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Reliability-based selection of wind turbines for large-scale wind farms
, Article World Academy of Science, Engineering and Technology ; Volume 37 , 2009 , Pages 734-740 ; 2010376X (ISSN) ; Salehi Dobakhshari, A ; Sharif University of Technology
2009
Abstract
This paper presents a reliability-based approach to select appropriate wind turbine types for a wind farm considering site-specific wind speed patterns. An actual wind farm in the northern region of Iran with the wind speed registration of one year is studied in this paper. An analytic approach based on total probability theorem is utilized in this paper to model the probabilistic behavior of both turbines' availability and wind speed. Well-known probabilistic reliability indices such as loss of load expectation (LOLE), expected energy not supplied (EENS) and incremental peak load carrying capability (IPLCC) for wind power integration in the Roy Billinton Test System (RBTS) are examined. The...
Optimal DG placement in distribution systems using cost/worth analysis
, Article World Academy of Science, Engineering and Technology ; Volume 37 , 2009 , Pages 746-753 ; 2010376X (ISSN) ; Abbaspour, A ; Rajabi Ghahnavieh, A ; Fotuhi Firuzabad, M ; Sharif University of Technology
2009
Abstract
DG application has received increasing attention during recent years. The impact of DG on various aspects of distribution system operation, such as reliability and energy loss, depend highly on DG location in distribution feeder. Optimal DG placement is an important subject which has not been fully discussed yet. This paper presents an optimization method to determine optimal DG placement, based on a cost/worth analysis approach. This method considers technical and economical factors such as energy loss, load point reliability indices and DG costs, and particularly, portability of DG. The proposed method is applied to a test system and the impacts of different parameters such as load growth...
A low-cost on-line monitoring mechanism for the flexray communication protocol
, Article Proceedings - 2009 4th Latin-American Symposium on Dependable Computing, LADC 2009, 1 September 2009 through 4 September 2009, Joao Pessoa ; 2009 , Pages 111-118 ; 9780769537603 (ISBN) ; Miremadi, G ; Sharif University of Technology
2009
Abstract
Nowadays, communication protocols are used in safety-critical automotive applications. In these applications, fault tolerance is a main requirement and the existence of single points of failure is a serious threat to system failures. Among the communication protocols, FlexRay is expected to become the communication backbone for future automotive systems. In this paper, we identify single points of failure in the FlexRay protocol by injecting a total of 135,600 single-bit transient faults into all accessible registers of the FlexRay communication controller. The results showed that about 1.2% of all injected faults caused the controller to freeze immediately. Based on these results and...
An efficient mixed-integer linear formulation for long-term overhead lines maintenance scheduling in power distribution systems
, Article IEEE Transactions on Power Delivery ; Volume 24, Issue 4 , 2009 , Pages 2043-2053 ; 08858977 (ISSN) ; Fotuhi Firuzabad, M ; Abbasi, E ; Sharif University of Technology
2009
Abstract
This paper presents an efficient mixed-integer linear formulation for long term maintenance schedule of overhead lines. The proposed formulation is based on risk management approach and utilizes the model of decoupled risk factors. The proposed methodology yields a significant computational saving comparing to the previously reported dynamic programming. Risk management approach enables the asset managers to consider the actual condition of electrical equipment and expected consequence of their failures. Furthermore, the decoupled risk strategy in conjunction with the mixed-integer linear programming formulation establishes a precise description of time-dependent deterioration failure rate...
Impacts of automatic control systems of loop restoration scheme on the distribution system reliability
, Article IET Generation, Transmission and Distribution ; Volume 3, Issue 10 , 2009 , Pages 891-902 ; 17518687 (ISSN) ; Fotuhi Firuzabad, M ; Sanaye Pasand, M ; Lehtonen, M ; Sharif University of Technology
2009
Abstract
Loop restoration scheme (LRS) is a special feeder automation (FA) scheme, which is used by utilities to improve distribution system reliability. The LRS is controlled and managed by its automatic control system (ACS). The impacts on distribution system reliability indices of implementing LRS mainly depend on the type of its ACS. Two common types of ACS of LRS are presented and used in this study. Successful operation of ACS is dependent on the protection and automatic control functions of switching devices of LRS. Different failure modes of these switching devices can therefore affect the procedure of ACS in fault detecting, isolating and service restoration. The impacts of failure of...
