A Grid Resilience Enhancement Approach Considering Cascading Failures due to Reduced Carrying Capacity Under Extreme ice Disasters

With global climate change, transmission grids are exposed to an increasing number of extreme events, especially ice storms. Usually, contingency plans are developed for extreme events in order to minimize the significant loss of critical loads in transmission grids due to ice disasters. However, the contingency plans are formulated under the constraint of average load capacity. In practice, however, the load capacity varies with meteorological changes, and the execution of the plan may not be effective or even risky. Therefore, this paper proposes a two-stage transmission grid regulation strategy to address this challenge. In the first stage, the transmission grid administrator (TSO) forms typical fault scenarios based on meteorological conditions and historical data and forms a corresponding prognosis plan based on the average load capacity. Due to the updating of the ice disaster information, in the second stage, cascading faults caused by the reduction of the carrying capacity are considered, which indicates the necessity to consider the real-time changes in the ice disaster information if the grid is not able to withstand this risk. Finally, the improved IEEE RTS-79 node system is simulated, and the results show that the change of carrying capacity in the proposed grid regulation strategy has a significant impact on the preplanning plan.