Study on power system extended small signal stability region (DE-SSSR) in time delay space

In power system, coordination controllers are usually designed based on the data from PMU and WAMS. Time delays in the measurement data are significant so that they can not be simply ignored. So, it is important to evaluate the impact of time delays on power system stability analysis and controller design. In this paper, an extended small signal stability region in time delay space (DE-SSSR) is presented so that it can consider the low frequency oscillation phenomena captured in the power system operations. Definition of DE-SSSR is first given, and the structure of its boundaries is discussed. Then a practical method is given to trace the boundaries of DE-SSSR. Finally, WSCC 3-generator-9-bus system is employed to validate the effectiveness of the presented method. Work of this paper is helpful to power system stability assessment and controller design with considering time delays in wide-area environment.