Comparative evaluation of performance of a STATCOM and SSSC both integrated with SMES for controlling the power system frequency

Power systems security in case of contingencies is ensured by maintaining adequate "short-term generation reserve". This reserve must be appropriately activated by means of the primary frequency control (PFC). Nowadays, the new energy storage systems (ESS) are a feasible alternative to store exceeding energy for substituting the primary control reserve. In this way, it is feasible to combine this new ESS with power converter-based FACTS controllers. This allows an effective exchange of active power with the electric grid and thus enhancing the PFC. The current article presents the detailed models of power converter-based FACTS controllers with shunt and series connection to the utility system, i.e. static synchronous compensators (STATCOMs) and static synchronous series compensators (SSSCs), both combined with SMES coils. Moreover, a three-level control scheme for these integrated systems is proposed and a comparative evaluation of performance of both controllers in the PFC is carried out.