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    Application of PSA Methods in the Reliability Analysis of EPSS of Busherhr NPP in case of Station Black Out

    , M.Sc. Thesis Sharif University of Technology Khorrami, Vahid (Author) ; Ghofrani, Mohammad Bagher (Supervisor)
    Abstract
    LOOP accident is one of the most important accidents in NPPS and it leads to loss of power supply of the RCP pumps which are the main pumps of primary circuit. Subsequently trip of the rector occurs. In safety analysis, concerning worst conditions, assumes that after a small period of time, main generator of plant stops working and loss of AC power supply of all power plant loads including safety systems ocures. To control of this accident, it’s necessary to startup and load backup power supply system (EDGs) for at least one safety channels, if not, the accident moves forwards and becomes S.B.O accident which is more important accident that ends to core damage because of stops working of all... 

    Designing the Structure of a PHEV Aggregator in Multi-Carrier Energy Environment

    , Ph.D. Dissertation Sharif University of Technology Moeini Aghtaie, Moein (Author) ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Fotuhi Firuzabad, Mahmoud (Supervisor)
    Abstract
    Large penetration of electric vehicles and distributed generation (DG) resources in upcoming years will change the future vision of distribution networks from some passive load points into active ones. The imposed load of electric vehicles charging has caused many new challenges in operation and planning studies of distribution network. In contrast, the abilities of electric vehicles in feeding back power into the network (V2G programs) has attracted attention from grid operators and also vehicles owners. So, the problem of managing charging and discharging behaviors of electric vehicles has been introduced as a hot research topic in recent year. This dissertation as the first effort in this... 

    Identifying and Ranking Supply Chain Risk Factors and Calculating Reliability in 3 Level Supply Chain

    , M.Sc. Thesis Sharif University of Technology Kardar Rostami, Reza (Author) ; Eshraghnia Jahromi, Abdolhamid (Supervisor)
    Abstract
    Since 1990, supply chains get affected by business environment changes and become more vulnerable. Changes such as globalization, decrease of inventory levels, out sourcing, etc. in this thesis after reviewing some paper, researches are categorized in 8 group. Then 30 risk factor identified from this papers. Because of basic differences in industries and different importance of risk factors in them, a case was studied in one industrial area and risk factors was evaluated in a two-step evaluation. Eventually some advices presented for increasing reliability for that case  

    Probabilistic Placement of Phasor Measurement Units (PMUs) for Power Network Observability

    , Ph.D. Dissertation Sharif University of Technology Aminifar, Farrokh (Author) ; Fotuhi Firuzabad, Mahmoud (Supervisor) ; Shahidehpour, Mohammad (Co-Advisor)
    Abstract
    Wide-area measurement system (WAMS), which is enabled by broad installation of phasor measurement units (PMUs), is a novel solution for the secure and reliable operation of modern power systems. The adequate number and appropriate location of PMUs has been introduced as a challenging research area in recent years. This dissertation is the first effort to assess the cost/worth analysis of WAMS design and PMU locationing in a probabilistic manner. In the studies conducted here, power network monitoring and control associated with the energy management system (EMS), among miscellaneous applications of WAMS, have been taken into consideration. First, the conventional deterministic definition of... 

    Codification of Reliability Evaluation Software in UAVs Industry

    , M.Sc. Thesis Sharif University of Technology Mirzaei, Payman (Author) ; Banazadeh, Afshin (Supervisor)
    Abstract
    In every modern society, the engineers and technical managers are in charge of planning, designing, manufacturing and utilizing the simplest products to the most complex systems. This shows the importance of reliability management in engineering systems. Inattention to the reliability of such systems leads to the difficulty or even impossibility in planning or utilizing them. Malfunction of products and systems results in disruption in different levels and can be regarded as a severe threat to society and environment.
    Therefore, consumers and general public expect products and systems to be durable, reliable and safe. Thus, the main question is how safe and how reliable the system will... 

