High voltage direct current transmission system
A consortium of GE Renewable Energy’s Grid Solutions and Sembcorp Marine will supply Sofia's high voltage direct current transmission system. The system will include two HVDC converter stations - one offshore and one onshore - with innovative converter modules and a new high-tech control system deployed. The offshore converter station will be the most powerful ever fabricated, and the farthest from shore.
The system will utilise GE Grid's second-generation voltage source convertor valve and feature the first application of its state-of-the-art eLumina™ HVDC Control System. eLumina is the industry’s first HVDC solution to use a digital measurement system fully based on International Electrotechnical Commission (IEC) 61850, an important international standard defining communication protocols for intelligent electronic devices at electrical substations.
The offshore converter platform will be the heart of the wind farm and will comprise a 17,000 tonne topside attached to a jacket foundation piled into the seabed. The onshore converter station will convert the electricity generated by the wind farm to 400 kV, before it enters the national grid.