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distributed-power-generation
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A comprehensive digital protection scheme for low-voltage microgrids with inverter-based and conventional distributed generations
, Article IEEE Transactions on Power Delivery ; Volume 32, Issue 1 , 2017 , Pages 441-452 ; 08858977 (ISSN) ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Microgrid (MG) protection is one of the main challenges in proliferation of microgrids. Due to limited fault current feeding of inverter-based distributed generations (DGs), in islanded operation of MG, protection problems become more complicated; and, therefore, conventional protection strategies cannot be applied. Hence, new protection methods that are applicable in islanded and grid-connected modes of operation are necessary. In this paper, a comprehensive digital-relay based protection is introduced for the protection of MGs. The proposed method includes protection of lines, distributed generations, and the point of common coupling. The structure and graphical schematic of the proposed...
An Milp model for switch, DG, and tie line placement to improve distribution grid reliability
, Article IEEE Systems Journal ; 2022 , Pages 1-12 ; 19328184 (ISSN) ; Ehsan, M ; Farzin, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Remote controlled switches (RCSs) have the ability to isolate the faulted area from other parts of the distribution system. On the other hand, the dispatchable distributed generators (DDGs) and tie lines can supply the interrupted loads after fault occurrence trough microgrids and reduce the outage time. In this regard, this article proposes a planning model for simultaneous placement of RCSs, DDGs, and tie lines to improve distribution system reliability. The presence of renewable distributed generations (RDGs) and energy storage systems, which have an increasing penetration in today's distribution networks are also considered. Moreover, two different practical load shedding methods are...
A new power management control strategy for a MV microgrid with both synchronous generator and inverter-interfaced distributed energy resources
, Article IEEE International Symposium on Industrial Electronics ; 1- 4 June , 2014 , pp. 2529-2534 ; ISBN: 978-147992399-1 ; Hamzeh, M ; Mokhtari, H ; Karimi, H ; Sharif University of Technology
Abstract
Control strategies of a microgrid which includes both synchronous generators and converter-based distribution generation (DG) units must be designed such that effective operation of the microgrid is achieved. The main objective of this paper is to develop a high performance control strategy for an islanded medium voltage (MV) microgrid consisting of inverter and non-inverter interfaced DG units. A new control method for the synchronous generator in an islanded microgrid is proposed based on a virtual droop scheme. The proposed strategy can effectively manage the real and reactive powers of the microgrid among the inverter and non-inverter based DG units. The steady state and dynamic...
Relay logic for islanding detection in active distribution systems
, Article IET Generation, Transmission and Distribution ; Volume 9, Issue 12 , August , 2015 , Pages 1254-1263 ; 17518687 (ISSN) ; Amraee, T ; Ranjbar, A. M ; Mozafari, B ; Sharif University of Technology
Institution of Engineering and Technology
2015
Abstract
This study presents a passive model to detect islanding conditions of synchronous distributed generation resources in a distribution network or a microgrid. The proposed approach uses the classification and regression tree algorithm for distinguishing between islanding and non-islanding situations. It utilises the rate of change of frequency (ROCOF) and harmonic content of the equivalent reactance seen at the location of distributed generation as input features for decision tree construction. Indeed the thresholds of the proposed input features are extracted by the decision tree algorithm. The output if-then rules of the decision tree algorithm are then utilised to make a new relay logic for...
Multi-objective planning model for integration of distributed generations in deregulated power systems
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 34, Issue 3 , 2010 , Pages 307-324 ; 10286284 (ISSN) ; Ehsan, M ; Sharif University of Technology
2010
Abstract
This paper presents a long-term dynamic multi-objective model for distributed generation investment. The proposed model optimizes three objectives, namely active losses, costs and environmental emissions and determines the optimal schemes of sizing, sitting of DG units and specially the dynamics of investment over the planning period. The Pareto optimal solutions of the problem are found using a GA algorithm and finally a fuzzy satisfying method is applied to select the optimal solution considering the desires of the planner. The solutions of Pareto optimal front are analyzed to extract general useful information for planners about the appropriate DG technologies and placement schemes. The...
