HVDC troll
The HVDC Troll is a high-voltage direct current transmission between the Norwegian gas processing plant Kollsnes and the Sea Troll oil rig operated by Equinor . It is the first application in which an offshore drilling platform is supplied with an HVDC transmission from land.
Location of the two converter stations |
Troll A 1 & 2
The plant was built by Asea Brown Boveri (ABB). As for the first time at the HVDC Visby-Näs 1999 HVDC Visby-Näs , the dual-bipolar variant HVDC Light from ABB, with water-cooled IGBTs (2.5 kV / 500 A) as the controlling electronic element, was used. The establishment contract was concluded in 2002. The installation was completed in 2004, and the electrical tests were completed in February 2005. The entire complex has been fully operational since October 1, 2005.
The transmission has a length of 70 km. With an operating voltage of ± 60 kV, an electrical power of 88 MW is transmitted. A triple-extruded polymer submarine cable is used as the transmission medium , which is voltage- resistant up to 150 kV and has a cross-section of 300 mm². The maximum laying depth is 350 m. The infeed in Kollsnes is made by transformers of 56 MVA each with a static rectifier . The supply voltage is 132 kV and the extraction voltage on the drilling platform 56 kV. The system is used to supply energy to two natural gas compressors, which are driven by high-voltage synchronous motors with an operating voltage of 56 kV and an output of 44 MW, on the drilling rig. There is no need for a transformer on the oil rig.
Troll A 3 & 4
It is planned to put another HVDC (Troll A 3 & 4) into operation by 2015 [obsolete] with a transmission capacity of 100 MW and an operating voltage of 66 kV.