Assessing the technical value of FACTS-based wide-area damping control loops

Engineers intuit that, as power systems interconnect more and more to exchange large amounts of power over longer transmission lines, wide-area damping control should become increasingly rewarding. However, given the current technological and psychological barriers, decision makers need tools to assess whether the inherent advantages of wide-area control over local control can outweigh the risk incurred by the additional complexity of the underlying telecommunication and SCADA systems. This paper devises a simple small signal analysis-based methodology for pinpointing control sites where wide-area control has a substantial technical advantage over a purely local control. Using a novel fuzzy logic-based PSS scheme applicable to both static var compensators (SVC) and synchronous condensers (SC), the authors first demonstrate the claims of their paper on an interesting three-area power system proposed by Anderson and Farmer. Based on small- and large-signal studies, the findings are then generalized to a large study network from Quebec´s provincial ISO, equipped with SVCs and SCs at six and four 735-kV substations respectively, all of them included in the scope of this study. Overall, wide-area control is consistently three to 20 times more efficient technically than the competing local control, depending on the network and the control site.