26-12-2012, 01:02 PM
TYPICAL HVDC APPLICATIONS
1TYPICAL HVDC.docx (Size: 15.66 KB / Downloads: 26)
Advantages of HVDC over AC transmission
The advantage of HVDC is the ability to transmit large amounts of power over long distances with lower capital costs and with lower losses than AC. Depending on voltage level and construction details, losses are quoted as about 3% per 1,000 km.[16] High-voltage direct current transmission allows efficient use of energy sources, remote from load centers.
In a number of applications HVDC is more effective than AC transmission. Examples include:
• Undersea cables (e.g., 250 km Baltic Cable between Sweden and Germany,[17] the 600 km NorNed cable between Norway and the Netherlands, and 290 km Basslink between the Australian mainland and Tasmania[18])
• Endpoint-to-endpoint long-haul bulk power transmission without intermediate 'taps', for example, in remote areas, usually to connect a remote generating plant to the main grid, for example the Nelson River DC Transmission System
• Increasing the capacity of an existing power grid in situations where additional wires are difficult or expensive to install
• Power transmission and stabilization between unsynchronised AC distribution systems, for example between different countries that use AC at differing frequencies
• Stabilizing a predominantly AC power-grid, without increasing prospective short circuit current
• Reducing line cost. HVDC needs fewer conductors as there is no need to support multiple phases. Also, thinner conductors can be used since HVDC does not suffer from the skin effect
• Facilitate power transmission * Synchronize AC produced by renewable energy sources