Static Synchronous Compensator with Superconducting Magnetic Energy Storage for High Power Utility Applications

MOLINA, MARCELO GUSTAVO; MERCADO, PEDRO ENRIQUE; WATANABE, EDSON HIROKAZU

ENERGY CONSERVATION AND MANAGEMENT

Pergamon Press (Elsevier)

Lugar: Oxford; Año: 2007 vol. 48 p. 2316 - 2331

0196-8904

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). Because the generation is an electro-mechanical process, the primary control reserve controllability is not as fast as required, especially by modern power systems. Since new improvements achieved on the conventional control methods have not been enough to satisfy the high requirements established, the necessity of enhancing the performance of the PFC has arisen. At present, 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 possible to combine this new ESS with power converter-based Flexible AC Transmission Systems (FACTS). This allows an effective exchange of active power with the electric grid and thus enhancing the PFC. This paper presents an improved PFC scheme incorporating a Static Synchronous Compensator (STATCOM) coupled with a Superconducting Magnetic Energy Storage (SMES) device. A detailed full model and a control algorithm based on a decoupled current control strategy of the enhanced compensator are proposed. The integrated STATCOM/SMES controller topology includes three-level multi-pulse voltage source inverters (VSI) with phase control, and incorporates a two-quadrant three-level dc-dc chopper as interface between the STATCOM and the SMES coil. A novel three-level control scheme is proposed, by using concepts of instantaneous power in the synchronous-rotating d-q reference frame. The dynamic performance of the presented control algorithms is evaluated through digital simulation carried out by using SimPowerSystems of SIMULINK/MATLAB? and technical analysis is performed to obtain conclusions about the benefits of using SMES devices in the PFC of the electric system. Presently, a laboratory-scale prototype device based on digital signal processors (DSP) is being implemented.