An Online Transient Stability Control Strategy Based on Post-Disturbance Equilibrium Point Continuation: Calculation of Post-Disturbance Equilibrium Points

To address the limitations of traditional power flow models in calculating post-disturbance equilibrium points in power systems, a method for calculating post-disturbance system equilibrium points that accounts for the steady-state operating characteristics of dynamic components is proposed. First, from the perspective of algebraic equations, an analytical model for post-disturbance equilibrium points is constructed, incorporating power sources, loads, and the network. Subsequently, based on the homotopy method, an efficient solution procedure for post-disturbance system equilibrium points is presented, resolving the convergence challenges of the Newton method under severe disturbances. Finally, the proposed method is validated using the IEEE 39-bus standard test case and a provincial real-world grid case. The results demonstrate that the developed model is applicable to dynamic components, including renewable energy sources, exhibiting strong generality. The proposed calculation method yields results fully consistent with transient simulation outcomes while reducing convergence time by over 95%. Compared to traditional power flow methods, its accuracy is improved by at least three orders of magnitude, providing an efficient analytical tool for rapid online stability assessment of post-disturbance systems.