1,721,160 research outputs found
Multiconductor cell analysis of shunt compensated cable lines
No full textThe author has already presented some papers [1, 2] which allow studying cable systems by means of the multiconductor cell analysis (MCA). This method considers the cable system in its real asymmetry without simplified and approximated hypotheses. The multiconductor matrix procedure based on the use of admittance matrices, which account for the line cells (with earth return currents), different types of shield bonding, possible multiple circuits (single and double circuits or more), allows predicting the steady-state regime of any cable system. In previous papers, these matrix algorithms had been presented with reference to a short extra-high voltage (EHV) double-circuit cross-bonded (CB) underground cable (UGC) system. Since the cable link was short, the shunt reactive compensation was not used and consequently not considered. In this paper the procedure is generalized in order to take into account three single-phase (or also one three-phase) reactors installed at the cable ends or also at intermediate locations
Steady State Assessment of Shunt Compensated EHV Insulated Cables by Means of Multiconductor Cell Analysis (MCA)
Full text linkThe author has already presented some papers which allow studying cable systems by means of the multiconductor cell analysis (MCA). This method considers the cable system in its real asymmetry without simplified and approximated hypotheses. The multiconductor matrix procedure based on the use of admittance matrices, which account for the line cells (with earth return currents), different types of screen bonding, possible multiple circuits (single and double circuit or more), allows predicting the steady-state regime of any cable system. In the previous papers, these matrix algorithms have been presented with reference to a short extra-high voltage (EHV) double-circuit cross-bonded (CB) underground cable (UGC) system. Since the cable link was short, the shunt reactive compensation was not necessary and consequently not considered. In this paper the procedure is generalized in order to take into account three single-phase (or also one three-phase) reactors installed at the cable ends or also at intermediate locations
Brochure Cigré # 639: Cavi versus elettrodotti blindati
No full textLa brochure aveva il compito precipuo di fornire degli elementi per guidare la scelta tra un cavo e un elettrodotto blindato successivamente alla decisione di non costruire una linea aerea. I terms of reference, che sono le linee d'azione del WG che non si possono né eludere né valicare, asserivano che la finalità della ricerca non era quella di presentare i costi assoluti delle due tecnologie ma solo i costi relativi. In quest'ambito la brochure tecnica ha affrontato i seguenti argomenti:
• parametri economici nelle installazioni di cavi ed elettrodotti blindati e struttura dei costi relativi;
• confronto di tipiche installazioni interrate, in tunnel e in infrastrutture condivise;
• impatto ambientale in termini di sicurezza e campi magnetici esterni generati dagli elettrodotti in cavo e blindati;
• fattori di costo al fine di rendere le soluzioni comparabili e in modo particolare configurazioni del sistema, fasce di rispetto, aspetti di sicurezza, comportamento al fuoco, perdite elettriche nella trasmissione, necessità della compensazione reattiva derivata, invecchiamento delle apparecchiature, esperienza di esercizio, tenuta al gas in pressione (per GIL), riciclo dei materiali a fine vita, costi d'esercizio e manutenzione (O&M).
Inoltre, la brochure ha limitato il suo studio a:
- la trasmissione dell'energia elettrica in corrente alternata (la tematica HVDC era quindi esclusa);
- tensioni nominali comprese tra 52 kV e 800 kV;
- GIL e cavi ad isolamento estruso (i cavi superconduttori erano quindi esclusi)
Multiconductor Analysis of Underground Power Transmission Systems: EHV AC Cables
No full textIt is widely ascertained that the multiconductor analysis is a powerful tool that allows solving any circuit as far as structurally complex (e.g. high-speed railway supply system, gas-insulated lines etc.). Moreover, this method can be also used as an in-depth analysis of the electric networks after the power-flow studies when they introduce simplifying hypotheses especially in presence of asymmetry. In this paper, the multiconductor cell analysis has been applied to AC underground cable lines (UGC). This multiconductor procedure based on the use of admittance matrices, which account for the line cells (with earth return currents), different types of sheath bonding, possible multiple circuits, allows predicting the steady-state regime of any cable system. The method calculates the proportion and behaviour of the phase currents carried by each parallel conductor, the circulating current in the sheath of each cable and the stray current in the earth. Moreover, some comparisons have been made with traditional programs showing the great accuracy of multiconductor cell model
Esercizi di sistemi elettrici per l'energia
No full textTrattasi di libro di esercizi si sistemi elettrici per l'energia.
Un siffatto libro è molto importante per molti corsi del raggruppamento sistemi elettrici per l'energia
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