420 kV GAS INSULATED SWITCHGEARS & GAS INSULATED DUS DUCTS

摘要

Execution of underground 420 kV SF_S Gas Insulated Switchgears & Gas Insulated Bus ducts has been got done on turnkey basis from M/s SIEMENS AG Germany. The article deals with the various aspects of 420 kV SF_6 Gas Insulated Switchgears & Gas Insulated Bus ducts system, highlighting the salient features of equipment & installation. The underground powerhouse of Tehri H.P.P. Stage-1 accomodates four nos., 250 MW Generating units coupled to Vertical Francis turbines working under a net rated head of 188 m a long with its Mechanical electrical Auxiliaries. Out of eight nos. of 15.75/420 kV, three phase, 306 MVA Generator Transformers at El 605 m, four nos. of transformers meant for Tehri HPP Stage-l has already been installed and provision of four numbers of Generator Transformers for future Pumped Storage Plant (PSP) has been kept in the same cavern.