FACTS devices and energy storage in unit commitment

Both Flexible AC Transmission System (FACTS) devices and energy storage may provide benefits to the power system, e.g. reduced transmission losses, improved system stability, voltage regulation and reduced congestion. As a result, FACTS devices can diminish the value of the installed energy storage and vice versa. In order to assess their impact on each other, this paper formulates a unit commitment model that includes generic energy storage and FACTS devices in order to investigate characteristics of their joint operation assess how they cancel out each other's benefits. The results of four unit commitment models are presented: (i) with no storage or FACTS devices (base case); (ii) with FACTS devices only; (iii) with energy storage only; (iv) with both FACTS devices and energy storage. An analysis of the benefits of both technologies is performed and economic assessment is presented. The simulations are performed on IEEE RTS96 system using CPLEX 12 under GAMS.