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An analytical method to consider DG impacts on distribution system reliability
, Article 2005 IEEE/PES Transmission and DistributionConference and Exhibition - Asia and Pacific, Dalian, 15 August 2005 through 18 August 2005 ; Volume 2005 , 2005 , Pages 1-6 ; 0780391144 (ISBN); 9780780391147 (ISBN) ; Rajabi Ghahnavie, A ; Sharif University of Technology
2005
Abstract
Distributed generation is expected to play an increasing role in emerging power systems. They use different type of resources and technologies to serve energy to power system. DG has positive and negative effects for both the utilities and customers. System and load point reliability indices are normally improved if DG is installed in a distribution network. On the other hand, DG has some specific characteristics which distinguish it from conventional generating units. Therefore, they should not be treated as conventional generating units to perform reliability evaluation. An appropriate model is required to be developed in order to assess impacts of DG on reliability indices. Impacts of DG...
Reliability Assessment of DSSC devices and Optimal Placement of them with the aim of Enhancing Power System Loadability and Reliability
, M.Sc. Thesis Sharif University of Technology ; Fotuhi-Firuzabad, Mahmoud (Supervisor)
Abstract
One of the important problems in fulfilling the consumers' power demand that has been especially intensified after restructuring is transmission line congestion. To solve this problem, either new transmission lines should be constructed or the existing transmission lines should be better utilized. Construction of new transmission lines is both expensive and time consuming. Therefore, it is usually better to enhance the utilization of the existing transmission assets. FACTS devices have been introduced over the past decades to enhance power systems operation. However, wide scale deployment of them has not occurred yet due to their high initial investment cost and some other problems. In order...
Impact of penalty-reward mechanism on the performance of electric distribution systems and regulator budget
, Article IET Generation, Transmission and Distribution ; Vol. 4, issue. 7 , 2010 , p. 770-779 ; ISSN: 17518687 ; Fotuhi-Firuzabad, M ; Sharif University of Technology
Abstract
As a part of the ongoing debate about competition in the electricity industry, regulators are increasingly considering performance-based regulation (PBR) as an alternative to improve the service quality. The fundamental principle behind PBR is that good performance should lead to higher profits, and poor performance should result in lower profits. A penalty-reward structure (PRS) in a PBR mechanism can enhance utility performance to align utility interests with customer's interests. During the implementation of PBR, regulators should spend or receive money to reward good performed utilities or penalised poor performed utilities, respectively. A technique is proposed, in this study, to not...
Sensitivity measures for optimal mitigation of risk and reduction of model uncertainty
, Article Reliability Engineering and System Safety ; Volume 117 , 2013 , Pages 9-20 ; 09518320 (ISSN) ; Haukaas, T ; Sharif University of Technology
2013
Abstract
This paper presents a new set of reliability sensitivity measures. The purpose is to identify the optimal manner in which to mitigate risk to civil infrastructure, and reduce model uncertainty in order to improve risk estimates. Three measures are presented. One identifies the infrastructure components that should be prioritized for retrofit. Another measure identifies the infrastructure that should be prioritized for more refined modeling. The third measure identifies the models that should be prioritized in research to improve models, for example by gathering new data. The developments are presented in the context of a region with 622 buildings that are subjected to seismicity from several...
Seismic risk analysis with reliability methods, part I: Models
, Article Structural Safety ; Volume 42 , 2013 , Pages 54-62 ; 01674730 (ISSN) ; Haukaas, T ; Sharif University of Technology
2013
Abstract
A library of probabilistic models for prediction of seismic risk is presented. The models are specifically intended for use with reliability methods to compute event probabilities, such as seismic loss probabilities. Several models are presented here for the first time. In particular, new and generic models are proposed for earthquake location, regional loss, building response, building damage, and building loss. Each model is presented with an explanation of its development and a discussion of its predictions. In addition, models from the literature are " smoothed" to make them amenable to reliability analysis. The models are implemented in a new computer program that is tailored for...
