1,721,050 research outputs found
Power System Design Requirements in Presence of Large Clusters of Single Phase Non-Linear Loads
No full textPower quality susceptibility of industrial customers: a paper industry
No full textThe paper deals with power quality (PQ) issues in the specific industrial sector of paper fabrication. In this sector a wide research activity has been performed at customers level in order to identify main susceptibilities of the industrial process and to determine costs associated to PQ events. To this aim data made available both from production process logs and from electricity distributor protection system interruption recordings has been used. Finally, some real figures of possible cost due to PQ problems have been identified and discussed in detail
Estimation of net harmonic currents due to dispersed non linear loads within residential areas
No full textThe paper deals with the problem of estimating net
harmonic currents injected by groups of non linear appliances present
within typical domestic customers mix.
To this aim a simulation based on "bottom-up" approach for accounting the cancellation phenomena among individual contributions hs been adopted and extended. The non linear appliances considered are Television set, Personal Computer, Fluorescent and Compact Fluorescent Lamp. The simulation operation of linear load has been taken into due account in order to simulate more closely real-life conditions. The simulation results are organised in tables which provide the estimate of main net harmonic currents (31th, 5th and 7th) likely to be monitored at the low voltage busbars supplying an end-use area composed exclusively by domestic customers.
The validity of the methodology proposed has been tested by
comparing simulation results with some field measurements from a
raidentidl area investigated
Voltage harmonic distortion in HV grids supplying dc railway lines
No full textThe paper reports some results of an experimental assessment conducted in order to evaluate the effects of various railway system operating conditions on power absorption and voltage harmonic distortion. It is also presented a deterministic methodology for assessing, with acceptable approximation, voltage harmonic
distortion levels such as those commonly evaluated on the basis of few data available for a feasibility study of a new railway power supply system or a change in network configuration. A preliminary comparison between simulation and measurement results is finally reported
Distorsione armonica in un sistema di trasporto elettrificato metropolitano: indagine sulle linee di Roma
No full text
The continous harmonic monitoring of single-phase electronic appliances: desktop PC and printers
No full textThe paper reports some experimental measurement results
concerning harmonic current drawn by PC's and printers. Several samples of equipment have been continuously monitored during their typical operation. For the purpose a custom monitoring system has been used. The continuous harmonic monitoring has permitted an interesting characterization of harmonic spectrum variability that reveals very useful for penetration studies based upon a bottom-up approach
Argos:un modello di simulazione dell'utenza residenziale per lo studio della gestione strategica della domanda di energia
No full textAl fine di ottimizzare le risorse energetiche disponibili e di ridurre gli investimenti per la costruzione di nuovi impianti di produzione, le strategie di controllo della domanda di energia elettrica più diffuse sono applicate in molti Paesi anche al carico residenziale. Per tale settore, però, la previsione dell'impatto della strategia prescelta risulta estremamente complessa in quanto è fondata su una stima della disponibilità dell'utente ad adeguare la propria domanda agli obiettivi proposti. Nel presente articolo viene descritto un modello di simulazione che a partire dal diagramma di carico di un'intera area di utenti residenziali consente di eseguire valutazioni sull'efficacia di politiche di gestione.The paper describes a simulation model of a residential users area to perform some evaluations relevant to different management policies of electric energy demand
Harmonic amplitude and harmonic phase angles monitored in an electrified subway system during rush-hours traffic
No full textThe paper reports some results of a monitoring activity conducted on the subway system of Rome. Both harmonic amplitudes and phase angles have been monitored at one of the five service entrances during the rush-hours traffic. The subway system provides two railway lines supplied at 1.5 kV DC through several AC/DC converter substations. The power supply of the system is provided at medium voltage level (20 kV) from five different connections to the public grid. Fourteen electrical conversion substations provide the total demand of about 20 MW of the system. The obtained results show that the analysis of harmonic amplitude and in particular harmonic phase angles versus time and scatter plots are useful to better characterize this system and to understand the behaviour of such large non linear loads
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