Alleviating bottlenecks in power interconnectors by means of FACTS

Power interconnections are becoming increasingly important in various parts of the world, as incentives for power exchange between countries are growing. A current example is the Baltic Energy Market Interconnection Plan launched by the European Council. For a variety of reasons, it is desirable to keep transmission corridors as slender as possible, i.e. keeping the number of lines as limited as possible, while still keeping adequate stability and power transmission capacity over the corridor. This is true, no matter whether it concerns a green-field project, or if it is a question of expanding an existing transmission corridor into higher power transmission capability. To achieve this, FACTS (Flexible AC Transmission Systems), based on state of the art high power electronics, is a highly useful option, from technical, economical and environmental points of view, to increase the utilization and stability of a transmission system or intertie. The paper presents salient design features as well as benefits of recently installed FACTS devices, more specifically SVC and series capacitors, for enabling or improving cross-border as well as interregional power transfer in a cost-effective and environmentally friendly way.