Siemens 's first gas-insulated switchgear for direct current transmission reduces costs of offshore windpower

Erlangen, Germany - Siemens presented the first compact gas-insulated switchgear (GIS) for high-voltage direct current applications.

Within the framework of the energy transition, high-voltage direct current (HVDC) transmission is gaining in significance as it allows low-loss transmission of large amounts of electricity over long distances. The new 320-kilovolt (kV) gas-insulated switchgear uses up to 95 percent less space compared to previous air-insulated units. When used on an offshore platform, the platform size can thus be decreased by approximately 10 percent.

The efficient HVDC transmission technology is necessary to bring wind power generated in the North Sea to load centers in southern Germany, for example. For this, 155 kV of alternating current (AC) from wind power is converted on a converter platform into 320 kV of low-loss direct current (DC) and then transmitted to land via submarine cables. When transmitting electricity, the general rule is that the higher the voltage, the less power lost. Once on land, a converter station converts the direct current back into alternating current for further distribution.

The direct current switchgear that is part of the converter station currently uses air-insulated technology and thus requires a large amount of space. Because of air

Source: IWR Online, 26 Aug 2014