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distributed-power-generation
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A novel islanding detection scheme for synchronous distributed generation using rate of change of exciter voltage over reactive power at DG-side
, Article 2017 Australasian Universities Power Engineering Conference, AUPEC 2017 ; Volume 2017-November , 5 February , 2018 , Pages 1-5 ; 9781538626474 (ISBN) ; Bagheri, M ; Naderi, S. B ; Negnevitsky, M ; Jalilian, A ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Penetration of distributed generation (DG) in distribution networks is rapidly increasing. DGs' application enhances system's reliability and power quality. However, along their benefits, there are some issues. One of the most important issues of DGs' application is the islanding. This paper presents a novel passive islanding detection scheme for synchronous DG based. In the proposed scheme, rate of change of exciter voltage over rate of change of reactive power at the DG-side (dE/dQDG) is taken into account. In reality, the voltage and reactive power of load depend on the exciter of the synchronous generator. Therefore, due to lack of inertia, response of these parameters to small changes...
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...
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...
Determining and optimizing power loss reduction in distribution feeders due to Distributed generation
, Article 2006 IEEE PES Power Systems Conference and Exposition, PSCE 2006, Atlanta, GA, 29 October 2006 through 1 November 2006 ; 2006 , Pages 1914-1918 ; 142440178X (ISBN); 9781424401789 (ISBN) ; Parniani, M ; Sharif University of Technology
2006
Abstract
One of the beneficial impacts of Distributed generation (DG) units on electrical network is power loss reduction in the distribution feeder on which DG is located. In this paper the effect of DG on power losses of a distribution feeder with a combination of uniformly distributed and lumped loads is investigated, and a mathematical model of power loss reduction as a function of DG and the feeder parameters is extracted. Then, based on the derived formula, optimum conditions of utilizing and locating the DG units are obtained. © 2006 IEEE
Controlled islanding for enhancing grid resilience against power system blackout
, Article IEEE Transactions on Power Delivery ; Volume 36, Issue 4 , 2021 , Pages 2386-2396 ; 08858977 (ISSN) ; Amraee, T ; Fotuhi Firuzabad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
This paper proposes a transient stability constrained controlled islanding (TSC-CI) approach against cascading events in power systems. Using the wide area measurements, the proposed islanding algorithm is implemented regarding the actual dynamic conditions of the resulted islands. Since the main concern, right after the execution of controlled network splitting, is the transient stability of synchronous machines, a transient energy function is utilized for proper network partitioning. The proposed transient stability criterion is expressed as a function of the transfer impedance between each pair of generators in the resulted islands. Transfer impedance between each pair of coherent...
Reliability assessment of distribution system with the integration of photovoltaic and energy storage systems
, Article Sustainable Energy, Grids and Networks ; Volume 28 , 2021 ; 23524677 (ISSN) ; Esmaeili Nezhad, A ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
With the current focus on energy and the environment, efficient integration of renewable energies, especially solar energy into power systems, is becoming indispensable. Moreover, to fully capture solar potentials and to recognize the unique characteristics associated with solar energy in power systems reliability assessment, a profound investigation is needed. Accordingly, this paper attempts to establish a comprehensive analytical approach for modeling the reliability of a hybrid system (Photovoltaic (PV) system with Energy Storage System (ESS)). To this end, the output of the PV system is modeled by a multi-state model, and the ESS system is modeled as a two-state Markov model. Moreover,...
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...
A game theoretic framework for DG optimal contract pricing
, Article 2013 4th IEEE/PES Innovative Smart Grid Technologies Europe, ISGT Europe 2013 ; 2013 ; 9781479929849 (ISBN) ; Rajabi-Ghahnavieh, A ; Zahedian, A ; Sharif University of Technology
2013
Abstract
This paper presents a new approach based on multi leader follower game in order to find the optimal contract price of distributed generation in distribution network considering competition among them. The leader problems correspond to the independent DG units who decide to maximize the individual profits, while the follower problem refers to the distribution company (DisCo) which seeks the minimization of the payments incurred in attending the expected demand while satisfying network constraints. Disco can purchase energy either from the transmission network through the substations or from the DG units within its network. The DisCo minimization problem acts as a constraint into the each DG...
U-shaped energy loss curves utilization for distributed generation optimization in distribution networks
, Article Journal of Zhejiang University: Science C ; Volume 14, Issue 11 , 2013 , Pages 887-898 ; 18691951 (ISSN) ; Ehsan, M ; Nouri, H ; Sharif University of Technology
2013
Abstract
We propose novel techniques to find the optimal location, size, and power factor of distributed generation (DG) to achieve the maximum loss reduction for distribution networks. Determining the optimal DG location and size is achieved simultaneously using the energy loss curves technique for a pre-selected power factor that gives the best DG operation. Based on the network's total load demand, four DG sizes are selected. They are used to form energy loss curves for each bus and then for determining the optimal DG options. The study shows that by defining the energy loss minimization as the objective function, the time-varying load demand significantly affects the sizing of DG resources in...