FOMA: Flexible overlay multi-path data aggregation in wireless sensor networks
, Article Proceedings - IEEE Symposium on Computers and Communications, 1 July 2012 through 4 July 2012 ; July , 2012 , Pages 000508-000511 ; 15301346 (ISSN) ; 9781467327121 (ISBN) ; Yousefi, H ; Hemmatyar, A. M. A ; Movaghar, A ; Sharif University of Technology
IEEE
2012
Abstract
Data aggregation is an efficient method to conserve energy by reducing packet transmissions in WSNs. However, providing end-to-end data reliability is a major challenge when the network uses data aggregation. In this case, a packet loss can miss a complete subtree of values, thus greatly affecting the final results. Data transmission in multiple paths can tolerate this problem, but it may incur some computation errors for duplicate-sensitive aggregates. In this paper, we propose a Flexible Overlay Multi-path data Aggregation protocol (FOMA) which uses the available path redundancy to deliver a correct aggregate result to the sink with high reliability in an energy-efficient manner. It...
Fast reliability analysis method for sequential logic circuits
, Article Proceedings - ICSEng 2011: International Conference on Systems Engineering, 16 August 2011 through 18 August 2011, Las Vegas, NV ; 2011 , Pages 352-356 ; 9780769544953 (ISBN) ; Jahanirad, H ; Attarsharghi, P ; Sharif University of Technology
2011
Abstract
Reliability analysis of combinational logic circuits using error probabilities methods, such as PTM, has been widely developed and used in literature. However, using these methods for reliability analysis of sequential logic circuits will lead to inaccurate results, because of existence of loops in their architecture. In this paper a new method is proposed based on converting the sequential circuit to a secondary combinational circuit and applying an iterative reliability analysis to the resulting configuration. Experimental results demonstrate good accuracy levels for this method
A new reward-penalty mechanism for distribution companies based on concept of competition
, Article IEEE PES Innovative Smart Grid Technologies Conference Europe, 12 October 2014 through 15 October 2014 ; Volume 2015-January, Issue January , October , 2015 ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Ozdemir, A ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
In this paper, a new method for designing procedure of Reward-Penalty Scheme (RPS) in distribution system is proposed. Being fair and adoptable in viewpoint of distribution companies (DisCos) are main superiorities of the proposed RPS. Established based on concept of the Yardstick theory, its application can ensure regulators that a perfect competition will be created between DisCos to improve the service reliability. Also, such a regulation scheme can be a key for power system decision makers in order to prevent the DisCos from decreasing service reliability. Aimed to reach a fair mechanism, the proposed RPS rewards/penalizes the DisCos only compared with the other ones owning similar...
Impact of penalty-reward mechanism on the performance of electric distribution systems and regulator budget
, Article IET Generation, Transmission and Distribution ; Volume 4, Issue 7 , 2010 , Pages 770-779 ; 17518687 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
2010
Abstract
As a part of the ongoing debate about competition in the electricity industry, regulators are increasingly considering performance-based regulation (PBR) as an alternative to improve the service quality. The fundamental principle behind PBR is that good performance should lead to higher profits, and poor performance should result in lower profits. A penalty-reward structure (PRS) in a PBR mechanism can enhance utility performance to align utility interests with customer's interests. During the implementation of PBR, regulators should spend or receive money to reward good performed utilities or penalised poor performed utilities, respectively. A technique is proposed, in this study, to not...
A low-overhead and reliable switch architecture for Network-on-Chips
, Article Integration, the VLSI Journal ; Volume 43, Issue 3 , June , 2010 , Pages 268-278 ; 01679260 (ISSN) ; Miremadi, S. G ; Fazeli, M ; Sharif University of Technology
2010
Abstract
This paper proposes and evaluates Low-overhead, Reliable Switch (LRS) architecture to enhance the reliability of Network-on-Chips (NoCs). The proposed switch architecture exploits information and hardware redundancies to eliminate retransmission of faulty flits. The LRS architecture creates a redundant copy of each newly received flit and stores the redundant flit in a duplicated flit buffer that is associated with the incoming channel of the flit. Flit buffers in the LRS are equipped with information redundancy to detect probable bit flip errors. When an error is detected in a flit buffer, its duplicated buffer is used to recover the correct value of the flit. In this way, the propagation...
