Licence: Approval to introduce implicit loss handling on the Skagerrak Interconnector using a fixed annual loss factor
On 26 March 2019, transmission system operators Energinet and Statnett submitted a joint application to introduce implicit loss handling on the Skagerrak Interconnector, which consists of four parallel HVDC cables including Skagerrak 3, proposing implementation of a fixed annual loss factor based on historic median flows and presenting the methodology, rationale, and expected socio-economic effects for Norway and Denmark.
In 2015 Hitachi Energy completed a major upgrade of the Skagerrak 3 HVDC Classic pole’s control system (MACH), enabling the Skagerrak 3 link between Kristiansand (Norway) and Tjele (Denmark) to operate in a bipole configuration together with the new Skagerrak 4 HVDC Light link for Statnett and Energinet.dk.
In 2014 the Skagerrak system was reconfigured so that Skagerrak 3 began operating in a hybrid bipole together with Skagerrak 4, while Skagerrak 1 and 2 again formed a separate bipole. In this new arrangement SK3 (an LCC monopole) and SK4 (an asymmetric VSC monopole) share the same earth electrode, and although they have different power ratings and DC voltages, their similar rated DC currents result in low currents to ground.
Nexans was the selected supplier for the Skagerrak 3 subsea HVDC cable, delivering a third 350 kV submarine cable across the Skagerrak strait between Denmark’s Jutland peninsula and Norway in 1993, upgrading the interconnector with an additional 500 MW of transmission capacity.
In 1993, Nexans completed delivery and installation of the Skagerrak 3 350 kV HVDC subsea cable between Denmark and Norway, upgrading the Skagerrak interconnector with a third link that added 500 MW of transmission capacity alongside the existing Skagerrak 1 and 2 cables.
Skagerrak 3, a 350 kV HVDC monopole link between Kristiansand in southern Norway and Tjele in Denmark, was commissioned and became operational in 1993, adding roughly 500 MW of transmission capacity to the existing Skagerrak interconnector system owned by Statnett and Energinet. This third pole, using line-commutated converter technology, was integrated with the earlier Skagerrak 1 and 2 links to increase cross-border power exchange capability between the Norwegian hydro-based system and the Danish system, and has operated as part of the interconnector since that time.
| Norway | Denmark | |
|---|---|---|
| Landfall | Kristiansand, Norway | Tjele, Denmark |
| Grid Connection | Kristiansand HVDC Static Inverter (Kristiansand, NO2) | Tjele HVDC Static Inverter (Tjele, DK1) |
Norway
Denmark