Experience with Construction of 500 kV Gas Insulated Switchgear at the Votkinsk Hydroelectric Power Plant

The design documentation for reconstruction of the 500 kV outdoor distribution system was prepared for Votkinsk Hydroelectric Power Plant (HPP). The main structural and installation effort and the installation of power equipment and secondary switches took place from March 2013 through April 2014. Stepwise bringing of the new equipment into operation and removal of the of the existing equipment took place from April through October 2014. The reconstruction included construction of a building for the electrical apparatus for the GIS, together with the 500 kV relay cabinet, within which the equipment for the GIS, relay protection, emergency automation, automated electric power fiscal metering, automatic process controller, 380 V in house needs, and dc operational current panel. The Spanish firm Iberdrola, was responsible for the two-stage bargaining for completion of the design and development of working documentation, government review of the project, delivery of materials and equipment, construction-installation and adjustment work, and raising and matching of all questions with interested organizations. S.A.U. The obsolete equipment has been replaced by modern high-reliability indoor SF6 equipment. The location of the gas insulated switchgear building has made it possible to connect the apparatus to overhead transmission lines and transformer units using short outdoor SF6 current carriers instead of high-voltage cable inserts. The structural-installation work and comprehensive adjustment of the equipment are done without transfer of the existing 500 kV outdoor distribution equipment. The use of GIS equipment has substantially reduced the number of people in the areas with high electric fields during operational switching, repairing, and servicing of high-voltage equipment at the HPP.