Abstract: The phase and time information of a voltage at a power supply outlet is detected at points, and sent to a data server. With one end of a system used as a phase angle reference, the data server observes phase differences at another end, and at a center. The data server then extracts an inter-system fluctuation component from an obtained fluctuation, and constructs an expanded combined vibration model for data sets obtained through first- and second-order differentiations of the component. The expanded combined vibration model is obtained by expanding a combined vibration model to include a known model of a PSS provided for a generator of interest. Time-series data regarding state variables of the PSS at the time of construction of the expanded combined vibration model are obtained, and PSS parameters are determined directly therefrom by the expanded combined vibration model, thereby achieving stabilization of dominant modes.

Abstract: In the present invention, at each of the plurality of points in a wide area, the phase of voltage at a power supply outlet is detected. Data including the phase information and time information are sent to a data server. With one end of the system used as a phase angle reference, the data server observes phase differences at the other end and at the center of the system. The data server then extracts an inter-system fluctuation component from an obtained fluctuation, and constructs an expanded combined vibration model for data sets obtained through first-order and second-order differentiations of the component. The expanded combined vibration model is obtained by expanding a combined vibration model to include a known model of a PSS provided for a generator of interest.