Search for: loss-reductions
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    Loss Reduction Feasibility Study in Distribution Network

    , M.Sc. Thesis Sharif University of Technology Fazeli, Faezeh (Author) ; Safaieh, Mohammad Reza (Supervisor)
    Regarding complexity and wide range use of distribution network structures, loss reduction is possible in case of complete knowledge and suitable approaches. Loss reduction not only can grow GDP but also can improve economic growth. It should have schedule and plan wisely. Thus, in this research, first a region called Yusef Abad in Tehran was selected then the network was assessed completely. During the assessment, the research team determines causes of energy loss and load loss and then measured amount of each one. Then, the loss share of each element of the network determined. Elements of the network consist of transformers, conductors and meters. Then possible solutions for loss reduction... 

    Application of a Modified NSGA Method for Multi-Objective Static Distributed Generation Planning

    , Article Arabian Journal for Science and Engineering ; Volume 36, Issue 5 , 2011 , Pages 809-825 ; 13198025 (ISSN) Soroudi, A ; Ehsan, M ; Sharif University of Technology
    The characteristics of integrating distributed generation (DG) in a distribution network have changed. These electrical resources are used as an alternative energy source to the main grid. The technical and economical benefits of such units are achieved only when they are optimally sized and placed in the network. In this paper, a static mixed integer non-linear model for distributed generation planning is defined and solved using a modified NSGA method (Non-dominated Sorting Genetic Algorithm). Different DG technologies are considered and the objective functions for minimization are defined as the total active loss, investment and operational costs, and environmental pollution. The method... 

    Modeling of Static Series Voltage Regulator (SSVR) in distribution systems for voltage improvement and loss reduction

    , Article Leonardo Electronic Journal of Practices and Technologies ; Volume 7, Issue 12 , 2008 , Pages 61-82 ; 15831078 (ISSN) Hosseini, M ; Shayanfar, H. A ; Fotuhi Firuzabad, M ; Sharif University of Technology
    This paper introduces the modeling of Static Series Voltage Regulator (SSVR) in the load flow calculations for steady-state voltage compensation and loss reduction. For this approach, an accurate model for SSVR is derived to use in load flow calculations. The rating of this device as well as direction of required reactive power injection to compensate voltage to the desired value (1p.u.) is derived, discussed analytically, and mathematically using phasor diagram method. Since performance of SSVR varies when it reaches to its maximum capacity, modeling of SSVR in its maximum rating of reactive power injection is derived. The validity of the proposed model is examined using two standard... 

    Determining and optimizing power loss reduction in distribution feeders due to Distributed generation

    , Article 2006 IEEE PES Power Systems Conference and Exposition, PSCE 2006, Atlanta, GA, 29 October 2006 through 1 November 2006 ; 2006 , Pages 1914-1918 ; 142440178X (ISBN); 9781424401789 (ISBN) Honarvar Nazari, M ; Parniani, M ; Sharif University of Technology
    One of the beneficial impacts of Distributed generation (DG) units on electrical network is power loss reduction in the distribution feeder on which DG is located. In this paper the effect of DG on power losses of a distribution feeder with a combination of uniformly distributed and lumped loads is investigated, and a mathematical model of power loss reduction as a function of DG and the feeder parameters is extracted. Then, based on the derived formula, optimum conditions of utilizing and locating the DG units are obtained. © 2006 IEEE  

    Design of Medium Voltage Cascaded H Bridge Multilevel Inverter with Reliability Consideration

    , M.Sc. Thesis Sharif University of Technology Balador, Ayoub (Author) ; Zolghadri, Mohammad Reza (Supervisor)
    Today, with the development of power electronics and the emergence of various multilevel converters, possibility of operation at the voltage and powers higher than the rated value of components is provided. The reliability of these converters due to their high power is important. In this project, design of multilevel inverter with cascaded H-bridge structure have been studied for a medium voltage and high power 3.3 KV, 1MVA application, due to its advantages over other structures. This converter is composed of several cascaded low voltage full-bridge cells. Therefore, the converter is composed of many semiconductor elements that the reliability of them depends on the physical stresses such... 

