An on-line transient stability emergency control strategy based on PMU forecasted trajectory

On-line emergency control strategy is proposed based on PMU data and forecasted trajectory in this paper. The rolling optimization in predictive control algorithm is established to predict the moving trajectory and Extended Equal Area Criterion (EEAC) is used to predict and analyze the degree of stability. Furthermore by analyzing the synchronization stability characteristic, a composite index which can reflect the unstable status and control effect is constructed to choose generator- shedding. The scheme is independent of the detail mathematical model and could restrain the mismatching for some unpredicted contingency and avoid the chain reaction leading to blackout. The proposed scheme is tested by a practical power grid and the results indicate its feasibility and effectiveness.