Search results for "Transmission network"
showing 9 items of 9 documents
Evaluation of HIV transmission clusters among natives and foreigners living in Italy
2020
We aimed at evaluating the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and migrants living in Italy, diagnosed between 1998 and 2018. Phylogenetic analyses were performed on HIV-1 polymerase (pol) sequences to characterise subtypes and identify MTCs, divided into small (SMTCs, 2&ndash
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 …
A method for the evaluation of fault current distribution in complex high voltage networks
2015
Abstract The paper presents a method for the study of large interconnected earthing systems in High Voltage networks. The mathematical model proposed for calculating the distribution of the Single-line-to-Earth fault current is useful for a methodical and accurate analysis of complex systems having meshed configuration and more sources, and has practical application for the Transmission System Operator. Two case studies are provided. The first one considers a fault occurring inside and outside a station in a real 220 kV transmission network. In the second example, the proposed methodology is compared with the classical “Double-sided elimination” method.
A novel approach to current transformer characterization in the presence of harmonic distortion
2009
The current transformer (CT) performance under distorted waveform conditions is usually characterized by means of the frequency-response test. In this paper, a new way to characterize CTs, closer to real operation conditions, is proposed. The harmonic phase-angle and ratio errors are measured using a nonsinusoidal current composed of fundamental and one harmonic with adjustable phase shift. The new method was tested by determining the performance of two metering class CTs commonly used by the Italian power company. The errors measured using the proposed approach are larger than the ones obtained with the frequency response. This result suggests that the frequency-response approach for the e…
Steady-state security analysis on the transmission grid for various scenarios of wind generation in Sicily
2009
The proposed paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. After describing the current state of wind energy generation in Sicily, the paper reports and comments the results of the steady-state security analysis done for various scenarios of wind penetration. For each scenario (maximum and minimum load conditions), the redistribution of power flows on the transmission network, the voltage profiles at nodes, the analysis of contingencies and losses variations are reported.
Characterization of clamp-on current transformers under nonsinusoidal conditions
2009
This paper reports the performance of clamp-on current transformers under nonsinusoidal conditions. A set of experimental measurements helped to determine the ratio and the phase errors under two conditions: 1) sinusoidal excitation with frequencies from 45 to 1000 Hz and 2) nonsinusoidal excitation using the fundamental frequency and one harmonic, with adjusted phase shift. It was found that ratio and phase errors are affected by the phase angle between the harmonic and the fundamental and the harmonic amplitude. The effects of conductor location in the current transformer's window and of the air-gap width were also investigated. It was concluded that harmonic phase and ratio errors measur…
Measurement uncertainty impact on simplified load flow analysis in MV smart grids
2018
This work is focused on the measurement uncertainty impact on load flow analysis in medium voltage (MV) distribution networks. In more detail, the paper presents the uncertainty evaluation of a simplified load flow algorithm, which is based on the load power measurements at each secondary substation and one voltage measurement at the slack bus (i.e. the voltage at the MV bus bars of the primary substation). To reduce the costs of the monitoring system, the load flow algorithm makes use of LV load power measurements for all the substations except those of MV users, where MV transducers are usually already installed. The uncertainties on the algorithm input quantities (load powers and slack b…
Storage to Avoid Congestion and Release Solar Power for Vietnam Power System: The Case Studies of a High Voltage Transmission Network in Ninh-Thuan P…
2023
The energy transition is taking place in a diverse manner around the world, and the achievement of clean energy goals could follow very different pathways. However, two recent crises of Covid-19 and Ukraine hit all markets, especially the energy market, thus influencing strongly the energy transition in most countries including Southeast Asian countries. Southeast Asian countries are now playing a prominent role in the supply chain of clean energy sources, with good examples of different renewable energy growths in a very constrained environment of resources. One of these drivers is that the proper Feed-In Tariffs (FIT) mechanism has laid the foundation for the rapid development of renewabl…
Genomic Analysis of Bacterial Outbreaks
2016
The study of outbreaks of infectious diseases has been revolutionized by the current availability of fast and efficient, high-throughput methods capable of yielding the nucleotide sequence of complete genomes of viruses and bacteria within a few days, or even hours. These methods are replacing previous molecular techniques which have been used for the past 30 years, although many of them are still the usual approach for many such investigations. Here we review the major technologies currently in use for high-throughput sequencing of bacterial genomes emphasizing their advantages and drawbacks for the analysis of outbreaks. The use of more efficient methods does not necessarily mean that all…