    Investigating the Role of Knowledge Management Processes in Reducing Waste

    , M.Sc. Thesis Sharif University of Technology Maleki, Hoomaan (Author) ; Houshmand, Mahmoud (Supervisor)
    This research investigates the role and effects of knowledge management processes in reducing both cost and waste at the Dorsa Leather Goods Company. This methodology is based on both qualitative and quantitative research methods. The qualitative stage consists of analysis of past research and interviews with all levels of management. This stage leads to identifying knowledge management factors, effective in reducing cost and waste. Subsequently, we identified five main aspects encompassing all the effective aforementioned factors. These aspects are strategic, organizational structure, human resource, organizational culture, and technological infrastructure.The quantitative stage is... 

    Effects of Optimal DG Operation Point on Loss Reduction due to Network Reconfiguration

    , M.Sc. Thesis Sharif University of Technology Seyyed Mahdavi, Saeed (Author) ; Abbaspur Tehrani Fard, Ali (Supervisor)
    During the last few years, utilization of distributed generation (DG) in power systems has been widely increased. This trend has magnified studying the effects and impacts of DG on such systems. One of the benefits of DGs in a power system is loss reduction. If determining DG size and place is done properly, the loss of the network can be minimized. Another way of reducing loss in distribution network is by reconfiguring the network. During the reconfiguration, constraints like being radial, avoiding load isolation as well as voltage/current limitations must be taken into consideration. Taking these constraints into account makes reconfiguration an optimization problem. In this project, the... 

    Reconfiguration and Capcitor Placement in Distribution Systems for Loss Reduction and Reliability Enhancement

    , M.Sc. Thesis Sharif University of Technology Rezaei, Pooya (Author) ; Vakilian, Mehdi (Supervisor)
    Capacitor setting and reconfiguration are of main means of loss reduction and voltage profile improvement in distribution system operation. Cooperation between these two strategies can effectively minimize power losses in distribution system automation. Also, from the medium and long term viewpoint, capacitor placement and reconfiguration can be used for loss reduction and reliability enhancement. In this section, the sum of losses cost, capacitor investment cost and reliability cost should be minimized. Regarding the need to solve two non-linear combinatorial optimization problems simultaneously, metaheuristic algorithms are used in this thesis. Specifically, Elitist Genetic Algorithm,... 

    A novel simultaneous reconfiguration and capacitor switching method to improve distribution networks operation

    , Article 2014 14th International Conference on Environment and Electrical Engineering, EEEIC 2014 - Conference Proceedings ; May , 2014 , pp. 295-300 ; ISBN: 9781479946617 Ameli, A ; Davari-Nejad, E ; Kamyab, F ; Vakilian, M ; Haghifam, M. R ; Sharif University of Technology
    Due to the important role that distribution systems play in quality of power delivered to the customers, there has always been a great deal of interest in investigating different methods of efficiency enhancement for these networks. Two of these methods are Feeder Reconfiguration (FR) and Capacitor Allocation (CA); both have been widely employed to reduce losses and improve several other operational characteristics in electrical power distribution systems. As in FR process the topology of the network changes, it is necessary to change some previous settings; for instance: the capacity of capacitor banks in service in each bus, after each reconfiguration process. This is due to the fact that... 

    Reconfiguration and capacitor placement in radial distribution systems for loss reduction and reliability enhancement

    , Article 2011 16th International Conference on Intelligent System Applications to Power Systems, ISAP 2011 ; 2011 Rezaei, P ; Vakilian, M ; Hajipour, E ; Sharif University of Technology
    This paper applies different approaches to solve network reconfiguration and capacitor placement/setting problem. First, reconfiguration and capacitor placement is solved for power loss minimization. Second, medium and long-term planning perspective is considered for the problem which takes into account reliability cost in addition to energy losses cost. A heuristic algorithm is used in this study for reliability evaluation considering protection schemes and isolation points in the distribution network. The problems are solved by Harmony Search Algorithm, and it is shown that its performance is much more satisfactory than several other metaheuristic algorithms to solve reconfiguration and... 

