Siemens converts Moscow to gas-insulated switching

Siemens Power Transmission and Distribution (PTD) is to replace a 40-year-old high-voltage outdoor switching station in Moscow city centre with space-saving gas-insulated switchgear (GIS).


By converting to gas-insulated technology, the Russian state-owned Federal Grid Company (FGC) aims to improve the reliability of the power supply, and it will be able to expand the power supply system in future to keep pace with the city’s growing energy requirements.


The order is valued at about €£53m and the first circuit-breakers are due to be switched in before the start of winter 2007. According to Siemens, the project will require good logistical management. Nine 500-kV switchgear bays, 32 220kV bays and six 110kV bays will have to be delivered in the centre of Moscow on schedule.


The gas-insulated switchgear will be installed on the same site next to the old air-insulated system. The use of GIS technology is said to be essential due to the restricted space available and to meet the required short installation times.

Since the 500kV switchgear bays have to operate within a restricted area, they are equipped with outgoing cable units that enable the existing overhead line feeders to be used via a cable run within the station site. Because an uninterrupted supply of power to the city must be guaranteed while the conversion is in progress, individual switchgear sections will only be disconnected from the power supply system for short periods while the work is being performed.