Electricity generation scheduling with large-scale wind farms using particle swarm optimization
, Article Electric Power Systems Research ; Volume 79, Issue 5 , 2009 , Pages 826-836 ; 03787796 (ISSN) ; Vakilian, M ; Sharif University of Technology
2009
Abstract
Large-scale integration of wind power in the electricity system presents some planning and operational difficulties, which are mainly due to the intermittent and difficult nature of wind prediction process. Therefore it is considered as an unreliable energy source. This paper presents a new approach for solving the generation scheduling (GS) problem. It will consider the reserve requirement, load balance and wind power availability constraints. The particle swarm optimization (PSO) method is suggested to deal with the equality and inequality constraints in the GS problem. The proposed PSO is applied to a 12-unit test system (including 10 conventional thermal generating units and 2 wind...
A simple three-phase model for distributed static series compensator (DSSC) in Newton power flow
, Article 2009 Asia-Pacific Power and Energy Engineering Conference, APPEEC 2009, Wuhan, 27 March 2009 through 31 March 2009 ; 2009 ; 21574839 (ISSN); 9781424424870 (ISBN) ; Mokhtari, H ; Wuhan University; IEEE Power and Energy Society; Chinese Society for Electrical Engineering; Scientific Research Publishing ; Sharif University of Technology
2009
Abstract
Load flow problems have always been an important issue in power system analysis and require proper modeling of system components. In this regard Flexible AC Transmission System (FACTS) controllers are modern devices that their modeling specially the series type is a challenging topic. This paper describes a three-phase model for Distributed Static Series Compensator (DSSC) based on extending the Static Synchronous Series Compensator (SSSC) model in Newton power flow. To extend the SSSC model the following two differences must be considered; three completely independent phases and the existence of several modules in a DSSC system. Simulation results on the IEEE 30-bus system and a five bus...
Evaluation of UPFC impacts on power system reliability
, Article Transmission and Distribution Exposition Conference: 2008 IEEE PES Powering Toward the Future, PIMS 2008, Chicago, IL, 21 April 2008 through 24 April 2008 ; May , 2008 ; 9781424419036 (ISBN) ; Fotuhi Firuzabad, M ; Feuillet, R ; Sharif University of Technology
2008
Abstract
This paper evaluates the reliability impact of UPFC application in power system. The paper proposes a new reliability model for the UPFC which is capable of considering different operating states of UPFC. The model is then applied to a test system to study the reliability impacts of UPFC. The impacts of operating points of different states of the model on the system reliability are analyzed. The role of model parameters in reliability impacts of UPFC is analyzed through the sensitivity analysis. A comparative study is finally conducted to illustrate the applicability of the proposed model compare to that of existing UPFC reliability models. The abilities and deficiencies of the proposed...
Optimal power flow solution by a modified particle swarm optimization algorithm
, Article Proceedings of the Universities Power Engineering Conference, 1 September 2008 through 4 September 2008, Padova ; 2008 ; 9788889884096 (ISBN) ; Hosseini, H ; Hajian, M ; Sharif University of Technology
2008
Abstract
This paper presents a modified particle swarm optimization (MPSO) algorithm for solving the optimal power flow (OPF) problems. The main distinction of this approach is in using particle's worth experience in stead of the best previous experience. The proposed approach is evaluated on the IEEE 30-bus test system which minimizes the total fuel cost considering operational constraints such as power flow equations, transmission flow limits, bus voltages and reactive power of generators. The results obtained using the proposed approach are compared with results of other optimization methods
Fuzzy generating units dispatch considering the load interruption cost
, Article 42nd International Conference on Large High Voltage Electric Systems 2008, CIGRE 2008, Paris, 24 August 2008 through 29 August 2008 ; 2008 ; Ahmadi Khatir, A ; Jamshidi, A ; Sharif University of Technology
2008
Abstract
In the new environment of power system, generating units dispatch problem plays an important role inasmuch as it is used to clear power market transactions. That is, market operator solves an optimization problem in order to find the energy and capacity reserve quota of each generating units participating in the power market. There are different techniques for solving this problem which differ in many aspects, including the objective function, optimization algorithm, and feasibility, so using an efficient technique is vital. In the real competitive electricity market, the components of generating units dispatch problem are faced with the uncertainties; therefore, due to the presence of...
