Hydrate-Constrained Optimal Power Flow for Integrated Electricity and Natural Gas Systems

As a transitional scheme in the energy transition, the integrated electricity and natural gas systems can significantly enhance energy supply security and utilization efficiency. However, as an energy carrier, the physical properties of electric energy are quite different from those of natural gas. During the natural gas transmission process, gaseous flows may form solid hydrates, blocking pipelines and rendering formulated operational strategies ineffective. The fundamental problem lies in the failure to incorporate hydrate-induced pipeline blockages in gas transmission systems into the optimal operation framework of integrated electricity and natural gas systems. Therefore, this paper proposes an optimal energy flow model for integrated electricity and natural gas systems designed to prevent natural gas hydrate formation. Firstly, according to the mapping relationship between gas pressure and gas temperature in the critical state of hydrate formation, the hydrate formation constraint is constructed, and the influence of this constraint on the operation domain of components is analyzed within the integrated system. On this basis, a novel model is proposed that the hydrate-constrained optimal energy flow for integrated electricity and natural gas systems. Simultaneously, the intractable parametric exponential constraints in the model are reformulated into linear functions to reduce the computational complexity of the optimization problem. Numerical results demonstrate that the proposed methodology effectively prevents natural gas hydrate formation across diverse operational scenarios while ensuring the reliable implementation of optimal energy flow strategies in integrated systems.