Control frame for synchronous stability of interconnected power systems in deregulated environments

Power system restructuring brings about new challenges to power system stability, especially the transient stability (TS) and small-signal stability (SS) of interconnected large-scale power systems under large and cascaded disturbances. This is because of the need to yield more economic benefits in deregulated environments. In order to improve interconnected power system TS and SS in deregulated environments, the development of an effective global control frame is very important. In this paper a preliminary study on the issue is presented. First, nonlinear robust adaptive control (RAC) is applied to excitation system utilizing local measurements. Then, RAC for the supplementary control of HVDC transmission and FACTS device (e.g. TCSC) using the WAMS signal of system center of inertia (COI) dynamics is presented. The computer test results are shown to be very positive. Based on the results, an overall control frame is suggested for enhancing TS and SS of interconnected power systems. Future work in realizing the new control frame is also discussed