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Transmission Expansion Planning Considering Uncertainty in Generation and N-1 Criterion
, M.Sc. Thesis Sharif University of Technology ; Ehsan , Mehdi (Supervisor)
Abstract
In order to reduce investment and operation costs of the power systems, transmission expansion planning is inevitable. In fact, transmission expansion planning is to determine when, where and how many lines need to be added to power system with a minimum of investment and operating costs. In this thesis, transmission expansion planning has been performed at uncertainty in generation and N-1 criterion condition where uncertainty in generation means uncertainty in the moment of adding power plant to power system. In previous studies, transmission expansion planning was performed with DC-load flow in which, the power loss and voltage profiles were ignored due to the approximation in the...
Design and Implementation of Three Phase Regenerative Electronic AC Load
, M.Sc. Thesis Sharif University of Technology ; Zolghadri, Mohammd Reza (Supervisor)
Abstract
Three-phase electronic loads are used to test the performance of various electrical devices such as power supplies, generators, and transformers. Conventional electronic loads are composed of passive components that consume the energy, so have low power density and efficiency and to manage the produced heat, massive cooling systems are required. Nowadays, to increase efficiency and power density, three-phase regenerative electronic AC loads have been developed. To return energy to the grid and control the input power factor, the structure of these loads is based on back-to-back converters. In this project, a 35 kVA three-phase regenerative electronic AC load is designed. To control the power...
Model Predictive Controller Design for Regenerative Electronic AC Load
, M.Sc. Thesis Sharif University of Technology ; Zolghadri, MohammadReza (Supervisor)
Abstract
Generally, virtual loads is used to test all AC power and energy meters and are usually passive. To prevent possible damage of this heat and to control the temperature, cooling blowers are used which increases the volume and weight. So, recycling the power delivered from the grid causes a small amount of power to be converted to heat in proportion to the load efficiency. The purpose of this study is design, predictive controller model for programmable electronic regenerative AC load. The structure used is a back-to-back converter consisting of an AC-DC converter and a DC-AC converter, which according to existence of capacitance between these two structures, two converters can be controlled...
Intelligent topology-oriented load shedding scheme in power systems
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 652-656 ; 9781728115085 (ISBN) ; Ranjbar, A ; Faghihi, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Load shedding is a prevalent emergency control designed to prevent system blackouts. The higher complexity and lower predictability of modern power systems makes it difficult to rely on conventional load shedding schemes which shed loads in pre-defined steps without sufficient consideration of the actual system characteristics and the disturbance situations. In case of large disturbances, the power system stability can be improved by optimal load shedding in more effective load buses. Proposed scheme utilizes improved Power Flow Tracing method to determine the amount and location of load drops considering power system constraints. Numerical simulations conducted on IEEE 39 bus standard test...
Intelligent topology-oriented LS scheme in power systems integrated with high wind power penetration
, Article IET Generation, Transmission and Distribution ; Volume 14, Issue 9 , 2020 , Pages 1684-1693 ; Ranjbar, A ; Faghihi, F ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
Load shedding (LS) is one of the most important protection schemes to prevent system blackout. In the case of largedisturbances, optimal LS in appropriate buses can effectively maintain the system stability. The higher complexity and lowerpredictability of modern power systems with high wind power penetration make it difficult to rely on conventional LS schemes,which shed a fixed, predetermined amount of load regardless of disturbance location. This study presents an intelligent LSscheme based on synchrophasor measurements that are adapted to both disturbance size and power system inertia. Theproposed scheme utilises improved power flow tracing method to determine the amount and location of...
Decentralized active power management in multi-agent distribution systems considering congestion issue
, Article IEEE Transactions on Smart Grid ; Volume 13, Issue 5 , 2022 , Pages 3582-3593 ; 19493053 (ISSN) ; Fattaheian Dehkordi, S ; Fotuhi Firuzabad, M ; Lehtonen, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Recently, due to the restructuring of power systems and the high penetration level of local renewables, distribution systems have encountered with the complexity of power management. Therefore, the modern systems would be operated in a multi-agent structure which facilitates the power management as well as privacy protections of independent entities. In this structure, the distribution system is assumed to compose of several agents who independently schedule their local resources in order to maximize their own profits. Consequently, this paper provides an efficient peer-to-peer (P2P) active power management framework in a multi-agent distribution system while considering network constraints...
The effect of fuel cell operational conditions on the water content distribution in the polymer electrolyte membrane
, Article Renewable Energy ; Volume 36, Issue 12 , December , 2011 , Pages 3319-3331 ; 09601481 (ISSN) ; Roshandel, R ; Sharif University of Technology
2011
Abstract
Models play an important role in fuel cell design and development. One of the critical problems to overcome in the proton exchange membrane (PEM) fuel cells is the water management. In this work a steady state, two-dimensional, isothermal model in a single PEM fuel cell using individual computational fluid dynamics code was presented. Special attention was devoted to the water transport through the membrane which is assumed to be combined effect of diffusion, electro-osmotic drag and convection. The effect of current density variation distribution on the water content (λ) in membrane/electrode assembly (MEA) was determined. In this work the membrane heat conductivity is considered as a...