    Security Analysis and Reliability Evaluation of Energy Internet

    , M.Sc. Thesis Sharif University of Technology Kolivandi, Morteza (Author) ; Rajabi Ghahnuyeh, Abbas (Supervisor)
    Abstract
    Due to the world's reliance on fossil fuels, the climate change situation has become more severe and has presented major challenges. One of the most promising growth avenues to address these issues in the medium to long term is widespread electrification based on renewable sources. However, this is only feasible if the energy infrastructure can support distributed and renewable energy sources without affecting the performance of the power grid. A grid is also necessary for energy systems in order to connect various technologies and guarantee proper integration of supply and demand for maximum efficiency. A novel idea called Energy Internet (EI) has been put forth to accomplish these goals,... 

    Continues Risk Assessment by Exploiting Artificial Intelligence

    , M.Sc. Thesis Sharif University of Technology Molla Mohammadi Sadafi, Amir (Author) ; Rajabi, Abbas (Supervisor) ; Rashtchian, Davoud (Supervisor)
    Abstract
    The Fourth Industrial Revolution brought about a fundamental change in the system of management and production, especially in the field of industry, which was accompanied by the development of technology in the fields of artificial intelligence, robotics, nanotechnology and biotechnology. In line with these changes, the industry needs a new method to evaluate the reliability of operational equipment using artificial intelligence and intelligent systems, which aims to optimize the balance between a variety of repair methods with the possibility of timely replacement of parts. In this new method, the life of the parts is increased and the unplanned maintenance costs and labor are reduced. One... 

    Reliability Evaluation of Smart Distribution Grids

    , Ph.D. Dissertation Sharif University of Technology Kazemi, Shahram (Author) ; Fotuhi Firouzabad, Mahmoud (Supervisor) ; Lehtonen, Matti (Supervisor)
    Abstract
    The term “Smart Grid” generally refers to a power grid equipped with the advanced technologies dedicated for purposes such as reliability improvement, ease of control and management, integrating of distributed energy resources and electricity market operations. Improving the reliability of electric power delivered to the end users is one of the main targets of employing smart grid technologies. The smart grid investments targeted for reliability improvement can be directed toward the generation, transmission or distribution system level. However, radial operating status, aging infrastructures, poor design and operation practices and high exposure to environmental conditions have caused the... 

    Evaluation of Fault Tolerance for SRAM-Based FPGAs by Fault Injection into Configuration Bits

    , M.Sc. Thesis Sharif University of Technology Abolhassani Ghazaani, Elyas (Author) ; Miremadi, Ghasem (Supervisor)
    Abstract
    Reconfiguration, short development time and low cost have made Field Programmable Gate Arrays (FPGAs) an appealing option for digital circuit designers. Meanwhile, the occurrence of Single Event Upset (SEU) in configuration memory of SRAM-based FPGAs can change the implemented design inside the FPGA chip. Assessing reliability of FPGA-based designs against pernicious effects of SEU has long been a challenge. Several approaches can be used to evaluate the reliability of a given design. One important approach is injecting fault into the configuration memory of a device.The existing fault injection frameworks are specific in the property e.g. providing speed only, neglecting other properties of... 

    Reliability and Economic Evaluation of Power System with Wind Power

    , M.Sc. Thesis Sharif University of Technology Karimi Taleb, Ali Asghar (Author) ; Oraee Mirzamani, Hashem (Supervisor)
    Abstract
    The demand for electrical energy is increasing. The main source of energy at this moment is fossil fuels. High price, great amount of pollution, uneven distribution and global warming are major disadvantages of fossil fuels. Using renewable resources can tackle these issues. Hence, the demand for renewable energy are highly increased. The wind energy is one type of renewable energy. Increasing the wind power penetration impairs the functionality of power system and causes the environmental issues. In order to have a stable power system this effect should be investigated thoroughly. Due to the inherent uncertain characteristics of wind energy, it is desirable to determine the characteristics... 

    SOYA: SSD-based RAID systems reliability simulator

    , Article 2016 International Conference on System Reliability and Science, ICSRS 2016, 15 November 2016 through 18 November 2016 ; 2017 , Pages 167-173 ; 9781509032778 (ISBN) Alinezhad Chamazcoti, S. A ; Safaei, B ; Miremadi, S. G ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2017
    Abstract
    The use of Solid State Drives (SSDs) has been increased in storage systems due to high performance and low power consumption. However, some inherent properties of SSDs result in different behavior for SSDs in comparison with Hard Disk Drives (HDDs). As an inherent property, the Bit Error Rate (BER) of SSDs increases, when the number of Program/Erase (P/E) cycles arises. This increment leads to two effects in an array of SSDs during its operation: (1) different BER on different SSDs of the system (SSD-variant BER), and (2) different BER in different time moments (time-variant BER). With respect to these two effects, the reliability evaluation of SSD-based RAIDs would be different from... 

