Research on Fault Recovery of Electricity-gas Coupled Systems Based on Risk Early Warning

Abstract

To address the large-scale blackout problem caused by cascading faults in the electricity-gas coupled system triggered by extreme weather, this study proposes a long-term phased restoration plan for outage loads through the coordinated operation of soft open points (SOPs) and energy storage devices. Firstly, considering the power flow regulation characteristics of SOPs, the power supply capacity of energy storage, and the safety constraints of the gas network, an optimization model for fault recovery is established, with the objectives of maximizing power supply guarantee rate, minimizing network loss, and ensuring the safe and stable operation of the gas network. Secondly, drawing on the idea of risk prevention and control, a risk assessment model is constructed from two dimensions: equipment operation reliability and fault power loss consequences, and the grey relational improved TOPSIS method is adopted to complete the priority ranking of critical loads. Finally, a phased fault reconfiguration and maintenance strategy coordinated by SOPs and energy storage is formulated, and multi-period rolling optimization is carried out to realize continuous power supply during the maintenance period. Simulation results show that the proposed method can effectively block the cross-domain cascading fault propagation path from the power grid to the gas network, providing technical support for the emergency disposal of large-scale blackout accidents in similar coupled systems