Critical lines identification and mitigation strategy for wind-integrated power systems under N-k contingencies

The frequency of N-k contingencies increases with the growing integration of renewable energy sources such as wind power. During an N-k contingency in wind-integrated power systems, component outages can lead to large-scale power flow transfer. Additionally, the transfer will be aggravated by the intense fluctuation of wind power and the hidden failures of the relay protection device, potentially causing cascading failures. Thereby, accurately identifying critical lines and adopting mitigation strategies hold profound significance in reducing the scale of cascading failures. In this study, a critical lines identification algorithm and its mitigation strategy based on saturated cut-set for wind-integrated power systems are proposed, aiming to alleviate the persistent impact of wind power uncertainty under N-K contingencies. The evaluation using the IEEE 118-bus system illustrates that the critical line identification algorithm integrating mitigation strategy achieves accurate identification results. Furthermore, the proposed algorithm is validated through MATCASC cascading failure verification, and its performance is compared with that of other algorithms. The simulation results indicate that the proposed method effectively reduces the workload for operational maintenance of critical lines, thereby enhancing situational awareness capabilities.