    Technical and Economic Aspects of Operating of Distribution Systems in Presence of Distributed Generation Considering the Uncertainties

    , M.Sc. Thesis Sharif University of Technology Abbaskhani Davanloo, Arash (Author) ; Ehsan, Mehdi (Supervisor)
    As electric energy loss in Iran is around 31 percent and 01 percent of this loss is related to the distribution of electric energy, management and operation of distribution network is of high importance. There are different ways for operating the distribution network while decreasing the loss, such as using capacitors, tap changers, energy storing devices, distributed generations, etc. One of the most common ways is to use Network Reconfiguration. In this thesis, daily reconfiguration of a 03-kV 22-bus distribution network is investigated. The objective function consists of cost of energy loss and improvement of voltage profile. Wind turbines are used as the sources of distributed generation... 

    Discussion of "optimal reconfiguration and capacitor allocation in radial distribution systems for energy losses minimization" by L.W. de Oliveira et al., International Journal of Electrical Power and Energy Systems 32 (2010) 840-848

    , Article International Journal of Electrical Power and Energy Systems ; Volume 42, Issue 1 , November , 2012 , Pages 701- ; 01420615 (ISSN) Rezaei, P ; Vakilian, M ; Sharif University of Technology
    This article indicates the accurate method for load level calculation to solve the power flow problem when capacitor reactive power is involved. Using the correct method causes some changes in the results and conclusion stated in the discussed paper on optimal reconfiguration and capacitor placement in radial distribution systems  

    Distribution system reconfiguration for loss reduction incorporating load and renewable generation uncertainties

    , Article 2019 IEEE Texas Power and Energy Conference, TPEC 2019, 7 February 2019 through 8 February 2019 ; 2019 ; 9781538692844 (ISBN) Abbaskhani Davanloo, A ; Amini, M ; Modarresi, M. S ; Jafarishiadeh, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    A significant share of losses in power systems occurs in distribution network due to lower voltages and longer lines. On top of that, unbalanced operation causes additional losses in these networks. In recent years with the development of distributed generation connected to the distribution grid, the concern over frequency and intensity of unbalanced operation has risen. Reconfiguration of these distribution networks plays a significant role in power loss minimization and voltage quality enhancement. The uncertainty regarding grid-connected DG resources and net loads are among the critical factors that must be taken into account. To do so, in this paper a novel Fuzzy-based reconfiguration... 

    The impact of demand response programs on UPFC placement

    , Article Turkish Journal of Electrical Engineering and Computer Sciences ; Volume 27, Issue 6 , 2019 , Pages 4624-4639 ; 13000632 (ISSN) Sharifi Nasab Anari, A ; Ehsan, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Turkiye Klinikleri  2019
    Demand response (DR) and flexible AC transmission system (FACTS) devices can be effectively used for congestion management in power transmission systems. However, demand response program (DRP) implementation can itself affect the optimum location of FACTS devices, which is one of the main issues in power system planning. This paper investigates the impact of DRPs on unified power flow controller (UPFC) placement. The harmony search algorithm is employed to determine the optimum locations and parameter setting of UPFC in a long-term framework. The optimization problem is solved with different objectives including generation and congestion cost reduction, as well as loss reduction. In this... 

    Multi objective distributed generation planning using a binary particle swarm optimization method

    , Article 2008 International Conference on Genetic and Evolutionary Methods, GEM 2008, Las Vegas, NV, 14 July 2008 through 17 July 2008 ; 2008 , Pages 140-146 ; 1601320698 (ISBN); 9781601320698 (ISBN) Soroudi, A ; Ehsan, M ; Sharif University of Technology
    With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to utilization of distributed generation. Integration of DG units has been known as an alternative for distribution network reinforcement and purchasing energy from transmission network. Considering these facts, in the planning procedure of DG, determination of optimal sizing and sitting is a very important issue. This work presents a comprehensive framework for integration of distributed generations into a distribution network, regarding various technical and economical issues such as reduction of active power losses, environmental pollutions, investment and running costs while... 

