A centralized wide area control of facts for damping power system inter-area oscillations

Flexible AC Transmission Systems (FACTS) control for damping power system inter-area oscillations is a topic of much interest. However, local decentralized FACTS controllers are either too complicated to be realizable or do not offer satisfactory performance under various system operating conditions. This research develops a procedure for designing a centralized Wide Area Controller (WAC) for FACTS based on the Hinfinity method.;The Hinfinity control can guarantee robust performance by minimizing the effect of certain disturbances on the inter-area oscillations. This dissertation presents a new disturbance selection method under the Hinfinity method. A transformation of the disturbance vector is derived based on the response magnitude of the inter-area modes, which significantly reduces the number of disturbances to be rejected by the controller and decreases the computational time and memory for large power systems. The proposed method is applied to the IEEE 16-machine 5-area study system with multiple FACTS devices. Time delay of both the Wide Area Measurement (WAM) system and the FACTS control signals is considered. Power System Analysis Toolbox (PSAT) and MATLAB are used to design the controller and validate the results. The results demonstrate the effectiveness of the proposed method in design of FCATS Hinfinity - WAC for large power systems.