A heuristic trade off model for integration of distributed generations in deregulated power systems considering technical, economical and environmental issues
, Article 2008 IEEE 2nd International Power and Energy Conference, PECon 2008, Johor Baharu, 1 December 2008 through 3 December 2008 ; 2008 , Pages 1275-1279 ; 9781424424054 (ISBN) ; Nasiri, R ; Bagheri, M ; Tehrani, A. A ; Sharif University of Technology
2008
Abstract
With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within...
A performance-based markov modeling for reliability evaluation of competitive electricity markets
, Article Proceedings of the 10th IASTED International Conference on Power and Energy Systems, PES 2008, 16 April 2008 through 18 April 2008, Baltimore, MD ; 2008 , Pages 215-220 ; 9780889867383 (ISBN) ; Ranjbar, A. M ; Fotuhi Firuzabad, M ; Sharif University of Technology
2008
Abstract
In the new deregulated environment of electric power utility industry, new system reliability criteria and analytical tools are required. This paper proposes an analytical probabilistic model for reliability evaluation of competitive electricity markets. The market reliability is evaluated by using Markov state space diagram. Since the market is a continuously operated system, the concept of absorbing states is applied to it in order to evaluate the reliability. The market states are identified by using market performance indices and the transition rates are calculated by using historical data. To illustrate interesting feature of the proposed methodology, a case study is carried out over a...
Observability and estimation of transformer tap setting with minimal PMU placement
, Article IEEE Power and Energy Society 2008 General Meeting: Conversion and Delivery of Electrical Energy in the 21st Century, PES, Pittsburgh, PA, 20 July 2008 through 24 July 2008 ; 2008 ; 9781424419067 (ISBN) ; Hosseini, S. H ; Sharif University of Technology
2008
Abstract
One of the most important applications of phasor measurement units (PMUs) is power system state estimation. Some models have been proposed for including phasor measurements in the state estimation. But, all of these models have treated transformer tap settings (voltage transformer turns ratio and phase-shift transformer angle) as fixed parameters of the network. The accuracy of state estimation may decrease when a tap changes or the true value is unknown. In this paper, each transformer tap setting is added as a new state variable to the states vector, converting the linear PMU based state estimation to a nonlinear one. Also, the network observability is analyzed including the observability...
Optimum simultaneous clearing of energy and spinning reserve markets using cost/benefit analysis
, Article IEEE Power and Energy Society 2008 General Meeting: Conversion and Delivery of Electrical Energy in the 21st Century, PES, Pittsburgh, PA, 20 July 2008 through 24 July 2008 ; 2008 ; 9781424419067 (ISBN) ; Fotuhi Firuzabad, M ; Zareipour, H ; Sharif University of Technology
2008
Abstract
Considering the high level of interactions between energy and reserve markets, simultaneous clearing of these markets has been shown to provide more efficient solutions, than a sequential market clearing process. In addition, determining reserve requirements based on probabilistic approaches results in more economical efficiency, while maintaining an acceptable level of reliability, compared to deterministic approaches. This paper proposes a new method for clearing energy and spinning reserve markets simultaneously, while at the same time, spinning reserve requirements are determined based on a cost/benefit analysis as a probabilistic-based approach. This cost/benefit analysis considers both...
Limiting fault currents in wind power plants using superconductive shielded core reactors
, Article IEEE Power and Energy Society 2008 General Meeting: Conversion and Delivery of Electrical Energy in the 21st Century, PES, Pittsburgh, PA, 20 July 2008 through 24 July 2008 ; 2008 ; 9781424419067 (ISBN) ; Salehfar, H ; Varahram, H ; Sharif University of Technology
2008
Abstract
In this paper we investigate the effects of superconducting shielded core reactor (SSCR) on the operation of induction generators. Large number of induction generators used in wind power plants generally increase the short circuit current level of the system. The reason is that they provide parallel reduced-impedance paths for the fault currents. Taking advantage of SSCR in wind power plants allows for using these generating units in large numbers with no concerns about the system fault current increments. The study is performed on a test system using the conventional model of an induction generator and a new effective model for SSCR based on its shielding behavior. Mathematical equations...