    Review of reduction techniques in the determination of composite system adequacy equivalents

    , Article Electric Power Systems Research ; Volume 80, Issue 12 , 2010 , Pages 1385-1393 ; 03787796 (ISSN) Akhavein, A ; Fotuhi Firuzabad, M ; Billinton, R ; Farokhzad, D ; Sharif University of Technology
    2010
    Abstract
    Reliability evaluation of a large composite power system involves the consideration of numerous outage events and consequently extensive calculations. Therefore, applying justifiable simplifications such as the determination of an equivalent networks can be very useful in reliability evaluation of large systems. This paper presents a review of procedures which are directly or indirectly applicable to the determination of composite system adequacy equivalents. Following a brief discussion on the basic characteristics of the various methods, their limitations are presented. Concluding points regarding the methods and modeling schemes related to adequacy equivalent are presented at the end of... 

    Reliability study of HV substations equipped with the fault current limiter

    , Article IEEE Transactions on Power Delivery ; Vol. 27, issue. 2 , 2012 , p. 610-617 ; ISSN: 8858977 Fotuhi-Firuzabad, M ; Aminifar, F ; Rahmati, I ; Sharif University of Technology
    Abstract
    Of particular interest to restrict the short-circuit level of interconnected power systems is to exploit fault current limiter (FCL) technologies. FCLs let the system planners devise new reliable and rather economical substation configurations and provide the possibility of proposing a promising cost-effective and prompt solution to the fault current over duty problem in the existing substations. This paper attempts to assess reliability of substation architectures accommodating the FCL operation and, besides, numerically investigates the FCL's impacts on the substation reliability indices. In order to clarify the proposed approach, two case studies with and without FCL are analyzed and... 

    Reliability study of HV substations equipped with the fault current limiter

    , Article IEEE Transactions on Power Delivery ; Volume 27, Issue 2 , 2012 , Pages 610-617 ; 08858977 (ISSN) Fotuhi Firuzabad, M ; Aminifar, F ; Rahmati, I ; Sharif University of Technology
    2012
    Abstract
    Of particular interest to restrict the short-circuit level of interconnected power systems is to exploit fault current limiter (FCL) technologies. FCLs let the system planners devise new reliable and rather economical substation configurations and provide the possibility of proposing a promising cost-effective and prompt solution to the fault current over duty problem in the existing substations. This paper attempts to assess reliability of substation architectures accommodating the FCL operation and, besides, numerically investigates the FCL's impacts on the substation reliability indices. In order to clarify the proposed approach, two case studies with and without FCL are analyzed and... 

    Reliability evaluation of power grids considering integrity attacks against substation protective IEDs

    , Article IEEE Transactions on Industrial Informatics ; Volume 16, Issue 2 , 2020 , Pages 1035-1044 Bahrami, M ; Fotuhi Firuzabad, M ; Farzin, H ; Sharif University of Technology
    IEEE Computer Society  2020
    Abstract
    Secure operation of protective intelligent electronic devices (IEDs) has been recognized as a crucial issue for power grids. By gaining access to substation IEDs, intruders can severely disrupt the operation of protection systems. This paper develops an analytical reliability assessment framework for quantifying the impacts of the hypothesized integrity attacks against protection systems. Petri net models are used to simulate possible intrusion scenarios into substation networks. The cyber network model is constructed from firewall, intrusion prevention system (IPS), and password models, which are three types of defense mechanisms for protecting substation networks. In this paper, two main... 