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) ; Ehsan, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
Turkiye Klinikleri
2019
Abstract
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...
Sensitivity-based generators redispatch to improve electromechanical mode damping considering transmission lines resistance
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 491-496 ; 9781728115085 (ISBN) ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
This paper proposes a novel formula to calculate sensitivities of electromechanical modes to generators active power changes. Quadratic eigenvalue problem is applied to construct the framework of the proposed formula. Sensitivity factors are calculated using power system model parameters and power flow variables, which can be either obtained via state estimation or measured directly by phasor measurement units. The 39-bus New England power system is used to verify performance of the proposed method
An analytic methodology to determine generators redispatch for proactive damping of critical electromechanical oscillations
, Article International Journal of Electrical Power and Energy Systems ; Volume 123 , 2020 ; Parniani, M ; Aminifar, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
This paper presents a model-based method for applying online proactive generators redispatch to improve damping of the critical electromechanical oscillations of power system. The proposed method comprises two stages: 1) monitoring modal characteristics of oscillatory modes in ambient condition, and 2) applying generators redispatch based on sensitivities of the critical mode to the generators active power changes using a new analytic method. An online identification method such as error feedback lattice recursive least square adaptive filter is applied for online estimation of the oscillatory modes. Then, whenever the damping ratio of an identified mode is less than a preset threshold, its...
Electrical power system resilience assessment: a comprehensive approach
, Article IEEE Systems Journal ; Volume 14, Issue 2 , 2020 , Pages 2643-2652 ; Doroudi, A ; Fotuhi Firuzabad, M ; Bashiri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Extreme weather events such as earthquake and hurricane have disastrous consequences on power systems. Due to the inherent nature of these events, as high-impact low-probability (HILP) events, selection of an appropriate method that can provide the effects of weather conditions on the power system behavior still remains a significant challenge. Resilience is a new concept that focuses on mitigating the destructive effects of such disastrous events on power systems. This article provides a fundamental framework for quantifying and modeling of power systems resilience, with focus on high wind incidence. The algorithm composes of four steps. In the first step, the prerequisites of the analysis...
Utilization of in-pipe hydropower renewable energy technology and energy storage systems in mountainous distribution networks
, Article Renewable Energy ; Volume 172 , 2021 , Pages 789-801 ; 09601481 (ISSN) ; Mazaheri, H ; Ranjbar, H ; Moeini Aghtaie, M ; Lehtonen, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Million miles of gravity-fed drinking water and sewage pipelines around the world, especially in rural and urban areas in mountain ranges, have introduced a new renewable energy sources (RES), i.e., in-pipe hydropower systems (IHS). Output power of this technology, similar to other types of RES, suffers from intermittency, while it is still more predictable in comparison to other technologies of RESs. Besides, energy storage systems (ESS) are introduced as a pivotal technology for dealing with the intermittent and non-dispatchable characteristics of IHS through spatio-temporal arbitrage. This paper aims to develop a stochastic mixed-integer linear programming (MILP) formulation that...
An optimal and decentralized transactive energy system for electrical grids with high penetration of renewable energy sources
, Article International Journal of Electrical Power and Energy Systems ; Volume 113 , 2019 , Pages 850-860 ; 01420615 (ISSN) ; Amirzadeh Goghari, S ; Nasiri Gheidari, Z ; Ranjbar, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this paper, a hierarchical frequency regulation system is presented for real-time operation of the electrical grids. It includes a decentralized transactive energy system for clearing transactions of producers/consumers in real-time. The proposed system is implemented in a distributed fashion with small data communication requirement. It is proved that the proposed transactive energy system converges to the optimal power flow (OPF). An iterative method for optimizing control parameters of the proposed hierarchical frequency regulation system is also given. The proposed method is developed for high penetration of renewable energy sources (RESs) as the sizes, locations, and uncertainties of...
Optimal zonal fast-charging station placement considering urban traffic circulation
, Article IEEE Transactions on Vehicular Technology ; Volume 66, Issue 1 , 2017 , Pages 45-56 ; 00189545 (ISSN) ; Sadeghi Barzani, P ; Sharif University of Technology
Abstract
Fast-charging stations are connected to the electric grid and can fully charge an electric vehicle (EV) in less than half an hour. The capacity and location of the charging stations bring the costs to the electric grid operator, as well as to the station owner and EV user. A zonal approach has been proposed in this paper to determine the optimal place and capacity of fast-charging stations. Station development cost and the expected costs incurred by the EV user and the grid operator due to EV charging have also been included in the proposed approach. The geographic characteristics associated with the electric substations, urban roads, and city zones have also been considered in the proposed...
