An efficient index to deal with interaction phenomena of FACTS devices in power systems

In this paper, an original sensitivity index has been developed in order to evaluate, before the insertion of a STATCOM (STATic COMpensator) the interaction phenomena severity resulting from this insertion in a two-area four-machine test power system. The study has been carried out using small signal stability theory and eigenvalue analysis. This index, derived from the controllability and observability factors, can be calculated for each oscillation mode. The index has been tested on the poorly damped inter-area mode of the test system for three different configurations: the test system alone, the test system with a STATCOM in operation and the test system with a generator equipped with a PSS (power system stabilizer). Results have shown that, in all of these configurations, the index permits the selection of the location of the STATCOM in order to limit the interaction phenomena on the inter-area oscillation mode.