HVDC Light™

The world’s first HVDC Light™ offshore converter

Cable data Project features

Voltage +/- 80 kV DC HVDC Light Cable and AccessoriesPower 2 x 40 MW Cable System designRoute length 68 km Project ManagementConductor 300 mm2 Cu Submarine InstallationWater depth 350 m Onshore InstallationCable length 4 x 68 km = 272 kmWeight 15 kg/mCustomer Statoil SF, NorwayYear 2004

Unique and efficientcombination of power

transmission andfrequency regulated

electric drives

Troll A platform, North Sea

BU CablesTelephone Telefax E-mail

ABB Power Technologies AB +46 455 556 00 +46 455 556 55 sehvc@se.abb.comwww.abb.com/cables

SEHVC M-062E

1st order for HVDC Light™technology for sustainabledevelopment in the offshore market

ABB has designed and built two 68-kilometre submarine high-voltagepower feeders to the Troll A gasproduction platform at the continentalshelf in the North Sea west of Norway.Using ABB’s HVDC Light™technology, the Powerformers®(motors with cable wound extra highvoltage windings), driving thecompressors, is fed from environmentalfriendly produced power from shoreenable the offshore industry to meettheir goals towards sustainabledevelopment.

Government-owned Statoil ASArepresenting the Troll Group placed theorder. The Troll Group comprises ofStatoil ASA, Petoro AS, Norsk HydroProduksjon a.s, A/S Norske Shell,TotalFinaElf Exploration Norge ASand ConocoPhillips Norge.

ABB has provided a complete HVDCLight transmission system, made up ofhigh-tech extruded cables buried in theground and seabed, with a converterstation at the onshore and offshoreends of the feeders. The onshorestation converts 132 kV AC-voltage to+60 kV DC-voltage and transmit 2 x 40MW power to the offshore stationwhere the DC-voltage is converted to56 kV AC-voltage. The offshore stationacts as inverters in electricPowerformer® (motor) drive systemsfor compressors which boost gaspressure to maintain gas deliveryoutput. The offshore converterregulates the frequency and voltage inorder to achieve smooth start and avariable speed of the Powerformerbetween 3570 and 5355 rpm.This unique combination of efficientand environmental friendlytransmission solution over long distanceand features for controlling electricmotor drives as well as the uniquedurable DC-cable design for toughinstallation conditions, secured this firstorder for HVDC Light™ technology tothe offshore industry.

HVDC Light™ technologyHVDC Light™ is a concept of moderntechnology based on bi-polar convertersand extruded DC cables with power unitsup to 350 MW. HVDC Light™ convertersgive high-speed control of active andreactive power in both the AC and DCnetworks. HVDC Light Cable is a cablewith extruded polymer insulation andspecifically adapted for direct voltage. Thestrength and flexibility of HVDC LightCables makes them well suited for severeinstallation conditions both as anunderground land cable and as a submarinecable. HVDC Light™ therefore providesthe ideal medium for transmitting powerover any distance underground or underthe sea.

HVDC Light Cable qualificationThe HVDC Light polymeric cable system isat present (2004) qualified up to 150 kV(Um=165 kV). The qualification testscomprised of successful Long Term andType testing. As of December 2003, 1342km of HVDC Light Cable has beendelivered, including Troll A and theprojects at Gotland in Sweden, Tjaereborgin Denmark, Directlink and Murray Link inAustralia and Cross Sound - Long island toConnecticut - in the United States ofAmerica.

New applications with polymericHVDC Light CablesCompared with traditional paperinsulated cable, the polymeric cable hasa number of advantages due to itsexcellent mechanical strength andflexibility. These advantages allow theuse in areas of;� Steeps (e.g. offshore platform

risers)� Extreme water depths� Tough installation conditions� Dynamic movements (vibrations)

Installation at the Troll A platformThe submarine HVDC Light cables forthe two 40 MW drives consists of 4nos. of single conductor cables. All areinstalled in the same 423 m long J-tubefrom just above the sea bottom at 300m water depth to level 30 m above thesea level on the platform. The cables,loaded on the cable laying vessel, werepulled simultaneously in through the J-tube, hung-off at top and sealed off atboth top and bottom of the J-tube. TheJ-tube was then filled with an inhibitorfluid to prevent corrosion. In order tolimit the pull break force in case offishing trolleys or boat anchors hookingon to the cable package, the hang-off isequipped with a weak link disrupting at250 kN.

The remaining installation wasperformed by conventional submarineand land installation methods.

Low magnetic fields from HVDCLight CablesThe HVDC Light Cable System has theadvantage, due to its bi-polarconstruction, of virtually eliminatingmagnetic radiation generated from thecurrent in the conductors. This featureis of great importance for obtainingrequired permits from environmentalagencies.