Siemens has been awarded an order to supply a link between the French and British power grids. The customer is ElecLink Limited, a wholly owned subsidiary of Groupe Eurotunnel SE. The “ElecLink” high-voltage direct-current (HVDC) link will enhance power supply reliability in both countries and promote the integration of renewable energy sources into the power grid. Siemens will supply the two HVDC converter stations at both sides of the DC power line, which will be routed as a DC cable through the Channel Tunnel. This cable is to be supplied by Prysmian and installed by Balfour Beatty.
The volume of Siemens‘ share of the order is around EUR 315 million. The link is scheduled to take up commercial operation early 2020. The foundation stone of the future converter station was laid on Feb. 23, 2017, by Jesse Norman, Minister for Industry and Energy, signaling the start of the construction work that, when complete, will supply enough electricity to power more than 1.65 million typical households per year.
The HVDC link between France and Great Britain has been designated as one of the European Commission’s projects of common interest to help create an integrated European Union energy market. As the cable goes through the Channel Tunnel there will be no subsea lay or burial in the Channel.
The scope of the order covers a 1000 MW converter system for a DC voltage of ±320 Kilovolt (kV). The two converter stations, one at Peuplingues in France, the other in Folkestone in the UK, will be linked by a 51 kilometer-long DC power cable. The scope of supply includes the overall system design and the supply, installation and commissioning of all components. The HVDC power modules and HVDC transformers will be manufactured at two Siemens factories in Nuremberg, Germany.
Both converter stations will be using HVDC Plus voltage-sourced converters in a modular multilevel converter arrangement (VSC-MMC) that convert AC to DC and DC back to AC on the other side of the link. In contrast to line-commutated converter technology, the HVDC Plus system works with power transistors that can also be switched off (IGBT), enabling the commutation processes in the power converter to run independently of the grid voltage. The very fast control and protective intervention capabilities of the power converters provides a high level of stability in the transmission system, which primarily serves to reduce grid faults and disturbances in the three-phase AC network. This significantly increases supply reliability for utility companies and power customers.