Doc No: 9AKK100580A1999
Title: HVDC - A firewall against disturbances in high-voltage grids.pdf
Revision: -
File type: pdf
Summary: extract from ABB Review 03/2005, by Lennart Carlsson
Cover page:

Doc No: 9AKK100580A1999
Title: 42-46 HVDC - A "firewall" against disturbances in high-voltage grids
Revision: -
File type: pdf
Summary: Interconnections between grids are desirable because they not only permit economies through the sharing of reserves, but they also make the trading of electricity between grids possible. On the downside, however, disturbances can easily spread from one area to another. Major blackouts in recent years have shown how relatively minor malfunctions can have repercussions over wider areas. As one link overloads it is tripped, increasing the strain on neighboring links which in turn disconnect, cascading blackouts over vast areas and causing huge productivity losses for the economy. The solution is a “firewall” permitting the interchange of power but preventing the spread of disturbances. This can be accomplished using high voltage DC (HVDC) connections. A HVDC link can fully control transmission but does not overload or propagate fault currents.