IGDT based robust decision making tool for DNOs in load procurement under severe uncertainty
, Article IEEE Transactions on Smart Grid ; Volume 4, Issue 2 , 2013 , Pages 886-895 ; 19493053 (ISSN) ; Ehsan, M ; Sharif University of Technology
2013
Abstract
This paper presents the application of information gap decision theory (IGDT) to help the distribution network operators (DNOs) in choosing the supplying resources for meeting the demand of their customers. The three main energy resources are pool market, distributed generations (DGs), and the bilateral contracts. In deregulated environment, the DNO is faced with many uncertainties associated to the mentioned resources which may not have enough information about their nature and behaviors. In such cases, the classical methods like probabilistic methods or fuzzy methods are not applicable for uncertainty modeling because they need some information about the uncertainty behaviors like...
Imperialist competition algorithm for distributed generation connections
, Article IET Generation, Transmission and Distribution ; Volume 6, Issue 1 , January , 2012 , Pages 21-29 ; 17518687 (ISSN) ; Ehsan, M ; Sharif University of Technology
2012
Abstract
This study proposes an imperialist competition algorithm (ICA) to maximise the benefits of distribution network operators (DNOs) because of the existence of distributed generation (DG) units. The sum of active loss reduction and network investment deferral incentives has been considered as the objective function to be maximised in this study. The optimal location and size of DG units in the network are found considering various techno-economical issues. The application of the proposed methodology in the UK under current Ofgem financial incentives for DNOs is investigated. The ability of the proposed approach in finding the optimal solution is validated by comparing the obtained results with...
Probabilistic dynamic multi-objective model for renewable and non-renewable distributed generation planning
, Article IET Generation, Transmission and Distribution ; Volume 5, Issue 11 , 2011 , Pages 1173-1182 ; 17518687 (ISSN) ; Caire, R ; Hadjsaid, N ; Ehsan, M ; Sharif University of Technology
2011
Abstract
This study proposes a probabilistic dynamic model for multi-objective distributed generation (DG) planning, which also considers network reinforcement at presence of uncertainties associated with the load values, generated power of wind turbines and electricity market price. Monte Carlo simulation is used to deal with the mentioned uncertainties. The planning process is considered as a two-objective problem. The first objective is the minimisation of total cost including investment and operating cost of DG units, the cost paid to purchase energy from main grid and the network reinforcement costs. The second objective is defined as the minimisation of technical risk, including the probability...
Possibilistic evaluation of distributed generations impacts on distribution networks
, Article IEEE Transactions on Power Systems ; Volume 26, Issue 4 , 2011 , Pages 2293-2301 ; 08858950 (ISSN) ; Ehsan, M ; Caire, R ; Hadjsaid, N ; Sharif University of Technology
Abstract
In deregulated power systems, the distribution network operator (DNO) is not responsible for investment in distributed generation (DG) units, and they are just concerned about the best architecture ensuring a good service quality to their customers. The investment and operating decisions related to DG units are then taken by entities other than DNO which are exposed to uncertainty. The DNO should be able to evaluate the technical effects of these uncertain decisions. This paper proposes a fuzzy evaluation tool for analyzing the effect of investment and operation of DG units on active losses and the ability of distribution network in load supply at presence of uncertainties. The considered...
Hybrid immune-genetic algorithm method for benefit maximisation of distribution network operators and distributed generation owners in a deregulated environment
, Article IET Generation, Transmission and Distribution ; Volume 5, Issue 9 , 2011 , Pages 961-972 ; 17518687 (ISSN) ; Ehsan, M ; Caire, R ; Hadjsaid, N ; Sharif University of Technology
Abstract
In deregulated power systems, distribution network operators (DNO) are responsible for maintaining the proper operation and efficiency of distribution networks. This is achieved traditionally through specific investments in network components. The event of distributed generation (DG) has introduced new challenges to these distribution networks. The role of DG units must be correctly assessed to optimise the overall operating and investment cost for the whole system. However, the distributed generation owners (DGOs) have different objective functions which might be contrary to the objectives of DNO. This study presents a long-term dynamic multi-objective model for planning of distribution...