A decentralized self-adjusting control strategy for reactive power management in an islanded multi-bus MV microgrid
, Article Canadian Journal of Electrical and Computer Engineering ; Volume 36, Issue 1 , 2013 , Pages 18-25 ; 08408688 (ISSN) ; Mokhtari, H ; Karimi, H ; Sharif University of Technology
2013
Abstract
This paper presents a decentralized self-adjusting reactive power controller for the autonomous operation of a multi-bus medium voltage (MV) microgrid. The main objective of the proposed control strategy of each distributed generation (DG) unit is to compensate the reactive power of its local loads and to share the reactive power of the nonlocal loads among itself and other DG units. The proposed control strategy includes an improved droop controller whose parameters are adjusted according to the reactive power of the local loads. A virtual inductive impedance loop is augmented to the voltage controller to enhance the steady state and transient responses of the proposed reactive power...
A robust two-degree-of-freedom control strategy for an islanded microgrid
, Article IEEE Transactions on Power Delivery ; Volume 28, Issue 3 , 2013 , Pages 1339-1347 ; 08858977 (ISSN) ; Karimi, H ; Sharif University of Technology
2013
Abstract
This paper presents a new robust control strategy for an islanded microgrid in the presence of load unmodeled dynamics. The microgrid consists of parallel connection of several electronically interfaced distributed generation units and a local load. The load is parametrically uncertain and topologically unknown and, thus, is the source of unmodeled dynamics. The objective is to design a robust controller to regulate the load voltage in the presence of unmodeled dynamics. To achieve the objective, the problem is first characterized by a two-degree-of-freedom (2DOF) feedback-feedforward controller. The 2DOF control design problem is then transformed to a nonconvex optimization problem....
Optimal siting of DG units in power systems from a probabilistic multi-objective optimization perspective
, Article International Journal of Electrical Power and Energy Systems ; Volume 51 , 2013 , Pages 14-26 ; 01420615 (ISSN) ; Hosseini, S. H ; Moeini Aghtaie, M ; Arabali, A ; Sharif University of Technology
2013
Abstract
Along with the increasing demand for electrical power, distributed generations (DGs) have so far found their pivotal roles in the restructured environment of power distribution systems. As an indispensable step toward a more reliable power system, the DGs optimal allocation strategy, deemed to be the most techno-economically efficient scheme, comes to the play and is profoundly taken under concentration in this study. This paper devises a comprehensive multi-objective (MO) optimization approach by which all the crucial and maybe contradictory aspects of great influence in the placement process can be accounted for. Total imposed costs, total network losses, customer outage costs as well as...
Proposed flux-based optimization method for determination of minimum superconductor material in shield-type superconducting fault current limiters
, Article Scientia Iranica ; Volume 19, Issue 6 , December , 2012 , Pages 1843-1849 ; 10263098 (ISSN) ; Vakilian, M ; Fardmanesh, M ; Sharif University of Technology
2012
Abstract
Distributed power generation and an ever growing load demand have caused the current level of fault to exceed the nominal rating of power system devices, and fault current limiters are needed even more. The Superconducting Fault Current Limiter, SFCL, forms an efficient category of current limiters. The superconductor part in SFCLs is the most costly part of the device, and minimizing its volume, while maintaining the required characteristics of the device, would be very beneficial. In this work, using a Simulated Annealing optimization algorithm, a method has been proposed to determine minimum required bulk superconductor material in inductive shield-type SFCL structures. The flux linkage...
A dynamic fuzzy interactive approach for DG expansion planning
, Article International Journal of Electrical Power and Energy Systems ; Volume 43, Issue 1 , 2012 , Pages 1094-1105 ; 01420615 (ISSN) ; Ehsan, M ; Fattahi Meyabadi, A ; Sharif University of Technology
2012
Abstract
This paper presents a dynamic multi objective model for distribution network expansion, considering the distributed generators (DGs) and network reinforcements. The proposed model simultaneously optimizes three objective functions namely, total cost, emission cost and technical satisfaction (voltage profile) by finding the optimal schemes of timing, sizing, placement and DG technologies in a long term planning period (dynamic planning). The importance of each objective function can be changed in the interactive steps. The calculation algorithm is based on Chaotic Local Search with Modified Honey Bee Mating Optimization (CLSMHBMO). The effectiveness of the proposed model and the calculation...
