Here are the technical details of the NIE (Northern Ireland Electricity) to SP (Scottish Power) Interconnector. It ties Northern Ireland into the UK grid using a DC subsea cable:
The interconnection between NIE and SP is carried out using direct current(DC). There are two circuits connecting the two power systems and these are submarine cables approximately XX miles in length.
The cables operate at 250kV DC as two monopolar HVDC transmission systems rated at 250MW per pole, thus providing 500MW transfer capability. The HVDC converter stations are located at Ballycronan More (on Islandmagee in Northern Ireland) and at Auchencrosh (near Ballintrae in Scotland). These converter stations convert the electricity from AC to DC for transmission along the cable and then back to AC again. Power can flow in either direction.
There are two unique features to the equipment involved:-
i) The converter stations are the first in the world designed to use light triggered thyristors(LTT technology). With this technology the thyristors are not triggered by an electrical signal but by a pulse of light – this should make the process more reliable.
ii) The submarine cable design is also a world wide first in HVDC technology as the cables used have a coaxial construction i.e. a metallic ‘return’ conductor is provided as part of one cable.
The link is currently contracted to provide 125MW of power to NI as replacement for NI generation. The rest of the available link capacity (275MW) has been auctioned to energy traders in Ireland.
There are 2 larger interconnectors scheduled to go ahead fairly soon linking the Republic of Ireland to Wales.
"The East-West Interconnector Project"
The exact capacity of the system is yet to be revealed as it's still in the final stages of planning.
total cable length 130km. Also HVDC.
Last edited by djk; 03/25/07 08:43 AM.
