Coordinated Energy Scheduling in Interconnected Power-Water-Gas Networks Under Network Failures

The rapid growth of interconnections between different energy systems has seen emerging developments in recent years. Electric Power System (EPS), Water System (WS), and Natural Gas System (NGS) have been traditionally operated independently. However, a multi-sectoral approach is needed to enhance the resilience of critical infrastructure systems and reap the economic benefits. This becomes crucial as natural disasters with massive power outages have increased in both frequency and magnitude. To address these challenges, this paper proposes a cooperative joint framework for the operation of the Power, Water, and Gas Networks (PWGNs) during emergency operating conditions. The proposed formulation takes into account the nonlinear nature of both the hydraulic constraints in WS and the gas flow in the NGS. To reduce the computational burden of the original problem, linearization techniques are employed to convert the nonlinear model into a Mixed-Integer Linear Programming (MILP) formulation. Case studies with different contingency scenarios are analyzed in the IEEE 24-bus and IEEE 118-bus test systems, which are jointly operated with a 12-node and 20-node NGS, and a 15-node commercial-scale WS. Numerical results demonstrate that the proposed model effectively enhances the resilience of the interconnected energy systems and reduces the overall operational costs during emergency conditions. Additionally, results show that the proposed joint operation model provides significant energy flexibility and is efficiently scalable to large networks.