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Developing an Optimal Algorithm for State Estimation in Active Distribution Systems based on Cost-Worth Analysis
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firuzabad, Mahmoud (Supervisor)
Abstract
Nowadays, power systems are facing significant changes in traditional network operation and planning approaches with the introduction of distributed generation energy sources and increasing concerns about environmental issues. On the other hand, the Distribution Management System (DMS) in the current situation with low levels of observability and automation, controls and monitors the distribution network, which will not meet the challenges of the Active Distribution Network (ADN). For this purpose, in the first part of this dissertation, considering that the supply of network loads is important from the operator and distribution network management point of view and the voltage range and...
Distributed Encoding System in the Presence of Adversarial Sources
, Ph.D. Dissertation Sharif University of Technology ; Maddah Ali, Mohammad Ali (Supervisor)
Abstract
In communications systems, coding is used to combat channel errors. The redundancy introduced by coding enables the detection and/or correction of errors occurring in the channel. In addition to communications systems, coding is also beneficial in various other systems such as distributed storage systems and blockchain systems to cope with node failures, data erasures, and adversarial behaviors attempting to modify information. In existing applications of coding, it is generally assumed that the encoding operation is performed correctly and without errors, and errors are applied to the encoded data. In recent years, applications have emerged where the assumption of error-free encoding is not...
Distribution network reliability improvements in presence of demand response
, Article IET Generation, Transmission and Distribution ; Vol. 8, issue. 12 , 2014 , p. 2027-2035 ; ISSN: 17518687 ; Degefa, M.Z ; Lehtonen, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
Abstract
Demand response (DR) as a key integral part of the future smart grid is gaining a great and still growing focus of attention in nowadays electric power industries. However, many potential benefits of DR, although they have been envisioned to be significant, have not been yet thoroughly and quantitatively investigated. DR provides network operators with the opportunity to mitigate operational limit violations by load modification in place of load shedding when network reliability is jeopardised. This paper aims to comprehensively assess the potential impacts of DR on major attributes of service reliability in a residential distribution network. For doing so, firstly, load profiles for major...
Investigation of the current maintenance experiences in power distribution utulities of Iran
, Article IET Conference Publications ; Vol. 2013, issue. 615 CP , 2013 ; ISBN: 9781850000000 ; Fotuhi-Firuzabad, M ; Moghimi, S. E ; Khomami, M. S ; Sharif University of Technology
Abstract
This paper presents the most frequently used maintenance concerns and challenges in distribution utilities of Iran. A questionnaire is devised and distributed among the maintenance experts in more than 30 distribution utilities all over Iran and their responses have been taken under consideration in this paper. The aim is to get the most out of the successful maintenance experiences within the utilities, to find the solutions on the current common challenges on the distribution system maintenance policies, and eventually to enlighten the way on the transition to the more efficient maintenance approaches such as reliability-centered maintenance (RCM) in distribution systems
Investigating the impacts of plug-in hybrid electric vehicles on distribution congestion
, Article IET Conference Publications ; Vol. 2013, issue. 615 CP , 2013 ; ISBN: 9781850000000 ; Fotuhi-Firuzabad, M ; Rastegar, M ; Sharif University of Technology
Abstract
Smart grids are envisioned to support large penetrations of electrical vehicles driven by economical and environmental signals. Nevertheless, distribution system operators are becoming concerned about distribution congestion that may occur in the network with multiple domestic plug-in hybrid electric vehicles (PHEVs) charging. Therefore, investigating the impacts of high PHEV penetration levels on the performance of distribution networks seems to be essential for system operators and planners. Doing so, in this paper, PHEV characteristics are precisely extracted from valid published reports and surveys. Accordingly, a comprehensive model for investigating the impacts of different PHEV...
Investigating the impacts of plug-in hybrid electric vehicles on power distribution systems
, Article IEEE Transactions on Smart Grid ; Vol. 4, issue. 3 , 2013 , p. 1351-1360 ; ISSN: 19493053 ; Fotuhi-Firuzabad, M ; Rastegar, M ; Sharif University of Technology
Abstract
Despite the economic and environmental advantages of plug-in hybrid electric vehicles (PHEVs), the increased utilization of PHEVs brings up new concerns for power distribution system decision makers. Impacts of PHEVs on distribution networks, although have been proven to be noticeable, have not been thoroughly investigated for future years. In this paper, a comprehensive model is proposed to study the PHEV impacts on residential distribution systems. In so doing, PHEV fundamental characteristics, i.e., PHEV battery capacity, PHEV state of charge (SOC), and PHEV energy consumption in daily trips, are accurately modeled. As some of these effective characteristics depend on vehicle owner's...
