Search results for: N. D. Hatziargyriou
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The present paper proposes a method for enhancing the resilience of distribution systems that are exposed frequently to disastrous conditions. In case of a fault, the distribution system is sectionalized into self-sufficient microgrids in order to prevent a possible spread of the fault with the minimum load shedding of the islanded portion of the distribution system. The design of self-sufficient...
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Journal of Modern Power Systems and Clean Energy > 2017 > 5 > 2 > 169-176
Microgrids can operate either interconnected to the utility grid or disconnected forming an island. The transition between these modes can cause transient overcurrents or power oscillations jeopardizing the equipment safety or the system stability. This paper proposes a local multi agent control method for a seamless transfer between the islanded and interconnected modes of operation with agents implemented...
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Lecture Notes in Computer Science > Artificial Neural Networks – ICANN 2006 > Neural Computing in Energy Engineering (Special Session) > 726-735
In this paper, an advanced system based on artificial intelligence and fuzzy logic techniques is developed to predict the wind power output of a wind farm. A fuzzy logic model is applied first to check the reliability of the numerical weather predictions (NWPs) and to split them in two sub-sets, of good and bad quality NWPs, respectively. Two Radial Basis Function (RBF) neural networks, one for each...
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IEEE Transactions on Sustainable Energy > 2015 > 6 > 4 > 1485 - 1493
In this paper, a control strategy for the participation of photovoltaic (PV) systems in frequency regulation is suggested. A number of strings from every inverter of a PV system are kept as reserve by disconnecting them through dc-relays. Hence, as the control algorithm monitors the grid frequency, it reconnects or disconnects strings, according to the occurring frequency deviations (negative and...
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This paper deals with the problem of distribution network planning (DNP) considering distributed generation (DG) and uncertainties. The involved uncertainties are the output power of wind and PV generation, the future load growth in the planning period and the evolution of the electricity prices. A Tabu search (TS)-based method with an embedded probabilistic power flow analysis is developed in order...
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Modern power systems are characterized by high uncertainty. The paper presents a method for a network constrained setting of control variables in independent or weakly coupled power zones based on probabilistic load flow (plf) analysis. Plf is applied in order to provide the complete spectrum of all probable values of the state and output variables, such as bus voltages. The network is divided into...
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MedPower 2014 > 1 - 7
Microgrids are low-voltage (LV) distribution networks comprising various distributed generators (DGs), storage devices, and controllable loads that can operate either interconnected or isolated from the main distribution grid as a controlled entity. In this paper, two real microgrids-one interconnected and one autonomous- are set under study. Both of the systems are located at the pilot site of Meltemi,...
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MedPower 2014 > 1 - 4
This paper presents the offshore floating wind technology. The fixed-bottom offshore wind parks are developed for electricity production in Northern European countries where shallow waters exist. The exploitation of the vast wind resources in larger water depths is very significant for the offshore wind sector expansion, thus floating wind turbines are needed.
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MedPower 2014 > 1 - 8
DC Microgrids (DC MGs) gain popularity as they present attractive features such as: high system efficiency, high power quality, reduced cost, reduced power conversions and less complex control. This paper presents a local control strategy of a DC MG consisting of a fuel cell and a composite energy storage system that includes super capacitors and a battery bank. The control strategy is based on the...
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This paper presents a power flow based approach to transmission fixed cost allocation problem in a pool based electricity market that takes into consideration N-1 secure annual operation. In this pricing approach, the cost of each facility is linked to the highest possible power flow a facility may face under a contingency situation in a year. Charges for each facility are based on the facility usage...
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This paper proposes an enhanced recursive harmony search (HS) algorithm for the solution of the static transmission expansion planning (TEP) in deregulated environment considering security constraints. The modification of the recursive HS method in comparison to the traditional HS algorithm includes: i) the introduction of a variable bandwidth in the memory consideration and the pitch adjustment phases...
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This paper presents the results of a demonstration focusing on consumers management in Greece. The application uses distributed intelligence and more specific Multi Agent Systems in order to allow the active management and cooperation between the home appliances. The scenario presented in this paper focuses on the provision of ancillary services and more specific congestion management of distribution...
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This paper proposes an improved harmony search (HS) algorithm for the solution of the static transmission expansion planning (TEP) problem with security constraints. The modification of this method in comparison to the original harmony search algorithm includes the introduction of a variable bandwidth in the memory consideration and the pitch adjustment phase for the selection of the new harmony vector...
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The restructuring and deregulation has exposed the transmission planner to new objectives and uncertainties. As a result, new criteria and approaches are needed for transmission expansion planning (TEP) in deregulated electricity markets. This paper proposes a new market-based approach for TEP. An enhanced differential evolution (EDE) model is proposed for the solution of this new market-based TEP...
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This paper analyzes the behavior of the wind and examines the impact of varying levels of wind penetration on the ancillary services and unit commitment costs for conventional oil-fired generation for an isolated system. The application is based on data for the island of Crete. Three years of minute-by-minute telemetered load, wind speed, and wind generation data were deployed. The study also analyzes...
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This paper describes an algorithm to deal with the scheduling problem in the Microgrids management. The proposed implementation includes the modelling of domestic electrical devices and takes into account the variable electricity market price.
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This paper exams the large distribution power system of Greece with high integration of Renewable Energy Resources (RES) and Electrical Vehicles (EV) using Probabilistic Load Flow (PLF) techniques. These techniques provide Cumulative Density Functions (CDF) of branch power flows, node voltages and active power line losses with large variations of RES and EV integration. When different charging strategies...
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Transmission system planning in deregulated markets often includes a set of proposed alternative expansion schemes instead of a single optimal network solution. In this paper, a methodology is proposed for the economic evaluation of alternative transmission expansion plans, based on several indices that measure the market performance of the expansion schemes. The proposed methodology can assess in...
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This paper presents and analyses several approaches for transmission cost allocation in a centralized pool based electricity market environment that includes composite embedded/marginal transmission pricing mechanisms. The revenue from marginal cost based remuneration (MBR) necessitates supplementary charges; thus it is required to identify the contribution of individual generators and loads to the...
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European Transactions on Electrical Power > 21 > 2 > 1217 - 1237
The effect of the use of a Microgrid Central Controller (MGCC) to achieve co‐ordinated operation of various DG sources, storage devices and controllable loads with regards to the potential economic benefits and the power losses avoided in the local network is presented. Additionally, the effect of connecting numerous typical Microgrids in a typical medium voltage (MV) network regarding power losses...