A comprehensive scheme for reliability centered maintenance in power distribution systems - Part I: methodology
, Article IEEE Transactions on Power Delivery ; Volume 28, Issue 2 , 2013 , Pages 761-770 ; 08858977 (ISSN) ; Fotuhi Firuzabad, M ; Aminifar, F ; Billinton, R ; Sharif University of Technology
Abstract
Although reliability-centered maintenance (RCM) has proven its noticeable merits in many industries, has not been yet furnished with efficient analytical methods in the power engineering context. The first of this two-paper set presents a practical framework by which the RCM procedure can be implemented in power distribution systems. The proposed algorithm consists of three main stages. The prerequisites of the analysis are outlined in the first stage. In the second stage, an approach is developed to identify the network's critical components, from the reliability point of view. Having practically modeled the components' failure rates, an efficient cost/benefit evaluation approach is then...
Fault-tolerant DC power distribution unit based on nonexclusive redundant modules
, Article IEEE Transactions on Industrial Electronics ; Volume 63, Issue 11 , 2016 , Pages 6801-6811 ; 02780046 (ISSN) ; Parvari, R ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
Reliability of the power distribution unit (PDU) is very important in electrical systems. Since any failure in this unit leads to system failure. A commonly used method for increasing the reliability of a dc PDU is using the redundant modules. If a fault occurs in a voltage regulator of PDU, it is replaced by its redundant module. In conventional redundancy, each dc voltage regulator has its exclusive redundant modules. Therefore, if both a regulator and its redundant modules fail, the system is stopped. It is an important drawback since the exclusive redundant modules of other voltage regulators may not be used, but, the PDU cannot use them instead of faulty regulators. In this paper, the...
Resilience of civil infrastructure by optimal risk mitigation
, Article Scientia Iranica ; Volume 23, Issue 5 , 2016 , Pages 1961-1974 ; 10263098 (ISSN) ; Sharif University of Technology
Sharif University of Technology
Abstract
This paper puts forward a framework for optimal mitigation of regional risk to enhance the resilience of civil infrastructure. To meet this objective, probabilistic models, methods, and software are developed and applied. The work is conducted within a new reliability-based approach, in which reliability methods compute risk. This contrasts several contemporary approaches for risk analysis. Risk, in this context, denotes the probability of exceeding monetary loss. Evaluating such probabilities requires probabilistic models for hazards, response, damage, and loss. This motivates the following contributions in this paper. First, a new computer program is developed that is tailored to conduct...
RDTP: reliable data transport protocol in wireless sensor networks
, Article Telecommunication Systems ; Volume 62, Issue 3 , 2016 , Pages 611-623 ; 10184864 (ISSN) ; Movaghar, A ; Sabaei, M ; Sharif University of Technology
Springer New York LLC
Abstract
The paper deals with a new reliable data transport protocol for wireless sensor networks, referred as RDTP. One of the most prominent challenges in wireless sensor networks is reliable transport of data from sensor nodes to sink node. For designing protocols for such networks hardware, some constraining factors associated with energy and processing power must be taken into consideration. There are two generic methods, ARQ and FEC to achieve reliable data transport. Here, a reliable data transport protocol for wireless sensor networks is proposed, in which an efficient moduli set in redundant residue number system has been employed. The modulus set is exploited as a means for adding...
Operational reliability studies of power systems in presence of energy storage systems
, Article IEEE Transactions on Power Systems ; 2017 ; 08858950 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Abstract
This paper mainly focuses on operational reliability studies of modern power systems taking into consideration the effects of energy storage systems (ESSs). The aim is to develop a new evaluation tool to assess the effects of different factors such as penetration rate, operational strategies and capacities of the ESSs in determining the role of these systems as an operating reserve resource. In this regard, at first, some modifications are made to the PJM method aimed to precisely model the short-term variability in output generation of wind farms in reliability studies. Then, this algorithm is employed to examine the effects of ESSs operating strategies in operational reliability level of...
