Gotland HVDC Light map with converter stations Näs and Bäcks.
Gotland HVDC Light
Gotland HVDC Light - the world's first commercial HVDC transmission using VSC converters. An important reason for selecting HVDC Light was that great difficulties were experienced in getting the necessary permits to build an additional overhead transmission line.
The push for renewable forms of energy has brought wind power plants to southern Gotland, a Swedish island in the Baltic Sea. Southern Gotland already had a wind power capacity of 40 MW installed, and more capacity additions were in progress. This called for additional transmission capacity, as well as for better means to maintain a good power quality, as the variable operating conditions that wind power plants are subjected to result in flicker and in variations of reactive power.
Equally important, great difficulties were experienced in getting the necessary permits to build an additional overhead transmission line.
HVDC Light’s capabilities to overcome the power quality problems in wind power plants and that the transmission was to utilize underground cables, encouraged the local utility GEAB to decide to build the world’s first commercial HVDC Light transmission. GEAB is a subsidiary of Vattenfall AB, who financed the project together with the Swedish National Energy Administration.
The Näs HVDC Light
Laying of the two
HVDC Light cables
The transmission link between the southern part of Gotland and the city of Visby is rated 50 MW and was put into operation in June 1999. Two 70 km long extruded 80 kV HVDC Light underground cables, ploughed into ground close to each other, connect the stations. All equipment was mounted in enclosed modules in the factory and were fully factory tested, so that civil works, installation and commissioning was kept to a minimum.
Näs HVDC Light converter station, exterior view
|Power rating:||50 MW|
|No of circuits||1|
|AC Voltage:||80 kV (both ends)|
|DC Voltage:||±80 kV |
| Length of DC land cables:||2 x 70 km |
|Main reason for choosing HVDC Light:||Wind power (voltage support). |
Easy to get permission for underground cables.