ABB Review Special Report - ABB - ABB Group

FACTSImproving the performanceof electrical gridsRolf Grünbaum, Åke Petersson, Björn ThorvaldssonAfter years of underinvestment in their transmission infrastructure, power utilities are being forced tolook at ways of utilizing their existing transmission lines more efficiently, at possibilities for cross-bordercooperation, and at the issue of power quality. This situation has dramatically increased interest in newas well as traditional solutions.FACTS (Flexible AC Transmission Systems), such as SVC, SVC Light ® , TCSC and others, are just suchsolutions. They take advantage of the considerable technical progress made in the last decade andrepresent the latest state of the art. While a typical application would be to increase the capacity of anygiven transmission line, this article describes some special cases with unique requirements and howthey were met.If prestigious projects were ever neededto demonstrate FACTS’ credentialsas an improver of T&D performance,none could serve better than the Dafang500-kV series capacitors helping to safeguardBeijing’s power supply, the EaglePass back-to-back tie straddling theUS/Mexican border, or the ChannelTunnel rail link. These, in their differentways, show why FACTS is arousing somuch interest in the electrical supplyindustry today.Dafang: series capacitors safeguardthe Beijing area power supplyPower demand in the area served by theNorth China Power Network, with 140million people and including Beijing, isgrowing at a steady pace. Installing newgeneration plant and transmission lines isnearly impossible due to urban growth.An attractive alternative is to insert seriescapacitors in the existing transmissioncorridor to provide series compensation.Special ReportABB Review13