Search results for "Grid"
showing 10 items of 792 documents
Cluster-based RF fingerprint positioning using LTE and WLAN signal strengths
2017
Wireless Local Area Network (WLAN) positioning has become a popular localization system due to its low-cost installation and widespread availability of WLAN access points. Traditional grid-based radio frequency (RF) fingerprinting (GRFF) suffers from two drawbacks. First it requires costly and non-efficient data collection and updating procedure; secondly the method goes through time-consuming data pre-processing before it outputs user position. This paper proposes Cluster-based RF Fingerprinting (CRFF) to overcome these limitations by using modified Minimization of Drive Tests data which can be autonomously collected by cellular operators from their subscribers. The effect of environmental…
Creating a semantically-enhanced cloud services environment through ontology evolution
2014
Currently, the availability of Web resources has grown enormously to the point that whatever a user needs at a given moment can potentially be found on the Internet. These resources are not limited to data items anymore, functionality delivered through some sort of service architectural model is also offered on the Internet. In the last few years, cloud computing has emerged as one of the most popular computing models to provide services over the Internet. However, as the number of available cloud services increases, the problem of service discovery and selection arises. Experience indicates that semantic technologies can provide the basis for enhanced and more precise search processes. In …
Simulation of photovoltaic installation connected to the grid with storage system
2017
Abstract In the present paper, a new approach for the management of energy resources in a research laboratory is proposed and evaluated. A simulation study for the photovoltaic (PV) installation was conducted under the Tunisian-Italian cooperation project DE.DU.ENER.T, using renewable energy and economic criteria. The aim of the study is to improve the energy efficiency in order to minimize the electricity cost consumed in the laboratory. A Hybrid Renewable Energy System consisting of a photovoltaic field of 12KWc was installed to reduce the exorbitant bills, due to intensive energy equipment such as drying ovens and workstations, using sustainable, green and clean sources. In addition, a s…
A new low cost power line communication solution for smart grid monitoring and management
2018
Modern smart grids require the improvement of measurement and communication infrastructures of distribution networks, at both medium voltage (MV) and low voltage (LV) levels. Distributed sensing and measurement systems are needed to provide all necessary data for grid monitoring, control and management, as well as for the implementation of a number of smart functionalities, such as remote control of distributed generators (DGs), real time analysis of power flows, automatic meter reading (AMR), demand side management (DSM), grid automation and so on [1]-[6]. Acquired network data include typical electrical network quantities and status variables (such as powers, voltages, currents, switches …
On the Interconnections of HV–MV Stations to Global Grounding Systems
2019
The interconnection of grounding systems of HV-MV stations via the armors of medium voltage cables, is herein analyzed to verify the effects on touch voltages in ground-fault conditions. The major contributions of this paper are two: the analysis of the impact of an HV ground-fault on a global grounding system (GGS), and the analysis of the parameters that may affect safety due to the interconnection between HV-MV stations and the GGS. The authors have analyzed cases when the connection of an HV-MV station to a GGS improves safety, and then may introduce hazards under ground-fault conditions. Two main issues are herein discussed: 1) the transfer of dangerous voltages to substations, due to …
Teletraffic Engineering for Direct Load Control in Smart Grids
2018
International audience; The traditional paradigm for power grid operation is to continuously adapt energy production to demand. This paradigm is challenged by the increasing penetration of renewable sources, that are more variable and less predictable. An alternative approach is the direct load control of some inherently flexible electric loads to shape the demand. Direct control of deferrable loads presents analogies with flow admission control in telecommunication networks: a request for network resources (bandwidth or energy) can be delayed on the basis of the current network status in order to guarantee some performance metrics. In this paper we go beyond such an analogy, showing that u…
A review of thermochemical energy storage systems for power grid support
2020
Power systems in the future are expected to be characterized by an increasing penetration of renewable energy sources systems. To achieve the ambitious goals of the “clean energy transition”, energy storage is a key factor, needed in power system design and operation as well as power-to-heat, allowing more flexibility linking the power networks and the heating/cooling demands. Thermochemical systems coupled to power-to-heat are receiving an increasing attention due to their better performance in comparison with sensible and latent heat storage technologies, in particular, in terms of storage time dynamics and energy density. In this work, a comprehensive review of the state of art of theore…
Effect of Demand Side Management on the Operation of PV-Integrated Distribution Systems
2020
In this new era of high electrical energy dependency, electrical energy must be abundant and reliable, thus smart grids are conducted to deliver load demands. Hence, smart grids are implemented alongside distributed generation of renewable energies to increase the reliability and controllability of the grid, but, with the very volatile nature of the Distributed Generation (DG), Demand Side Management (DSM) helps monitor and control the load shape of the consumed power. The interaction of DSM with the grid provides a wide range of mutual benefits to the user, the utility and the market. DSM methodologies such as Conservation Voltage Reduction (CVR) and Direct Load Control (DLC) collaborate i…
A new PLC-based smart metering architecture for medium/low voltage grids: Feasibility and experimental characterization
2018
Abstract This paper investigates the feasibility of a smart metering architecture for modern power grids in the smart cities framework. A particular focus is made on Automatic Meter Reading, with the aim of facing some costs and safety drawbacks of current solutions (such as dependence from wireless communication providers, reliability problems in bad weather conditions, and exposition to cyber-attacks). The proposed architecture exploits power line communications (PLC) at both low and medium voltage level, thanks to new devices and an innovative medium voltage PLC coupling system. The new coupling solution and the whole smart metering architecture are experimentally verified in a wide freq…
A Novel Symmetrical Boost Modulation Method for qZS-based CHB Inverters
2020
Quasi-Z-source cascaded H-bridge (qZS-CHB) inverters are arising as an innovation in the field of the electrical conversion for PV applications. This type of converters inherit the advantages of multilevel inverters and single-stage configuration. In this context, this paper proposes a novel symmetrical boost modulation strategy for qZS CHB multilevel inverters to increase the performance in terms of voltage stresses and power quality. The novelty lies in the adoption of a different concept to generate the shoot-through states compared to the traditional methods. Simulation analysis in a grid connected application to evaluate the benefits of this boost method is performed in the MATLAB/PLEC…