An adaptive emergency control method for interconnected power grids against frequency decline and system blackout

The occurrence of a large disturbance in a power system can lead to a decline in the system frequency due to a real power deficiency or generation-load imbalance. The emergency control action is required to stop the system degradation immediately and minimize the impact to the system. In this paper, an adaptive emergency control method is proposed to prevent the system excess frequency decline and even the large blackout. It consists of two main stages. In the first stage, the real-time triggering criterion deciding whether to trigger the adaptive control is presented by predicting the frequency excursion. The second stage aims to designing an optimal emergency control strategy, which eliminates the imbalance power whilst minimizing the control cost. The strategy cannot be limited by the traditional offline control strategy table. The effectiveness of the proposed emergency control method is demonstrated via numerical example on the inter-connected power grid of the North Grid of China and the Central Grid of China. The proposed method can be executed in a simple and efficient way because the complex transient time-domain simulations of large-scale power system can be avoided.