Power system stability improvement by energy storage type STATCOM

This paper describes an approach to design a damping controller of an energy storage type STATCOM. The energy storage type STATCOM (ESTATCOM) is an advanced flexible AC transmission system (FACTS) device, which controls both reactive and active power injection/absorption to the power system. It also provides a better power swing damping. Using a linearized block diagram proposed by the authors, the present study examines the design of the ESTATCOM damping controller. Several case studies have been performed to evaluate the power swing damping effect of the ESTATCOM on one-machine infinite bus system. The results of the study show that an ESTATCOM, which controls both reactive and active power injection/absorption to power system, has a more significant effect on power swing damping than that controlling the reactive power alone.