Search results for "conductor"
showing 10 items of 1270 documents
A new model for a safety analysis in a system of earthing systems interconnected through bare‐buried conductors
2009
PurposeThe purpose of this paper is to present a mathematical model for studying the effects of the interconnection through bare‐buried conductors (BBC) of the secondary substations' earthing system of an urban area.Design/methodology/approachThe developed methodology is based on three main points: the solution of the transmission lines' equations for the formulation of a lumped parameters model of a BBC considering the conductive effect; the division of the distribution network into simpler sub‐systems; and the calculation of all the voltages and currents of the medium voltage (MV) network and of the earthing systems using a multiport approach.FindingsThe methodology has been applied to va…
On the effects of HV/MV stations on global grounding systems
2016
The METERGLOB project has faced the issue of the identification of Global Grounding Systems. One of the main point of the problem is to define if an interconnection of single grounding systems gives place to a Global Grounding System in any condition and for every kind of ground fault. This paper focuses the attention on what happens in the case of single line to ground fault inside a HV/MV station whose ground electrode is connected to the cable' shields of the MV lines outgoing the station and supplying the secondary substations of a given area.
Attenuation of low frequency magnetic fields produced by HV underground power cables
2015
High-voltage underground cable systems are becoming more common as the demand for electrical power within urban centers increase, also considering the difficulties in building new overhead power lines in the vicinity of city centers because of authorization issues. Therefore, interest towards the evaluation of magnetic fields produced by high-voltage power lines has been triggered during the last decade and concern about effects on human health of exposure to extra low frequency (ELF) magnetic fields due to power lines has been increasing as well. Hence, the evaluation of the magnetic field produced by underground power cables is important in order to develop methods for mitigating their in…
Electric conduction in solids: a pedagogical approach supported by laboratory measurements and computer modelling environments
2008
In this paper we present a pedagogic approach aimed at modeling electric conduction in semiconductors, built by using NetLogo, a programmable modeling environment for building and exploring multi‐agent systems. ‘Virtual experiments’ are implemented to confront predictions of different microscopic models with real measurements of electric properties of matter, such as resistivity. The relations between these electric properties and other physical variables, like temperature, are, then, analyzed.
A novel implicit correlation for the operative temperature of a PV panel
2012
Abstract The operating temperature of a commercial PV panel strongly affects the electric power output of the devices. The prediction of the operating temperature therefore plays a central role in the economic and energy assessment of PV systems. The authors propose a new implicit correlation that takes into account the standard weather variables but also the regimen of PV panel in terms of the proximity to the maximum power points. Data coming from an experimental setup were processed by using the least squares technique. To validate the reliability of the correlation, a comparison between expected values and data from other common correlations were done. The results show that the regimen …
Optical Fibre Control-Measurement Systems Of Compound HV/HP Electrical Equipment
1988
Responsible electrical equipment should be controlled during the work in care of their high reliability. Traditional control measurement systems cannot fulfil the task because of the hard conditions in which the equipment may operate (various electrical potentials, electromagnetic interferences, changes of temperature, etc.). The development of fibre optic transmission media and fibre optic sensors allows the construction of new control measurement systems for cooperation with such electrical equipment as: converters, generators, treLnsforniens, switch bays, busbards, etc. Those optical fibre structures, composed of bu-ses and sensors are subject of this paper. The main attention is paid to…
The "Livio Scarsi" X-Ray Facility at University of Palermo for Device Testing
2015
In this work, we report on the characteristics of the Livio Scarsi X-ray facility at University of Palermo. The facility is able to produce low energy X rays, within the energy range of 0.1-60 keV, with fluence rates ranging from 105-108 photons/mm2 s. The laboratory is equipped with an innovative digital detection system, based on semiconductor detectors (Si and CdTe detectors), able to provide accurate and precise estimation of the fluence rate, the energy and the exposure of X rays, even at high counting rate conditions. Instrumentation for electrical characterization (DC-AC) of semiconductor devices, for both off-line and on-line (i.e. during the irradiation) measurements, is also avail…
Digital techniques for high-rate high-resolution radiation measurements
2014
Digital pulse processing (DPP) techniques are increasingly used in the development of modern spectroscopic systems. DPP systems, based on direct digitizing and processing of detector signals (preamplifier output signals), ensure higher flexibility, stability, lower dead time, higher throughput and better energy resolution than traditional pulse processing systems. In this work, we present our progress in the development of DPP systems for high-rate high-resolution radiation measurements. An innovative digital system, able to perform multi-parameter analysis (input counting rate, pulse height, pulse shape, event arrival time, etc.) even at high photon counting rates is presented. Experimenta…
Automated Calculation Method to Determine the Output Power Based on the Frequency for Induction Heating IGBT Parallel Inverter
2007
The fact that some inverter topologies used in induction heating applications allow the soft switching working operation lets the progressive replacement of the MOSFET with the IGBT in high power inverters. This is due to two main reasons, the former is the IGBT reliability and the latter is the ratio defined as the price of the component per output power. In this article an automated method to determine the output power based on the frequency of an inverter build with different IGBT is described. To carry out this method is necessary to define the power cycle and to develop the calculation process which determines the energy losses in the working conditions of the resonant parallel inverte…
Semiactive control for floating offshore wind turbines subject to aero-hydro dynamic loads
2011
Wind and wave dynamic loads might cause undesirable vibrations that affect the structure integrity and system performance of floating offshore wind turbines. This paper addresses the problem of dynamic load mitigation by using semiactive control techniques with the tuned liquid column dampers placed on the turbine’s tower. The control law is formulated based on the mixed H2/H∞ methods for ensuring the system stability and reliability. Furthermore, the proposed controller only uses output feedback so as to avoid the dependence on the knowledge of the states of the system. Peer Reviewed