Optimal allocation of spinning reserve in a restructured power system using particle swarm optimization
, Article IEEE Canadian Conference on Electrical and Computer Engineering, CCECE 2008, Niagara Falls, ON, 4 May 2008 through 7 May 2008 ; 2008 , Pages 535-540 ; 08407789 (ISSN) ; 9781424416431 (ISBN) ; Fotubi Firuzabad, M ; Hajian, M ; Sharif University of Technology
2008
Abstract
A reasonable amount of spinning reserve is essential to satisfy system security constraints when the power system encounters a contingency. Most ofthe methods previously developed for spinning reserve assessment ignore the probabilistic aspects of system components. This paper presents the design of a market for energy and spinning reserve services. This dispatching method has been developed to minimize the cost associated with theses services while maintaining the system security. Particle swarm optimization (PSO) is used for determining the global optimal solution for this dispatch problem. The effectiveness of the proposed approach is examined by application to the IEEE Reliability Test...
Optimal PMU placement for power system observability considering secondary voltage control
, Article IEEE Canadian Conference on Electrical and Computer Engineering, CCECE 2008, Niagara Falls, ON, 4 May 2008 through 7 May 2008 ; 2008 , Pages 365-368 ; 08407789 (ISSN) ; 9781424416431 (ISBN) ; Hosseini, S. H ; Sharif University of Technology
2008
Abstract
This paper presents an optimal phasor measurement units (PMUs) placement algorithm for the purpose of power system observability and also increasing the performance of secondary voltage control scheme. The optimal placement problem (OPP) is formulated such that to minimize the number of PMU installations subject to full network observability and monitoring pilot buses of the system to improve secondary voltage control performance. The branch and bound optimization method is adopted to solve the OPP problem which is suitable for problems with integer and boolean variables. Topology-based algorithm is used for observability analysis. Constraint functions considering adjacent zero-injection...
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) ; Sedighizadeh, M ; Bayat, M. R ; Khodayar, M. E ; Sharif University of Technology
2007
Abstract
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...
Optimal placement of phasor measurement units: Particle swarm optimization approach
, Article 2007 International Conference on Intelligent Systems Applications to Power Systems, ISAP ; 2007 ; 9860130868 (ISBN); 9789860130867 (ISBN) ; Ranjbar, A. M ; Amraee, T ; Shirani, A. R ; Sharif University of Technology
2007
Abstract
This paper is concerned about the optimal placement of phasor measurement units (PMUs) so as to make a system completely observable. Observability assessment is done by the aid of the topological observability rules. Moreover a new rule is added which can decrease the number of required PMUs for complete system observability. A modified binary particle swarm is used as an optimization tool for obtaining the minimal number of PMUs and corresponding configuration. In order to improve the speed of convergence, an initial PMU placement is provided by graph-theoretic procedure. The simulation results of proposed approach are presented for several IEEE test systems
Optimal reactive power dispatch in a joint active / reactive market model
, Article 2006 IEEE PES Transmission and Distribution Conference and Exposition: Latin America, TDC'06, Caracas, 15 August 2006 through 18 August 2006 ; 2006 ; 1424402883 (ISBN); 9781424402885 (ISBN) ; Amraee, T ; Ranjbar, A. M ; Mirjafari, M ; Shirani, A. R ; Sharif University of Technology
2006
Abstract
The participants in auction-based electricity markets need to take part in a competition way, which operates, based on the concept of supply and demand theory to buy or sell the electricity. However, to have a feasible market solution, reactive power services are necessary to support the transmission of power from generation to end-users. This paper presents a methodology for optimal reactive power procurement, consistent with the auction-based electricity market mechanism. The proposed reactive power market is run in subsequence of the primary electricity market, allowing active power modification in light of available transmission capacity and reactive power resources. The IEEE 30-bus test...