A unit commitment for electricity market participation of wind farms
, Article 2017 IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2017, 23 April 2017 through 26 April 2017 ; 2017 ; 9781538628904 (ISBN) ; Hosseini, S. H ; Dorostkar Ghamsari, M ; Sharif University of Technology
Abstract
In this paper a reliability, emission, and network security constrained unit commitment (UC) with the focus on wind power integration is formulated. It is shown that clearing both energy and spinning reserve markets taking into account network constraints provides a reliable and economic solution for day-ahead operation planning of a power system with a significant amount of thermal and wind power in the generation portfolio. The developed UC is formulated and implemented in MATLAB. The IEEE 24-Bus Reliability Test System (RTS) is used to verify the UC method by simulation. © 2017 IEEE
Reliability analysis of rotating cracked blade using modal data
, Article 2017 International Conference on Mechanical, System and Control Engineering, ICMSC 2017, 19 May 2017 through 21 May 2017 ; 2017 , Pages 78-84 ; 9781509065295 (ISBN) ; Zabihollah, A ; Behzad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
This paper deals with vibrational behaviors of blades with cracks which are key components in rotating machines. However, since modelling and analysis of real blade is a complex problem, a simplified cantilever beam with both chordwise (in X-Y plane) and flapwise (in X-Z plane) motion are modeled instead. Finite Element Method (FEM) is used to model beam and to investigate its natural frequencies with a crack. Finally a limit function using modal data is developed and reliability analysis of beam model is performed. © 2017 IEEE
Reliability assessment of protective relays in harmonic-polluted power systems
, Article IEEE Transactions on Power Delivery ; Volume 32, Issue 1 , 2017 , Pages 556-564 ; 08858977 (ISSN) ; Anders, G. J ; Fotuhi Firuzabad, M ; Farzin, H ; Aminifar, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Proliferation of distributed generations (DGs) and power-electronics-based loads is bringing about more harmonic-polluted power signals. While some failures may occur as a consequence of nonsinusoidal current or voltage waveforms, existing reliability models of protection relays have not taken the harmonic-related failures into consideration. This paper develops a comprehensive Markov reliability model to categorize the possible functional states of a component, say a transmission line, protected by a relay, operating in a harmonic-polluted environment. In order to make the proposed model practically tractable, it is further simplified in two ways, through merging the states of the same...
Generalized analytical approach to assess reliability of renewable-based energy hubs
, Article IEEE Transactions on Power Systems ; Volume 32, Issue 1 , 2017 , Pages 368-377 ; 08858950 (ISSN) ; Farzin, H ; Fotuhi Firuzabad, M ; Amrollahi, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
This paper proposes a generalized analytical approach to evaluate the reliability of active distribution networks. The studies are implemented in the context of renewable-based energy hubs. The reliability of energy demands is determined as a function of reliability characteristics of energy hub input resources and converters as well as hub operating strategies. The framework proposed in this paper involves the main attributes of different distributed generation technologies as well as vehicle-to-grid (V2G)-capable vehicles in the reliability studies. Dealing with the uncertainty in energy services provided by the wind turbine output generation and V2G programs, efficient probabilistic...
Operational reliability studies of power systems in the presence of energy storage systems
, Article IEEE Transactions on Power Systems ; Volume 33, Issue 4 , July , 2018 , Pages 3691-3700 ; 08858950 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper mainly focuses on operational reliability studies of modern power systems taking into consideration the effects of energy storage systems (ESSs). The aim is to develop a new evaluation tool to assess the effects of different factors such as penetration rate, operational strategies, and capacities of the ESSs in determining the role of these systems as a source of operating reserve. In this regard, at first, some modifications are made to the Pennsylvania-New Jersey-Maryland (PJM) method aimed to precisely model the short-term variability in output generation of wind farms in reliability studies. Then, this algorithm is employed to examine the effects of ESSs operating strategies...