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distributed-generations
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Developing an Efficient Approach for Improving Operational Resilience of Power Distribution Network in Facing with Earthquake
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
The design and operation of energy systems infrastructure is typically based on key reliability criteria such as system security and adequacy. Nowaday, with the rise of unexpected events and events such as floods, earthquakes, storms, and other natural phenomena can affect the performance of energy infrastructure. Given the low probability of these events, reliability studies and relevant criteria cannot guarantee that an energy infrastructure can respond well to these events. Investigating the ability of energy infrastructures to deal with these phenomena is divided into resilience studies. To overcome these challenges, this thesis has attempted to detail some of these natural events....
The design and operation of energy systems infrastructure is typically based on key reliability criteria such as system security and adequacy. Nowaday, with the rise of unexpected events and events such as floods, earthquakes, storms, and other natural phenomena can affect the performance of energy infrastructure. Given the low probability of these events, reliability studies and relevant criteria cannot guarantee that an energy infrastructure can respond well to these events. Investigating the ability of energy infrastructures to deal with these phenomena is divided into resilience studies. To overcome these challenges, this thesis has attempted to detail some of these natural events....
Distribution System Planning Considering Demand Response Programs
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
Nowadays, moving toward new technologies and smart grids is a successful way to prevail over distribution system challenges. In the presence of smart grids, demand-side management (DSM) is capable to affect the expansion of network resources. An effective DSM tool is demand response (DR). In this thesis, distribution system planning (DSP) considering DR is presented and the effects of DR on DSP are investigated. This thesis proposes direct load control (DLC) DR which is an incentive-based program (IBP) where a utility offers financial incentives to the customers to control their consumption through installing smart meters and switches. The utility deploys the DR program to reduce network...
Design of a Coupled Thermoacoustic Refrigerator System based on Heat Absorption of Piston Engines of Power Plants
, M.Sc. Thesis Sharif University of Technology ; Mazaheri, Karim (Supervisor)
Abstract
Design and parametric study of a coupled thermoacoustic refrigerator system has been carried out based on thermoacoustic theories. The purpose of coupled thermoacoustic refrigerator design is to cool a container with small dimensions for use in cold storage above zero. The application of this refrigerator is where the waste heat of piston engines of distributed generation (DG) plants can be used as energy input. The design is based on the simplicity and low cost of the refrigerator. Therefore, the engine and refrigerator part of the coupled thermoacoustic refrigerator is enclosed in a resonator with a fixed diameter, which is closed on both sides of the resonator. Two standing-wave...
The Assessment of Cyber_Attacks on Electric Vehicles Charging by a Microgrid (Bus and Personal Vehicle)and Examining the Relevant Consequences in the Power Distribution Grid
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mehdi (Supervisor)
Abstract
Todays, thanks to the positive effects of electric vehicles, (against the vehicles which use patrol as their fuel), reduction of the Earth temperature and its climate change; the manufacturing, sale and use of electric vehicles experience a sharp increase. In addition to decreasing the air pollution, due to their abundant smart implications, they have been dramatically propagated. Massive use of these devices has raised the concern about the loss of the security which is indispensable part of the infrastructure. None of the past publications and works have taken the cyber-attack on the charging price rate and other data into account. In this thesis, charging methods of electric vehicles are...
A decentralized control method for a low-voltage dc microgrid
, Article IEEE Transactions on Energy Conversion ; Vol. 29, issue. 4 , Dec , 2014 , p. 793-801 ; 08858969 ; Ashourloo, M ; Mokhtari, H ; Sharif University of Technology
Abstract
DC microgrids (DC-MGs) are becoming popular as an effective means to integrate various renewable energy resources. Conventionally, the droop control is adopted as a decentralized control strategy for proper power sharing without using any communication link. However, the conventional droop control often deteriorates due to the effects of unequal line resistances. In this paper, a control strategy is proposed for a DC-MG to achieve perfect power sharing considering the effects of line resistances. The DC-MG under study consists of a photovoltaic system, two energy storage systems, a grid-connected converter system, and dc loads. The control strategy of the converters is addressed under...
An adaptive droop control method for low voltage DC microgrids
, Article PEDSTC 2014 - 5th Annual International Power Electronics, Drive Systems and Technologies Conference ; December , 2014 , p. 84-89 ; Ashourloo, M ; Mokhtari, H ; Sharif University of technology
Abstract
DC microgrids (MGs) are becoming popular as effective means to integrate different energy resources. Conventionally, the droop control is adopted as a decentralized control method for power sharing in DC MGs. However, current sharing accuracy or voltage regulation deteriorates due to the effects of line impedances. In this paper, a new adaptive control strategy is proposed for DC MGs. In low load conditions, the output currents of the DGs are far from their maximum acceptable limits. Therefore, current sharing accuracy is not important. As load increases, the output currents of the DGs approach their maximum acceptable limits. Therefore, at high load conditions, accurate current sharing is...
