The main feature of this system is that the electrical power cable is protected within a steel riser pipe.
One of the main problems experienced by the offshore wind industry is failure of electrical cables and connectors during installation and operation.
There is a risk that the dynamic cable between the seabed and the floating structure could also suffer damage.
By installing the cable within the riser pipe then it will be protected at all times. The pipe will also be filled with inhibitor fluids for additional protection.
The riser pipe will be supported by mooring chains and buoyancy in a hybrid single line assembly. Hybrid Single Line Mooring Brochure.
When not in use, the hybrid mooring line termination pullhead would float at a position 20 – 30 m below the surface.
The floating structure would then be towed to the field and positioned above the termination pullhead. The pullhead would then be pulled upwards into the mooring turret by a single winch and then be mechanically locked into the turret. The electrical power transmission cables would then be connected.
In order to enable the high electrical power generated to be transferred from the wind turbine to the dynamic umbilical, the power cable is allowed to spiral rotate within the steel riser. This avoids the requirement to use a slip ring and provides a continuous cable transmission system.