    Reliability evaluation of non-reparable three-state systems using Markov model and its comparison with the UGF and the recursive methods

    , Article Reliability Engineering and System Safety ; Vol. 129 , September , 2014 , pp. 29-35 ; ISSN: 0951-8320 Pourkarim Guilani, P ; Sharifi, M ; Niaki, S. T. A ; Zaretalab, A ; Sharif University of Technology
    Abstract
    In multi-state systems (MSS) reliability problems, it is assumed that the components of each subsystem have different performance rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed universal generation function (UGF) and the recursive algorithm to obtain reliability of systems consisting of a large number of components. This research deals with evaluating non-repairable three-state systems reliability and proposes a novel method based on a Markov process for which an appropriate state definition is provided. It is shown that solving the derived differential equations significantly reduces the computational time compared... 

    Reliability evaluation of HV substations in the presence of Fault Current Limiter

    , Article 2009 IEEE Bucharest PowerTech: Innovative Ideas Toward the Electrical Grid of the Future, 28 June 2009 through 2 July 2009 ; 28 June-2 July , 2009 ; 9781424422357 (ISBN) Rahmati, I ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Abstract
    Short circuit current is one of the major threats for power system stability. Power system should have the ability to detect and clear these faults within a specified time. The protection system can clear the faults only if the interruption capability of the circuit breakers is higher than the fault level. Expansion of the grid and installation of new power on the scale that is envisaged will require practical solutions to a number of technical challenges. One of the technical challenges is fault level management as system expansion often results in increased fault levels beyond the design limits of the existing switchgears. Replacing the old equipments particularly circuit breakers with the... 

    Reliability evaluation of a small area in a composite power system using branch-cutting method and load uncertainty

    , Article Canadian Conference on Electrical and Computer Engineering 2005, Saskatoon, SK, 1 May 2005 through 4 May 2005 ; Volume 2005 , 2005 , Pages 2220-2223 ; 08407789 (ISSN) Gharagozloo, H ; Haghifam, M. R ; Fotuhi Firuzabad, M ; Farrokhzad, D ; Sharif University of Technology
    2005
    Abstract
    In many applications, the requirements of static data and large computation times are still major concerns. This paper presents a practical equivalent model of a small area in a large scale system which needs less statistical data of system equipments with acceptable level of accuracy. The proposed technique is designated as the Branch-Cutting Method in which tie lines between the area of interest (AI) and the other parts of the network are cut and the network behavior is modeled with some load and generating units in marginal load points. The load at marginal load points is represented as a multi state load model with the associated state probability. Load uncertainty is modeled using the... 

    Reliability evaluation of an HVDC transmission system tapped by a VSC station

    , Article IEEE Transactions on Power Delivery ; Vol. 25, issue. 3 , 2010 , p. 1962-1970 ; ISSN: 8858977 Zadkhast, S ; Fotuhi-Firuzabad, M ; Aminifar, F ; Billinton, R ; Faried, S. O ; Edris, A. -A ; Sharif University of Technology
    Abstract
    Reliability evaluation of multiterminal HVDC systems has received very little attention in the past. This paper presents reliability modeling and analysis of an HVDC transmission system incorporating a voltage-sourced converter (VSC) tapping station. The use of VSC tapping stations enables the supply of power along the route to areas with comparatively little consumption. In this paper, a comprehensive detailed reliability model is developed and then converted to a manageable and computationally efficient model. Using this equivalent reliability model, various reliability indices are calculated at the load point of the system and the impacts of the VSC tapping station on these indices are... 

    Reliability evaluation of an HVDC transmission system tapped by a VSC station

    , Article IEEE Transactions on Power Delivery ; Volume 25, Issue 3 , April , 2010 , Pages 1962-1970 ; 08858977 (ISSN) Zadkhast, S ; Fotuhi Firuzabad, M ; Aminifar, F ; Billinton, R ; Faried, S. O ; Edris, A. A ; Sharif University of Technology
    2010
    Abstract
    Reliability evaluation of multiterminal HVDC systems has received very little attention in the past. This paper presents reliability modeling and analysis of an HVDC transmission system incorporating a voltage-sourced converter (VSC) tapping station. The use of VSC tapping stations enables the supply of power along the route to areas with comparatively little consumption. In this paper, a comprehensive detailed reliability model is developed and then converted to a manageable and computationally efficient model. Using this equivalent reliability model, various reliability indices are calculated at the load point of the system and the impacts of the VSC tapping station on these indices are...