A possibilistic-probabilistic tool for evaluating the impact of stochastic renewable and controllable power generation on energy losses in distribution networks-A case study
, Article Renewable and Sustainable Energy Reviews ; Volume 15, Issue 1 , 2011 , Pages 794-800 ; 13640321 (ISSN) ; Ehsan, M ; Sharif University of Technology
Abstract
This paper proposes a hybrid possibilistic-probabilistic evaluation tool for analyzing the effect of uncertain power production of distributed generations (DGs) on active losses of distribution networks. The considered DG technologies are gas and wind turbines. This tool is useful for distribution network operators (DNOs) when they are faced with uncertainties which some of them can be modeled probabilistically and some of them are described possibilistically. The generation pattern of DG units changes the flow of lines and this will cause change of active losses which DNO is responsible for compensating it. This pattern is highly dependent on DG technology and also on decisions of DG...
A distribution network expansion planning model considering distributed generation options and techo-economical issues
, Article Energy ; Volume 35, Issue 8 , 2010 , Pages 3364-3374 ; 03605442 (ISSN) ; Ehsan, M ; Sharif University of Technology
Abstract
This paper presents a dynamic multi-objective model for distribution network expansion, considering the distributed generations as non-wire solutions. The proposed model simultaneously optimizes two objectives namely, total costs and technical constraint satisfaction by finding the optimal schemes of sizing, placement and specially the dynamics (i.e., timing) of investments on DG units and/or network reinforcements over the planning period. An efficient heuristic search method is proposed to find non-dominated solutions of the formulated problem and a fuzzy satisfying method is used to choose the final solution. The effectiveness of the proposed model and search method are assessed and...
Multi objective distributed generation planning using a binary particle swarm optimization method
, Article 2008 International Conference on Genetic and Evolutionary Methods, GEM 2008, Las Vegas, NV, 14 July 2008 through 17 July 2008 ; 2008 , Pages 140-146 ; 1601320698 (ISBN); 9781601320698 (ISBN) ; Ehsan, M ; Sharif University of Technology
2008
Abstract
With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to utilization of distributed generation. Integration of DG units has been known as an alternative for distribution network reinforcement and purchasing energy from transmission network. Considering these facts, in the planning procedure of DG, determination of optimal sizing and sitting is a very important issue. This work presents a comprehensive framework for integration of distributed generations into a distribution network, regarding various technical and economical issues such as reduction of active power losses, environmental pollutions, investment and running costs while...
A novel method to determine the best size of CHP for an energy hub system
, Article 2011 2nd International Conference on Electric Power and Energy Conversion Systems, EPECS 2011 ; 2011 ; 9781457708060 (ISBN) ; Ranjbar, A. M ; Safe, F ; IEEE; Power and Energy Society (IEEE PES); Abu Dhabi Water and Electricity Authority ; Sharif University of Technology
Abstract
Today, the interest on distributed generation has been increasing, especially due to technical development on generation systems that meet environmental and energy policy concerns. One of the most important distributed energy technologies is Combined Heat and Power (CHP). CHP is small and self-contained electric generation plan that can provide power for household applications, commercial or industrial facilities and hence its applications are overtly increasing. It can reduce power loss and enhance service reliability in distribution systems. One of the influential factors for the users is the purchasing cost of CHP which is largely dependent on its type, capacity and efficiency. Therefore...
