Compact HVDC converter station design considerations

In this paper, the possible means to reduce HVDC converter station land area requirements are shown. The split-up of real estate between the different kinds of equipment in present-day terminals is analysed. From this, a priority list for suitable action to be taken is deducted. Three concepts of converter valves suitable for compact converter stations are briefly discussed. By example of a 2400 MW terminal it is shown that with air-insulated liquid cooled thyristor valves a land area requirement of 0.8 m²/MW (8.5 sq. ft./MW) can be achieved, i.e. 1. 2 % of that required by the Pacific Intertie. Alternative solutions with metalclad valves are introduced and it is concluded that for converter stations with high rating in metropolitan areas, air-insulated liquid cooled thyristor valves seem to be the most appropriate choice. Where a low profile station is desirable, dead tank oil-insulated thyristor valves for outdoor mounting could be the optimum solution.