Power System Dynamic Stability Analysis and Stability Type Discrimination

In the static voltage stability analysis, the singular point of the power flow Jacobian is usually considered as the critical point. As this method does not take the dynamics of the components into account, the creditability of the results obtained are more or less affected. Based on the continuation algorithm, this paper investigates the dynamic stability using the small signal analysis method. The stability mode of power system can be distinguished by the modal participation factors of the state variables. Firstly, the equilibrium manifold is traced by a locally parameterized continuation method. Then, the dynamic stability of each equilibrium point is analyzed using the small disturbance analysis method considering the dynamics of the generators, the excitation system, the governor and the SVC. The system state matrix is calculated numerically by applying small perturbation to each state in turn. Simulation results show remarkable differences in the stability critical points obtained by the small signal perturbation dynamic analysis and the static analysis. Also a region of dynamic voltage stability is found in the lower portion of the PV curve.