International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy, the regulatory authority for electricity and gas requires distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing 'reinforcement groundings' along the LV neutral conductor path and at users' delivery cabinet. Moreover, in urban high-load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, through neutral conductors, an effective connection between grounding systems of MV/LV substations, modifying Global Earthing System consistency. The aim of this paper is to evaluate the effect, in terms of electrical safety, of the aforementioned LV neutral distribution scheme when an MV-side fault to ground occurs. For this purpose, simulations are carried out on a realistic urban test case and suitable evaluation indexes are proposed.
Influence of LV Neutral Grounding on Global Earthing Systems / Cafaro, G.; Montegiglio, P.; Torelli, F.; Barresi, A.; Colella, P.; De Simone, A.; DI Silvestre, Ml.; Martirano, L.; Morozova, Er.; Napoli, R.; Parise, G.; Parise, L.; Pons, E.; Sanseverino, Er.; Tommasini, R.; Tummolillo, F.; Valtorta, G.; Zizzo, G.. - In: IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS. - ISSN 0093-9994. - STAMPA. - 53:1(2017), pp. 22-31. [10.1109/TIA.2016.2608325]
Influence of LV Neutral Grounding on Global Earthing Systems
Cafaro, G.;Montegiglio, P.;Torelli, F.;
2017-01-01
Abstract
International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy, the regulatory authority for electricity and gas requires distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing 'reinforcement groundings' along the LV neutral conductor path and at users' delivery cabinet. Moreover, in urban high-load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, through neutral conductors, an effective connection between grounding systems of MV/LV substations, modifying Global Earthing System consistency. The aim of this paper is to evaluate the effect, in terms of electrical safety, of the aforementioned LV neutral distribution scheme when an MV-side fault to ground occurs. For this purpose, simulations are carried out on a realistic urban test case and suitable evaluation indexes are proposed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