    Using genetic alghoritm for distributed generation allocation to reduce losses and improve voltage profile

    , Article 42nd International Universities Power Engineering Conference, UPEC 2007, Brighton, 4 September 2007 through 6 September 2007 ; 2007 , Pages 954-959 ; 1905593368 (ISBN); 9781905593361 (ISBN) Alinejad Beromi, Y ; Sedighizadeh, M ; Bayat, M. R ; Khodayar, M. E ; Sharif University of Technology
    This paper presents a method for the optimal allocation of Distributed generation in distribution systems. In this paper, our aim would be optimal distributed generation allocation for voltage profile improvement and loss reduction in distribution network. Genetic Algorithm (GA) was used as the solving tool, which referring two determined aim; the problem is defined and objective function is introduced. Considering to fitness values sensitivity in genetic algorithm process, there is needed to apply load flow for decision-making. Load flow algorithm is combined appropriately with GA, till access to acceptable results of this operation. We used MATPOWER package for load flow algorithm and... 

    Performance improvement of mixed-flow centrifugal pumps with new impeller shrouds: Numerical and experimental investigations

    , Article Renewable Energy ; Volume 163 , 2021 , Pages 635-648 ; 09601481 (ISSN) Bozorgasareh, H ; Khalesi, J ; Jafari, M ; Gazori, H. O ; Sharif University of Technology
    Elsevier Ltd  2021
    A new impeller configuration with innovatively-designed shrouds is introduced, and its impact on the pressure head and efficiency of the semi-open centrifugal pump is explored using experimental and numerical approaches. The proposed design includes attaching specific plates called bladelets to a semi-open impeller to limit the secondary flows over the blades resulting in an increase in the pump head and efficiency. Hydraulic performance of a centrifugal pump with three different bladelets at angles of 30°, 60°, and 90° is investigated experimentally, and the results are compared to semi-open and closed impellers. The values of pressure head and efficiency of the proposed centrifugal pump... 

    Mechanically stable superhydrophobic nanostructured aluminum mesh with reduced water surface friction

    , Article Nanotechnology ; Volume 32, Issue 19 , 2021 ; 09574484 (ISSN) Taghvaei, E ; Afzali, N ; Taghvaei, N ; Moosavi, A ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Superhydrophobic surfaces demonstrate significant characteristics which make them suitable for a wide variety of applications. In this study, we propose a facile, one-step, and cost-effective anodizing scheme using aluminum nitrate/stearic acid mixture solution to create a superhydrophobic surface on an aluminum mesh. The surface outperforms the surface anodized by the widely used oxalic acid solution in terms of superhydrophobicity and water-surface friction behavior. The proposed surface reduced the friction by 11% on average respective to the surface prepared by oxalic acid. The durability of the introduced superhydrophobic surface has also been investigated. The proposed surface retained... 

    , M.Sc. Thesis Sharif University of Technology Mahmoodzadeh, Zahra (Author) ; Ehsan, Mehdi (Supervisor)
    Losses are unavoidable in any parts of power systems, from generation to receiving nodes and occur in transmission and distribution networks. However, the main loss component is produced in distribution networks. Energy losses in distribution networks are about 70% of technological transport energy losses.
    Energy losses in distribution networks are an important indicator for the planning and operation of the system. A fast, reliable and accurate energy loss calculation method is required for optimal operation of the distribution networks.
    Energy loss depends on network's operating conditions. Loads values and loads factors are time variables; therefore, methods based on probability... 

    Energy Loss Reduction Through Flaring in Refineries

    , M.Sc. Thesis Sharif University of Technology Almasi Nahanjeh, Nasrin (Author) ; Sattari, Sorena (Supervisor)
    Overpressure protection and flare loading network are critical challenges faced by the Oil & Gas and chemical industries. Whether they are new facilities or aging ones, integrity management of overpressure and flaring systems remain significant throughout the life of the planet. One of the most important ways for protection of over pressure and depressurizing to flare header through pressure safety valve is implementation of safety instrument system (SIS). Application of safety instrumented systems for the process industries causes significant reduction of flaring load and loss prevention of valuable materials through increase protection layer availability and over pressure risk reduction....