Impacts of fault diagnosis schemes on distribution system reliability
, Article IEEE Transactions on Smart Grid ; Vol. 3, issue. 2 , 2012 , p. 720-727 ; ISSN: 19493053 ; Lehtonen, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
Abstract
Design and development of fault diagnosis schemes (FDS) for electric power distribution systems are major steps in realizing the self-healing function of a smart distribution grid. The application of the FDS in the electric power distribution systems is mainly aimed at precise detecting and locating of the deteriorated components, thereby enhancing the quality and reliability of the electric power delivered to the customers. The impacts of two types of the FDS on distribution system reliability are compared and presented in this paper. The first type is a representative of the FDS which diagnoses the deteriorated components after their failing. However, the second type is a representative of...
Distribution loss allocation for radial systems including dgs
, Article IEEE Transactions on Power Delivery ; Vol. 29, issue. 1 , 2014 , pp. 72-80 ; ISSN: 08858977 ; Mahmoodzadeh, Z ; Ehsan, M ; Sharif University of Technology
Abstract
Due to the liberalization of the electricity market and the introduction of distributed generation (DG), the importance of distribution loss allocation (LA) has increased. This paper presents a new method for distribution power LA in radial systems. The proposed method, which is based on the results of power flow and considers active and reactive power flows of lines for LA, is composed of three steps. In the first step, starting from the source nodes (i.e., the nodes whose generation is more than their load), the power loss allocated to all nodes is calculated and then the power loss allocated to the loads connected to each node is obtained. In the next step, the total power loss is...
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 ; Davari-Nejad, E ; Kamyab, F ; Vakilian, M ; Haghifam, M. R ; Sharif University of Technology
Abstract
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...
Evaluation of intelligent distribution network response to plug-in hybrid electric vehicles
, Article 2013 IEEE Grenoble Conference PowerTech, POWERTECH 2013 ; June , 2013 ; 9781467356695 (ISBN) ; Maani, A ; Ranjbar, A. M ; Sharif University of Technology
2013
Abstract
Plug-in Hybrid Electric Vehicles (PHEV) have the potential to limit emissions and reduce the cost of transportation. Although wide scale adoption of plug-in vehicles is still a few years away, politicians, electric utilities, and auto companies are eagerly awaiting the opportunities that may arise from reduction of emissions and gasoline and oil consumption, new services and increased revenues, and new markets that would create new jobs. For consumers, plug-in vehicles will significantly lower operational costs when compared with traditional gasoline cars. The savings are potentially high, in average, as electricity cost mile work out to about one forth of gasoline. But it is noticeable to...
Application of pulse closing technology for automatic loop restoration
, Article IET Conference Publications ; Volume 2013, Issue 615 CP , 2013 ; 9781849197328 (ISBN) ; Millar, R. J ; Lehtonen, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
2013
Abstract
This paper aims to quantitatively evaluate and compare the reliability impact of employing an automatic loop restoration scheme in a typical distribution system, with and without pulse closing technology. Sustained interruptions, momentary interruptions and voltage sags are the three major attributes of the service reliability that are taken into account in the reliability case studies
Investigation of the current maintenance experiences in power distribution utulities of Iran
, Article IET Conference Publications, Stockholm,Sweden ; Volume 2013, Issue 615 CP , June , 2013 , Page(s):1 - 4 ; 9781849197328 (ISBN) ; Fotuhi-Firuzabad, M ; Moghimi, S. E ; Khomami, M. S ; Sharif University of Technology
2013
Abstract
This paper presents the most frequently used maintenance concerns and challenges in distribution utilities of Iran. A questionnaire is devised and distributed among the maintenance experts in more than 30 distribution utilities all over Iran and their responses have been taken under consideration in this paper. The aim is to get the most out of the successful maintenance experiences within the utilities, to find the solutions on the current common challenges on the distribution system maintenance policies, and eventually to enlighten the way on the transition to the more efficient maintenance approaches such as reliability-centered maintenance (RCM) in distribution systems
GoSCAN: Decentralized scalable data clustering
, Article Computing ; Volume 95, Issue 9 , 2013 , Pages 759-784 ; 0010485X (ISSN) ; Habibi, J ; Voulgaris, S ; Van Steen, M ; Sharif University of Technology
2013
Abstract
Identifying clusters is an important aspect of analyzing large datasets. Clustering algorithms classically require access to the complete dataset. However, as huge amounts of data are increasingly originating from multiple, dispersed sources in distributed systems, alternative solutions are required. Furthermore, data and network dynamicity in a distributed setting demand adaptable clustering solutions that offer accurate clustering models at a reasonable pace. In this paper, we propose GoScan, a fully decentralized density-based clustering algorithm which is capable of clustering dynamic and distributed datasets without requiring central control or message flooding. We identify two major...
Impacts of fault diagnosis schemes on distribution system reliability
, Article IEEE Transactions on Smart Grid ; Volume 3, Issue 2 , February , 2012 , Pages 720-727 ; 19493053 (ISSN) ; Lehtonen, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
2012
Abstract
Design and development of fault diagnosis schemes (FDS) for electric power distribution systems are major steps in realizing the self-healing function of a smart distribution grid. The application of the FDS in the electric power distribution systems is mainly aimed at precise detecting and locating of the deteriorated components, thereby enhancing the quality and reliability of the electric power delivered to the customers. The impacts of two types of the FDS on distribution system reliability are compared and presented in this paper. The first type is a representative of the FDS which diagnoses the deteriorated components after their failing. However, the second type is a representative of...
