Perturbed Trajectory Prediction Method based on Simplified Power System Model

With the interconnection of power grid, the post-disturbance system is easier to suffer power-angle swing and system oscillation. Moreover, the impact of load characteristics on the system dynamic behavior becomes more obvious. Therefore a new perturbed trajectory prediction method considering load model is presented in this paper. A static load model with voltage characteristics instead of pure impedance is introduced into the system models. The admittance matrix including load nodes and a coefficient matrix of load proportion are figured out based on the real-time data from WAMS (wide-area measurement system). Using the sensitivity equation of power flow, the linear relationship between the micro variation of electromagnetic power and that of rotor angle is deduced, and then a new perturbed trajectory prediction algorithm is proposed. Numerical simulation results on the IEEE-9 bus system show that the proposed method works well