Neuro-fuzzy islanding detection in distributed generation
, Article 2012 IEEE Innovative Smart Grid Technologies - Asia, ISGT Asia 2012, 21 May 2012 through 24 May 2012 ; May , 2012 ; 9781467312219 (ISBN) ; Sheikholeslamzadeh, M ; Ranjbar, A. M ; Mozafari, B ; Sharif University of Technology
2012
Abstract
Islanding detection methods are divided into three main groups as remote, active and passive. Although passive schemes have larger Non Detection Zones (NDZ) relative to other schemes, they are more used in utilities due to their low costs and less PQ problems than other schemes. Passive Schemes are based on the measurements of passive system parameters. These parameters are measured at the point of common coupling (PCC). A new approach in passive techniques is the use of data-mining to classify the system parameters. In this paper, massive indices are collected by simulation of a practical distribution system in PSCAD/EMTP environment. These indices include voltage, frequency, current,...
A novel SVM approach of islanding detection in micro grid
, Article 2012 IEEE Innovative Smart Grid Technologies - Asia, ISGT Asia 2012, 21 May 2012 through 24 May 2012 ; May , 2012 ; 9781467312219 (ISBN) ; Sheikholeslamzadeh, M ; Ranjbar, A. M ; Mozafari, B ; Sharif University of Technology
2012
Abstract
Passive islanding detection schemes are more used in utilities due to their low costs and less harmonic problems although having larger Non Detection Zones (NDZ) relative to other schemes. Passive system measurements at the point of common coupling (PCC) are the basis of this scheme. A new approach in passive techniques is the use of intelligent based methods in data-mining to classify the system parameters which affect the islanding detection. As a result, by finding an efficient and robust data-mining algorithm, the passive schemes problem, which is their relatively large NDZ, will be minimized. In this paper, massive measurements are collected by simulation of IEEE standard distribution...
Optimal DG sizing in primary distribution feeders using dynamic programming approach
, Article 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings, 18 May 2012 through 25 May 2012, Venice ; 2012 , Pages 371-375 ; 9781457718281 (ISBN) ; Kenari, M. T ; Mehrasa, M ; Sharif University of Technology
IEEE
2012
Abstract
Distributed generation (DG) corresponds to the application of small generating units which are the set up in distribution systems or near load centers. Utilization of DG influences various operational indices of the distribution feeders such as feeder loading, electrical losses and voltage profile. In addition, use of DG in its appropriate size is an essential tool to attain the DG maximum potential advantages. In this paper, an optimization method is proposed to determine the optimal size of DG in the distribution system. This method considers the system technical factors such as losses, voltage profile and loading of the primary distribution system feeders. The optimization process is...
Voltage stability improvement through centralized reactive power management on the Smart Grid
, Article 2012 IEEE PES Innovative Smart Grid Technologies, ISGT 2012, 16 January 2012 through 20 January 2012 ; 2012 ; 9781457721588 (ISBN) ; Abbaspour-Tehrani Fard, A ; Dobakhshari, A. S ; Ranjbar, A. M ; Sharif University of Technology
2012
Abstract
With the increasing penetration of renewable energies as distributed generation (DG) in power systems, technical problems arise in both distribution and transmission system level. Voltage rise is the main barrier for connection of DGs in rural areas, while excessive reactive power demand from transmission system is the major concern for Transmission System Operators (TSO). Here, a centralized control scheme based on the Smart Grid is proposed to reduce the impact on the transmission system voltages and improve its stability, while mitigating the voltage rise issue in the distribution network. Reactive power output of DGs, substation capacitors and tap setting of transmission transformer are...
μ-Synthesis control for an islanded microgrid with structured uncertainties
, Article IECON Proceedings (Industrial Electronics Conference), 7 November 2011 through 10 November 2011 ; November , 2011 , Pages 3064-3069 ; 9781612849720 (ISBN) ; Karimi, H ; Sharif University of Technology
2011
Abstract
This paper presents a robust control scheme for an islanded microgrid in the presence of structured uncertainties. The microgrid consists of parallel connection of two Distributed Generation (DG) units and a passive load. The DG units are connected to the passive load by using the power electronics converters. The microgrid model is structurally uncertain due to the large perturbations in the load parameters. To deal with the uncertainties, a Linear Fractional Representation (LFR) of the parametrically uncertain system is obtained. To achieve robust performance, the μ-synthesis approach is applied to the derived LFR model to design a μ controller. The resultant controller is structurally...
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...