Multi-level authorisation model and framework for distributed semantic-aware environments
, Article IET Information Security ; Volume 4, Issue 4 , 2010 , Pages 301-321 ; 17518709 (ISSN) ; Jalili, R ; Sharif University of Technology
Abstract
Semantic technology is widely used in distributed computational environments to increase interoperability and machine readability of information through giving semantics to the underlying information and resources. Semantic-awareness, distribution and interoperability of new generation of distributed systems demand an authorisation model and framework that satisfies essential authorisation requirements of such environments. In this study, the authors propose an authorisation model and framework based on multi-security-domain architecture for distributed semantic-aware environments. The proposed framework is founded based on the MA(DL)2 logic, which enables policy specification and inference...
Symmetry and partial order reduction techniques in model checking Rebeca
, Article Acta Informatica ; Volume 47, Issue 1 , 2010 , Pages 33-66 ; 00015903 (ISSN) ; Sirjani, M ; Mousavi, M.R ; Khamespanah, E ; Movaghar, A ; Sharif University of Technology
2010
Abstract
Rebeca is an actor-based language with formal semantics which is suitable for modeling concurrent and distributed systems and protocols. Due to its object model, partial order and symmetry detection and reduction techniques can be efficiently applied to dynamic Rebeca models. We present two approaches for detecting symmetry in Rebeca models: One that detects symmetry in the topology of inter-connections among objects and another one which exploits specific data structures to reflect internal symmetry in the internal structure of an object. The former approach is novel in that it does not require any input from the modeler and can deal with the dynamic changes of topology. This approach is...
Estimating parameters with pre-specified accuracies in distributed parameter systems using optimal experiment design
, Article International Journal of Control ; Volume 89, Issue 8 , 2016 , Pages 1533-1553 ; 00207179 (ISSN) ; Bombois, X ; Mansoori, M ; Van Den Hof, P. M. J ; Sharif University of Technology
Taylor and Francis Ltd
Abstract
Estimation of physical parameters in dynamical systems driven by linear partial differential equations is an important problem. In this paper, we introduce the least costly experiment design framework for these systems. It enables parameter estimation with an accuracy that is specified by the experimenter prior to the identification experiment, while at the same time minimising the cost of the experiment. We show how to adapt the classical framework for these systems and take into account scaling and stability issues. We also introduce a progressive subdivision algorithm that further generalises the experiment design framework in the sense that it returns the lowest cost by finding the...
Impacts of remote control switch malfunction on distribution system reliability
, Article IEEE Transactions on Power Systems ; Volume 32, Issue 2 , 2017 , Pages 1572-1573 ; 08858950 (ISSN) ; Farajollahi, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Remote control switches (RCSs) are often assumed to be fully reliable in reliability and cost/worth analyses. This assumption, however, overestimates their merits, thereby misguiding network owners about their optimal implementation. This letter extends the current reliability evaluation procedure to incorporate probability of RCS malfunctions. Then, the extended procedure is applied to a network equipped with a few RCSs. The numerical studies reveal that RCS malfunctions degrade their worth, which may even affect their optimal number and locations. © 1969-2012 IEEE
Enhanced control of grid forming VSCs in a micro-grid system under unbalanced conditions
, Article 9th Annual International Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2018, 13 February 2018 through 15 February 2018 ; Volume 2018-January , April , 2018 , Pages 380-385 ; 9781538646977 (ISBN) ; Mokhtari, H ; Ghasemi, M. A ; SHarif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Due to the technical advances in power electronic industry, employing inverter-based distributed energy resources (IBDERs) are increased in electric power systems. Distributed generators (DGs) with the rating capacity of few megawatts are commonly connected to the distribution level of power systems which are inherently unbalanced. A cluster of IBDERs and loads form a small-scale grid called microgrid (MG) which can operate independent of the main grid. In a MG, grid forming voltage source converters (VSCs) are used to control the voltages and frequency of the MG. However, grid forming VSCs with conventional control schemes cannot do this task properly when the MG is unbalanced. In this...
Optimal switch placement in distribution systems using trinary particle swarm optimization algorithm
, Article IEEE Transactions on Power Delivery ; Volume 23, Issue 1 , 2008 , Pages 271-279 ; 08858977 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
2008
Abstract
Achieving high-distribution reliability levels and concurrently minimizing capital costs can be considered as the main issues in distribution system optimization. Determination of the optimum number and location of switches in distribution system automation is an important issue from the reliability and economical points of view. In this paper, a novel three-state approach inspired from the discrete version of a powerful heuristic algorithm, particle swarm optimization, is developed and presented to determine the optimum number and locations of two types of switches (sectionalizers and breakers) in radial distribution systems. The novelty of the proposed algorithm is to simultaneously...