Automatic Load Shedding Emergency Control Algorithm of Power System Based on Wide-Area Measurement Data

On the basis of direct method for power system frequency stability analysis, combining with wide-area measurement technology, an automatic load shedding control algorithm is proposed. In the proposed algorithm, it is not necessary to research the system parameters after the attenuation of transient process, the Jacobian matrix is calculated by directly using the wide-area measurement data at the instant after disturbance occurs, thus the steady state frequency of power system after the disturbance as well as the load shedding amount to make the steady state frequency keeping its setting value can be predicted. In the proposed algorithm the network loss variation during the disturbance and practical valve limits of prime motors is taken into account. By means of PSS/E software and WSCC 9-bus system, the simulation of the proposed algorithm is conducted. Simulation results prove that the proposed algorithm is correct.