reconfiguration and DSTATCOm placement, are combined to form the objective function to be minimized. The distribution system tie switches, DSTATCOm location and size have been optimally determined to obtain an appropriate operational condition. In the proposed approach, the fuzzy membership function of loss sensitivity is used for the selection of weak nodes in the power system for the placement of DSTATCOm and the optimal parameter settings of the DFACTS device along with optimal selection of tie switches in reconfiguration process are governed by genetic algorithm(GA). Simulation results on IEEE 33-bus and IEEE 69-bus test systems concluded that the combinatorial method using DSTATCOm and reconfiguration is preferable to reduce power losses to 34.44% for 33-bus system and to 45.43% for 69-bus system.

关键词： distribution FACTS (DFACTS) distribution static compensator (DSTATCOm) network reconfiguration genetic algorithm fuzzy membership function power loss reduction