A Multi-Stage Resilient Optimization Method for Coupled Electric-Gas System Based on Island Division

The growing adoption of natural gas in power systems has led to a heightened focus on the resilience of coupled electric-gas system when confronted with large-scale faults during extreme disturbances. In this study, we examine the sequential recovery procedure of a coupled electric-gas system after experiencing severe faults. We propose an optimization method to enhance the resilience of the coupled electric-gas system. This approach integrates remote switching and isolated island to attain swift fault isolation and restoration. The primary goal is to enhance the system's resilience to extreme incidents and expedite its recovery. Firstly, a model for a coupled electric-gas system is developed to represent the power system, natural gas system, and energy conversion center. Subsequently, detailed models are created for the load shedding phase, fault isolation phase, and service recovery phase that occur in the coupled electric-gas system following extreme faults. These models encompass the topological constraints, power constraints. To illustrate the strategy for improving the resilience of the coupled electric-gas system, we employ practical examples involving the IEEE 33-node power system and a 7-node natural gas system. The simulation results indicate that this strategy effectively improves system resilience.