CHP optimized selection methodology for a multi-carrier energy system
, Article 2011 IEEE PES Trondheim PowerTech: The Power of Technology for a Sustainable Society, POWERTECH 2011 ; 2011 ; 9781424484195 (ISBN) ; Mozafari, B ; Ranjbar, A. M ; Sharif University of Technology
Abstract
Today, the interest on distributed generation has been increasing, especially due to technical development on generation systems that meet environmental and energy policy concerns. One of the most important distributed energy technologies is Combined Heat and Power (CHP). CHP is small and self-contained electric generation plan that can provide power for household applications, commercial or industrial facilities and hence its applications are overtly increasing. It can reduce power loss and enhance service reliability in distribution systems. One of the influential factors for the users is the purchasing cost of CHP which is largely dependent on its type, capacity and efficiency. Therefore...
CHP optimized selection methodology for an energy hub system
, Article 2011 10th International Conference on Environment and Electrical Engineering, EEEIC.EU 2011 - Conference Proceedings, 8 May 2011 through 11 May 2011 ; May , 2011 , Page(s): 1 - 5 ; 9781424487820 (ISBN) ; Ranjbar, A. M ; Safe, F ; Mahmoodi, M ; Sharif University of Technology
2011
Abstract
Today, the interest on distributed generation has been increasing, especially due to technical development on generation systems that meet environmental and energy policy concerns. One of the most important distributed energy technologies is Combined Heat and Power (CHP). CHP is small and self-contained electric generation plan that can provide power for household applications, commercial or industrial facilities and hence its applications are overtly increasing. It can reduce power loss and enhance service reliability in distribution systems. One of the influential factors for the users is the purchasing cost of CHP which is largely dependent on its type, capacity and efficiency. Therefore...
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...
A multi-objective framework for energy resource scheduling in active distribution networks
, Article International Journal of Ambient Energy ; 2018 , Pages 1-13 ; 01430750 (ISSN) ; Ghazi, R ; Moeini Aghtaie, M ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
Purpose: The purpose of this paper is to investigate the impacts of electric vehicles' (EVs) charging/discharging decisions in energy resources scheduling problem of active distribution networks. Design/methodology/approach: The problem under study is modelled as a two-stage optimisation problem in which the main requirements of EV owners are introduced as an objective function of the first stage. The total energy costs and the emission factor are considered as the main criteria of the second stage. The output generation schedules of distributed generation (DG) technologies together with the charging/discharging schedule of EVs are proposed as decision variables of the energy scheduling...
A multi-objective framework for energy resource scheduling in active distribution networks
, Article International Journal of Ambient Energy ; Volume 40, Issue 5 , 2019 , Pages 504-516 ; 01430750 (ISSN) ; Ghazi, R ; Moeini Aghtaie, M ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
Purpose: The purpose of this paper is to investigate the impacts of electric vehicles' (EVs) charging/discharging decisions in energy resources scheduling problem of active distribution networks. Design/methodology/approach: The problem under study is modelled as a two-stage optimisation problem in which the main requirements of EV owners are introduced as an objective function of the first stage. The total energy costs and the emission factor are considered as the main criteria of the second stage. The output generation schedules of distributed generation (DG) technologies together with the charging/discharging schedule of EVs are proposed as decision variables of the energy scheduling...
An advanced distributed power supply for power electronic transformers
, Article IECON 2007, 33rd Annual Conference of the IEEE Industrial Electronics Society, Taipei, 5 November 2007 through 8 November 2007 ; 2007 , Pages 2038-2043 ; 1424407834 (ISBN); 9781424407835 (ISBN) ; Hekmati, A ; Farhangi, S ; Sharif University of Technology
2007
Abstract
The idea of power electronic transformer (PET), which work with solid-state switches, have been considered noticeably recently. Every power electronic transformer has several parts which each of them needs its own reliable supply voltage. So the appropriate performance of a PET depends on the existence of various proper supply voltages. The distributed power supply (DPS), which can produce several different supply voltages simultaneously with various powers and high reliability, may be the optimum choice available for the supply of different modules of a PET. Additionally, distributed energy generation sources may be used as the alternative source for the PET which in that case it's...