DC links carry bulk power over long distances with low losses.
HVDC converters (LCC thyristor or VSC IGBT) link grids and move bulk power with lower losses and no reactive power on lines; cheaper for >600 km overhead or >50 km submarine. Allows asynchronous interconnection and offshore wind connections.
A ±800 kV link can move 8 GW over 2000 km.
HVDC links carry large amounts of power over long distances or between grids with different frequencies, with lower losses than AC cables.
DC links carry bulk power over long distances with low losses.
HVDC links carry large amounts of power over long distances or between grids with different frequencies, with lower losses than AC cables.
Cable charging current is a major issue for long AC cables, but DC does not have that effect in steady state, so losses are lower.
They convert between AC and DC at each end, usually using thyristor or IGBT-based converters.
Typical applications include connecting an offshore wind farm to the onshore grid with a submarine cable, linking two grids that operate at different frequencies and transmitting bulk power across a long overland route with minimal losses.
Study "Reactive power and voltage control" first (topic 78 of 106 in Electrical Engineering). It covers the groundwork this topic builds on.
No stability limit with distance. Converter stations are costly. Multi-terminal grids emerging.
A ±800 kV link can move 8 GW over 2000 km.
The next topic is "Renewable integration", which builds directly on this one.
It is classed as Advanced in Electrical Engineering (topic 79 of 106). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Electrical Engineering.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.