Interaction Studies between Sofia & Dogger Bank C Offshore Wind Farms

The Sofia and Dogger Bank C offshore wind farm projects both connect to the National Grid Lackenby substation at 400kV voltage level via VSC-HVDC connections. The projects plan to connect wind power capacity of circa 2.5 GW.

The Sofia transmission system consists of a 1320MW VSC-HVDC symmetrical monopole ±320kV transmission system with a 220km export cable, designed and built by GE Vernova. The offshore network is at 66kV connecting x100 Siemens Gamesa 14MW wind turbines. The onshore substation is connected to the NGET Lackenby substation by a 2km 400kV cable.

The Dogger Bank C transmission system consist of a 1200MW VSC-HVDC symmetrical monopole ±320kV transmission system with a 272 km export cable, designed and built by Hitachi Energy. The offshore network is at 66kV connecting x100 GE Haliade 14MW wind turbines. The onshore substation is connected to the NGET Lackenby substation by a 2km 400kV cable.

Connection to the UK grid and completion of the overall project are both targeted for 2026.

Services provided

• Facilitating interaction studies, that study the interaction phenomena that may exist between the Sofia and Dogger Bank-C HVDC converter systems.
• Provide and coordinate an impartial advisory service to all stakeholders in the deployment of mitigation actions.
• Protect the intellectual property of HVDC and WTG manufacturers.