计及量测噪声的特征节点对联合判稳与紧急控制

Fast identification of transient power angle stability and implementation of emergency control have important significance in reducing the risk of instability and ensure the safety of power grid. For the two nodes at different locations, the temporal and spatial distribution of phase difference and frequency difference between node voltage phasors and the intrinsic correlation characteristics of the phase-frequency trajectory between the generator pair and node pairs were analyzed. The influence of wide area measurement system (WAMS) signal-to-noise ratio (SNR), the time window of fitting and the cut-off frequency of filters on the identification delay and mis-identification rate of concavity and convexity of phase-frequency trajectory were evaluated, and the tuning method of sampling and filtering parameters were proposed. In order to adapt to the influence of non-coherent oscillation of generators on the concave and convex stability identification of node pairs, a joint stability identification method and an emergency control strategy based on the trajectory’s concavity and convexity of characteristic node pairs including the key branch node pair NP_kb and the node pair with maximum phase NP_m were proposed. The simulation results from AC/DC hybrid power grid verify the correctness of the parameters’ tuning method and the effectiveness of the proposed stability identification method and control strategy.