Voltage regulation through smart utilization of potential reactive power resources
, Article Proceedings - UKSim 5th European Modelling Symposium on Computer Modelling and Simulation, EMS 2011, 16 November 2011 through 18 November 2011, Madrid ; 2011 , Pages 293-298 ; 9780769546193 (ISBN) ; Abbaspour Tehrani Fard, A ; Dobakhshari, A. S ; Ranjbar, A. M ; Sharif University of Technology
Abstract
The introduction of demand response concept, in addition to increment of penetration of distributed generation (DG) based on renewable energies, make opportunities for the novel control schemes to be integrated in power system on a smart grid framework. Voltage control methods in power systems needs proper coordination among reactive power resources and conventional volt/var control equipments. In this work, potential reactive power resources are investigated and then, reactive power output of renewable DG units and controllable loads along with operation of conventional voltage controllers are optimized using a centralized control scheme. Considering the variability of demand and...
Design of low order dynamic pre-compensators using convex methods
, Article Proceedings of the American Control Conference, 29 June 2011 through 1 July 2011, San Francisco, CA ; 2011 , Pages 3680-3685 ; 07431619 (ISSN) ; 9781457700804 (ISBN) ; Nejati, A ; Nobakhti, A ; Karimi, H ; Sharif University of Technology
2011
Abstract
Pre-compensators are used in multivariable control systems to reduce (or eliminate) open loop system interactions. Classical methods for the design of pre-compensator are traditionally based on static designs. Static pre-compensators are preferred for their simplicity, but are highly unsystematic in the amounts of achievable diagonal dominance. In many applications, only the more powerful dynamic pre-compensators are able to deliver the desired amounts of decoupling. This paper proposes a new method for the design of dynamic pre-compensators which is based on a Quadratic Programming (QP) optimization. Using the proposed approach the total pre-compensator is found through several smaller...
Robust control of an autonomous four-wire electronically-coupled distributed generation unit
, Article IEEE Transactions on Power Delivery ; Volume 26, Issue 1 , September , 2011 , Pages 455-466 ; 08858977 (ISSN) ; Yazdani, A ; Iravani, R ; Sharif University of Technology
2011
Abstract
This paper proposes a control strategy for the autonomous (islanded) operation of a four-wire, electronically-coupled distributed generation (DG) unit which can feed a highly unbalanced load, e.g., due to the presence of single-phase loads. In the grid-connected mode, the power-electronic interface of the DG unit enables the exchange of real and reactive power with the distribution network, based on the conventional dq-frame current control strategy. The current control scheme is disabled subsequent to the detection of an islanding event, and the proposed controller is activated. The proposed control strategy utilizes: i) an internal oscillator to maintain the island frequency and ii) a...
A novel optimal distribution system planning framework implementing distributed generation in a deregulated electricity market
, Article Electric Power Systems Research ; Volume 80, Issue 7 , July , 2010 , Pages 828-837 ; 03787796 (ISSN) ; Poure, P ; Abbaspour Tehrani fard, A ; Saadate, S ; Sharif University of Technology
2010
Abstract
This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system...
Transmission congestion management using distributed generation considering load uncertainty
, Article Asia-Pacific Power and Energy Engineering Conference, APPEEC, 28 March 2010 through 31 March 2010 ; March , 2010 ; 21574839 (ISSN) ; 9781424448135 (ISBN) ; Noory, A. R ; Abbaspour T. F., A ; Rashidinejad, M ; Sharif University of Technology
2010
Abstract
This Paper presents a model for optimal locating and sizing of Distributed Generation (DG) for congestion management in deregulated electricity market. For reducing the solution space a priority list of candidate buses is formed and then optimal placement and sizing of DG in potential buses is discussed. In order to incorporate stochastic nature of power system in this study, Monte-Carlo method is used to simulate the effect of uncertainty of loads and system on the optimal location and size of the DGs in the network. The proposed method is applied to IEEE Reliability Test System (RTS). The impacts of load uncertainty on optimum DG size and location are studied
A novel isolated DC/DC converter for fuel cell powered load
, Article 2009 IEEE Electrical Power and Energy Conference, EPEC 2009, 22 October 2009 through 23 October 2009 ; 2009 ; 9781424445080 (ISBN) ; Hoseinnia, S ; Roshandel, R ; Sharif University of Technology
Abstract
Fuel Cell (FC) is one of the promising distributed generation resources which are based on renewable energies. Clean electricity generation, high efficiency and high energy density of the fuel cells make them attractive for lots of engineers. In this paper we discuss about the operational principles of fuel cell generally. Then, a circuit model of them will be introduced. Based on the model, we designed a novel DC/DC converter for supplying the fuel cell's load and simulated the design with using Matlab. The results say that its novel converter could conveniently supply the load and its needed power curve. ©2009 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...