Optimal reactive power dispatch using the concept of dynamic VAR source value
, Article 2009 IEEE Power and Energy Society General Meeting, PES '09, 26 July 2009 through 30 July 2009, Calgary, AB ; 2009 ; 9781424442416 (ISBN) ; Parniani, M ; Sharif University of Technology
Abstract
Voltage stability is the ability of a power system to maintain acceptable voltages at all buses in the system under normal conditions and after being subjected to a disturbance. This paper employs the management of reactive power generation to improve the voltage stability margin (VSM), in the framework of optimal reactive power dispatch (ORD) problem. Scheduling of VAR sources is performed using the concept of relative value of VAR sources. The proposed methodology has been tested on the IEEE 14-bus test system. Simulation results show that after the optimal reactive power scheduling, VSM of the systems is increased considerably. In addition, it is observed that reactive power reserve is...
Optimal power flow problem considering multiple-fuel options and disjoint operating zones: A solver-friendly MINLP model
, Article International Journal of Electrical Power and Energy Systems ; Volume 113 , 2019 , Pages 45-55 ; 01420615 (ISSN) ; Lehtonen, M ; Fotuhi Firuzabad, M ; Marzband, M ; Mantovani, J. R. S ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
This paper proposes a solver-friendly model for disjoint, non-smooth, and nonconvex optimal power flow (OPF) problems. The conventional OPF problem is considered as a nonconvex and highly nonlinear problem for which finding a high-quality solution is a big challenge. However, considering practical logic-based constraints, namely multiple-fuel options (MFOs) and prohibited operating zones (POZs), jointly with the non-smooth terms such as valve point effect (VPE) results in even more difficulties in finding a near-optimal solution. In complex problems, the nonlinearity itself is not a big issue in finding the optimal solution, but the nonconvexity does matter and considering MFO, POZ, and VPE...
A dynamic programming-based heuristic approach for optimal transmission switching problem with N-1 reliability criterion
, Article 2016 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2016 - Proceedings, 16 October 2016 through 20 October 2016 ; 2016 ; 9781509019700 (ISBN) ; Jooshaki, M ; Hosseini, S. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Minimization of operating costs is one of the most important objectives of power system operators. To achieve this goal, several optimization problems such as unit commitment and optimal power flow have been introduced. Historically, in these problems, the transmission network has been considered as a static system, i.e., the ability of transmission lines switching is not modeled. On the other hand, it has been shown that transmission line switching can significantly reduce operating costs by the means of topology modification. However, considering this capability, a large number of binary variables are introduced in the objective function, and as a consequence, the computation time will be...
Smart power management of DC microgrids in future milligrids
, Article 2016 18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe, 5 September 2016 through 9 September 2016 ; 2016 ; 9789075815245 (ISBN) ; Mokhtari, H ; Davari, P ; Loh, P. C ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper a novel droop approach for power management in low voltage dc MicroGrids (MGs) based on a master-slave concept is presented. A virtual frequency is injected by a master unit, which is proportional to its output power. Other slave units determine their output power according to the corresponding frequency based droop characteristics. Unlike the dc voltage-droop methods, the proposed virtual frequency-droop approach can be smartly applied for proportional power management among the energy units and loads as well as adding zero net energy capability to the MG. Both power flow and energy flow can be performed without utilizing an extra communication system. Simulation results...
Autonomous operation of a hybrid AC/DC microgrid with multiple interlinking converters
, Article IEEE Transactions on Smart Grid ; Volume 9, Issue 6 , 2018 , Pages 6480-6488 ; 19493053 (ISSN) ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Applying conventional dc-voltage-based droop approaches for hybrid ac/dc microgrids interconnected by a single interlinking converter (IC) can properly manage the power flow among ac and dc subgrids. However, due to the effect of line resistances, these approaches may create a circulating power as well as overstressing the ICs in the case of employing multiple ICs for interconnecting the ac and dc subgrids. This paper proposes an autonomous power sharing approach for hybrid microgrids interconnected through multiple ICs by introducing a superimposed frequency in the dc subgrid. Hence, a suitable droop approach is presented to manage the power among the dc and ac sources as well as ICs. The...
Probabilistic assessment and sensitivity analysis of marginal price of different services in power markets
, Article IEEE Systems Journal ; Volume 7, Issue 4 , May , 2013 , Pages 873-880 ; 19328184 (ISSN) ; Afkousi-Paqaleh, M ; Hosseini, S. H ; Sharif University of Technology
2013
Abstract
Different sources of uncertainty in power systems, i.e., the uncertainties associated with bus loading and component availability is reflected in uncertainties in different system variables through system physical and economical relationships. A stochastic power flow algorithm can be used to model the stochastic nature of power systems. The algorithm introduced in this paper calculates the probability density function (pdf) of marginal prices of different market services. These pdfs provide the market participant with some valuable information to reduce the risk of their decisions and actions. The algorithm linearizes the optimal power flow formulation and uses the Gram-Charlier method to...