55,897 research outputs found
Monitoring and Control of a Smart Distribution Network in Extended Real-Time DMS Framework
No full textBased on recently proposed architectures for smart grids, the authors present a monitoring and control structure for distribution networks. The main idea is that, in a near future, Distribution Network Operators (DNOs) will be able to develop on-line smart functions in the extended real-time framework of daily system operation (approximately every 15-30 minutes). The core of the proposed architecture is an advanced Distribution Management System (DMS) whose task is to assess control functions such as reactive dispatch, voltage regulation, contingency analysis, capability maximization or line switching. The monitoring and control structure proposed for this system includes on-line tools such as GIS interface, topology processor, state estimator, load modelling, load flow and optimal distribution power flow (ODPF), control of active and reactive distributed resources, optimal network reconfiguration. Such architecture can also take advantage of existing communication infrastructures, Automatic Meter Reading (AMR) or Advanced Metering Infrastructure (AMI), which guarantee the availability of two-way communication channels. The paper presents, together with the main outline of the proposed control architecture, the results of an on-going research project with AMET, an Italian city-scale electricity Distribution Company (DisCO) that supplies energy to about 35,000 customers, covering an urban area of about 60,000 inhabitants. Possible applications of DMS will be showed running a novel ODPF algorithm on a real representation of AMET distribution system. Test results will also show how basic smart control functions, such as active and reactive control of distributed resources, are compatible with time requirements of extended real-time DMS framework
Integration of optimal reconfiguration tools in advanced distribution management system
No full textThe paper presents results of a smart grid project, currently on-going, in collaboration with an Italian electricity distribution company (DisCo). The project is aimed at defining new optimization tools to be integrated in the SCADA/DMS that is already implemented within the DisCo control center. In this paper, a DMS architecture that includes Optimal Network Reconfiguration (ONR) functions is presented. ONR, being based on data received through a metering infrastructure and a topology processor, can be performed not only for planning, but also in extended real-time during system operation. Test results are presented for two different operative problems and are carried out on a realistic sized model of a distribution network
A fuzzy-logic approach to preventive maintenance of critical power transformers
No full textIn this paper, a predictive method for the diagnosis of power transformer failures is presented. The approach is
based on the interpretation of Dissolved Gas Analysis (DGA) data using Fuzzy Logic
Operator Training Simulator for power systems: Training evaluation methodologies based on fuzzy logic
No full textOperator training is a relevant aspect of power system operation. In control centers, operators manage the power system through a man machine interface that is a source of further complexity for this critical infrastructure. This paper presents an approach for improving the features of power system Operator Training Simulator (OTS). The OTS program is aimed at training control center operators through the simulation of possible contingency scenarios. The trainees, through simulations, learn to manage the power system during real-time operations and assess on-line dynamic security through the adoption of suitable corrective actions in emergency conditions. Usually, trainees learn only from the experience acquired during the simulation sessions. The OTS is also aimed at improving operator training by adding to the experiential learning the tacit knowledge acquired by senior control center operators. The tacit knowledge can be made explicit and transferred to trainees through well-suited OTS sessions including case studies based on past performed senior operator experiences. The proposed approach is aimed at defining a training evaluation methodology based on fuzzy logic able to reduce the gap between required knowledge and skills and the measured knowledge and skills of operators and to define improvements of each submitted training sessions
L'integrazione di cogenerazione e produzione di idrogeno on-site per la realizzazione di un distretto energetico
No full textA Dynamic Subfilter-scale Stress Model for Large Eddy Simulations Based on Physical Flow Scales
No full textWe propose a new definition of the length scale in an eddy-viscosity model for large-eddy simulations (LES). This formulation extends and generalizes a previous proposal [Piomelli, Rouhi and Geurts, Proc. ETMM10, 2014], in which the LES length scale was expressed in terms of the integral length-scale of turbulence determined by the flow characteristics and explicitly decoupled from the simulation grid; this approach was named Integral Length-Scale Approximation (ILSA). As in the original ILSA, the model coefficient was determined by the user, and required to maintain a desired contribution of the unresolved, subfilter scales (SFS) to the global transport. We propose a local formulation (local ILSA) in which the model coefficient is local in space, allowing a precise control over SFS activity as a function of location. This new formulation preserves the properties of the global model; application to channel flow and backward-facing step verifies its features and accuracy
Large-eddy simulation of a separated flow with a sub-filter scale model based on the integral length-scale
No full textA new sub-filter scale model for large-eddy simulations, which uses a length-scale proportional to the integral scale of the turbulence instead of the grid resolution to parametrize the modelled stresses, will be assessed in the prediction of the flow of a boundary-layer over a rough surface, which includes separation and reattachment
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