Robust tuning of transient droop gains based on kharitonov's stability theorem in droopcontrolled microgrids
, Article IET Generation, Transmission and Distribution ; Volume 12, Issue 14 , 2018 , Pages 3495-3501 ; 17518687 (ISSN) ; Sadati, N ; Hamzeh, M ; Sharif University of Technology
Abstract
This study addresses the robust stability analysis for an islanded microgrid with droop-controlled inverter-based distributed generators (DGs). Owing to large load changes, microgrid structure reconfiguration, and higher-power demands, the low-frequency (LF) dominant modes of a microgrid stir toward unstable zone and make the system more oscillatory or even unstable. In this study, a robust two-degree-of-freedom (2DOF) decentralised droop controller, which is the combination of the conventional droop with a robust transient droop function, is utilised for each inverter-based DG unit. Unlike conventional tuning of 2DOF droop controllers, a new design procedure is proposed to robustly...
Distributed noise-resilient secondary voltage and frequency control for islanded microgrids
, Article IEEE Transactions on Smart Grid ; 2018 ; 19493053 (ISSN) ; Baghaee, H. R ; Sadati, N ; Guerrero, J. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper proposes a novel distributed noise-resilient secondary control for voltage and frequency restoration of islanded microgrid inverter-based distributed generations (DGs) with an additive type of noise. The existing distributed methods commonly are designed as secondary control system systems that operate on the assumption of ideal communication networks among DGs. However, the channels are prone to stochastic noise, whereas each DG obtains noisy measurements of the states of its neighbors via environmental noises. The existing distributed noise-resilient methods, ignore a complete model of the system. In contrast, this paper proposes consensus protocols that take into account both...
Enhancing power distribution system flexibility using electric vehicle charging management
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 782-786 ; 9781728115085 (ISBN) ; Jooshaki, M ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, a two-stage charging management framework is proposed to exploit the potential flexibility of Electric Vehicles (EVs). The aim is to reduce drastic variations in distribution system net load caused by integration of intermittent renewable distributed generation (DG) units. In the first stage, a home-based charging method is formulated in which the desired charging schedule of EVs is obtained by minimizing the cost of energy taking into account owners' preferences. The attained charging schedules are then announced to EVs Coordinator Agent (ECA) which, as the second stage, applies an LP optimization to reduce the cost of ramp provision. Moreover, an incentive scheme is...
Distribution system reconfiguration for loss reduction incorporating load and renewable generation uncertainties
, Article 2019 IEEE Texas Power and Energy Conference, TPEC 2019, 7 February 2019 through 8 February 2019 ; 2019 ; 9781538692844 (ISBN) ; Amini, M ; Modarresi, M. S ; Jafarishiadeh, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
A significant share of losses in power systems occurs in distribution network due to lower voltages and longer lines. On top of that, unbalanced operation causes additional losses in these networks. In recent years with the development of distributed generation connected to the distribution grid, the concern over frequency and intensity of unbalanced operation has risen. Reconfiguration of these distribution networks plays a significant role in power loss minimization and voltage quality enhancement. The uncertainty regarding grid-connected DG resources and net loads are among the critical factors that must be taken into account. To do so, in this paper a novel Fuzzy-based reconfiguration...
Reliability assessment of distribution system with distributed generation
, Article 2008 IEEE 2nd International Power and Energy Conference, PECon 2008, Johor Baharu, 1 December 2008 through 3 December 2008 ; January , 2008 , Pages 1551-1556 ; 9781424424054 (ISBN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
2008
Abstract
Reliability assessment is of primary importance in designing and planning distribution systems that operate in an economical manner with minimal interruption of customer loads. Distributed generation (DG) is expected to play an increasing role in emerging power systems because they use different type of resources and technologies to serve energy to power systems. DG is expected to improve the system reliability as its backup generation. Since DG units are subject to failures as all other generation units, the random behavior of these units must be taken into account in the analysis. Existence of DG units in a distribution system will effect on restoration time of load points. In this paper,...
Application of scheduling models for utility management of process plants and its extension to DG networks
, Article 2008 1st International Conference on Infrastructure Systems and Services: Building Networks for a Brighter Future, INFRA 2008, Rotterdam, 10 November 2008 through 12 November 2008 ; 2008 ; 9781424468874 (ISBN) ; Pishvaie, M. R ; Sharif University of Technology
2008
Abstract
Scheduling models are one of the main parts of computer-aided process design research in recent years. One of the novel applications of scheduling models is their usage for in-site utility management of a process plant. It is very common for huge process plants to provide their utility by themselves; therefore, they shall make decision on utility supply and demand simultaneously. This approach can be extended to other similar systems such as distributed generation networks. In fact, it is possible to consider a DG unit as an autonomous system which is responsible for its energy (heat and power) supply and demand. Of course, for achieving its reliability and dispatchability goals, it would...