Search results for "grid"
showing 10 items of 792 documents
Web Services Specific Security Standards
2014
Abstract In this paper are described the aspects regarding the security within OGSA framework, introducing WS-Security standard – OASIS standard for Web Services security. There are approached the security aspects of the OGSA environment for the delivered architectures P2P – ‘Peer-to-Peer’ and there are presented the recent initiatives for creating a specific and adapted environment OGSA for the applications P2P and the specific security demands of these transactions. Furthermore, there are exposed aspects regarding the mobility of services and resources in the P2P context, with the conditions of applying WSRF framework, derived from OGSA to the P2P environments, SOA processes in P2P enviro…
Enhanced islanding detection in smart interface protection systems of distributed generation
2021
The widespread presence of distributed generators (DGs) and storage systems (DSSs) in electricity grids has increased the risk of islanding occurrence. This phenomenon must be suitably managed by Distribution System Operators (DSO), in order to avoid adverse situations, in terms of grid-protection problems, equipment damage, safety hazards, power quality problems and so on. Currently anti-islanding protection functions are handled by interface protection systems (IPSs), which are built in accordance with relevant standards for DGs and DSSs connection to power systems. However, some problems may occur in case of operation within the so-called non detection zone (NDZ). This paper presents an …
Review of machine to machine communication in smart grid
2016
Machine to machine communication (M2M) is a communication architecture that enables heterogeneous devices to interact with each other without human intervention. Smart Grid (SG) is one of the many applications areas in the M2M communication. Smart Grid demands advanced communication infrastructure for two-way communications between devices deployed at various locations in energy generation, transmission, distribution and consumption. The billions of electronic devices connected to the Smart Grid pose a big challenge to grid communication. Therefore, a feasible solution to efficient M2M has to overcome challenges of energy efficiency of connected devices, interoperability, coverage area, int…
Analysis and Validation of Learning Technology Models, Standards and Specifications
2010
The paper presents a model for the analysis, comparison and validation of standards, specifications and in particular reference models in the field of Technology Enhanced Learning (TEL). The Reference Model Analysis Grid (RMAG) establishes categories of reference models and standards. Based on those categories, a set of criteria for the analysis and validation of standards was elaborated as a part of the ICOPER project that aims at interoperable open content for competency-based TEL. The analysis of standards in this context is targeted at developing a set of validated approaches that lead to a new reference model. Four standards were investigated, taking into account a broad range of aspec…
Semantic Agent Programming Language (S-APL): A Middleware Platform for the Semantic Web
2008
The agent-based approach is an effective one for building middleware interconnecting distributed heterogeneous resources and providing semantic interoperability among them. On the other hand, agents need the semantic Web technologies for flexible yet effective coordination among them with a particular issue of enabling agents to communicate not only about the domain but also about their own abilities, goals, and present and intended actions. This paper describes semantic agent programming language (SAPL)intended to be a core middleware language for the semantic Web. S-APL integrates the semantic description of the domain resources with the semantic prescription of the agents' behaviors. Add…
Autonomous Demand Side Management of Electric Vehicles in a Distribution Grid
2019
The electricity demand due to the increasing number of EVs presents new challenges for the operation of the electricity network, especially for the distribution grids. The existing grid infrastructure may not be sufficient to meet the new demands imposed by the integration of EVs. Thus, EV charging may possibly lead to reliability and stability issues, especially during the peak demand periods. Demand side management (DSM) is a potential and promising approach for mitigation of the resulting impacts. In this work, we developed an autonomous DSM strategy for optimal charging of EVs to minimize the charging cost and we conducted a simulation study to evaluate the impacts to the grid operation…
Key EU DEMO plant and building layout criteria
2021
Abstract An early attention to the layout of both plant site and its buildings is essential in a complex plant under preliminary design as DEMO in order to meet the assigned targets, namely i) the licensing requirements ii) a good availability in delivery electricity to the grid. The layout definition has to follow several criteria that become more complex and stringent for nuclear buildings, e.g. functional, maintenance, fire protection, safety, human factors, shielding, and remote handling. The criterion As Low As Reasonable Achievable, with respect to the dose to the staff, has to be applied in design, operation, maintenance and decommissioning phases. The tokamak building, where several…
Real-Time Power Flow Monitoring and Control System for Microgrids Integration in Islanded Scenarios
2019
This article presents an enhanced system for real-time power flow monitoring and control (PFMC) for microgrids integration in medium-voltage (MV) distribution networks. The developed solution includes both system architecture and the monitoring and control algorithms, and it has low implementation and installation costs. It is based on the use of hardware and software solutions previously proposed by the authors, i.e., a distributed measurement, a control and communication architecture, and a supervisory control and data acquisition (SCADA) software, which have been enhanced and integrated for the considered application. The SCADA implements a load flow (LF) algorithm for real-time power fl…
Quasi-continuous-time impurity solver for the dynamical mean-field theory with linear scaling in the inverse temperature
2013
We present an algorithm for solving the self-consistency equations of the dynamical mean-field theory (DMFT) with high precision and efficiency at low temperatures. In each DMFT iteration, the impurity problem is mapped to an auxiliary Hamiltonian, for which the Green function is computed by combining determinantal quantum Monte Carlo (BSS-QMC) calculations with a multigrid extrapolation procedure. The method is numerically exact, i.e., yields results which are free of significant Trotter errors, but retains the BSS advantage, compared to direct QMC impurity solvers, of linear (instead of cubic) scaling with the inverse temperature. The new algorithm is applied to the half-filled Hubbard mo…
Mott transitions in ternary flavor mixtures of ultracold fermions on optical lattices
2009
Ternary flavor mixtures of ultracold fermionic atoms in an optical lattice are studied in the case of equal, repulsive on-site interactions U>0. The corresponding SU(3) invariant Hubbard model is solved numerically exactly within dynamical mean-field theory using multigrid Hirsch-Fye quantum Monte Carlo simulations. We establish Mott transitions close to integer filling at low temperatures and show that the associated signatures in the compressibility and pair occupancy persist to high temperatures, i.e., should be accessible to experiments. In addition, we present spectral functions and discuss the properties of a ``semi-compressible'' state observed for large U near half filling.