Coordinated Optimization of Hydrogen-Integrated Multi-Microgrids Considering Power Interaction and Variable Efficiency

Under the background of the energy system's transition to new energy driven by the dual carbon goals, green hydrogen energy has become a key carrier for energy transition. However, existing studies on the operation and dispatching of hydrogen-containing integrated energy systems suffer from inadequate consideration of the energy consumption characteristics of electrolyzers and the lack of a coordination mechanism for multi-microgrids. To address these issues, this paper constructs a coordinated optimal operation model for hydrogen-containing multi-microgrids considering electrical energy interaction. First, a multi-operating condition model for the proton exchange membrane (PEM) electrolyzer is established, in which its variable efficiency characteristics are taken into account and the efficiency differences under different operating conditions are characterized by a piecewise method. Second, with the minimum daily operation cost of the microgrid cluster as the objective, a day-ahead scheduling objective function incorporating the costs of wind and solar curtailment, grid power purchase, electrolyzer operation and penalty costs for operating condition conversion is built, and corresponding constraints are set for fuel cells, electric and hydrogen energy storage, grid power purchase, electrical energy interaction among microgrids and power balance. Finally, the problem is transformed into a mixed integer linear programming (MILP) model and solved by the Cplex solver. The case study verifies that the scheme considering the dynamic efficiency of electrolyzers and allowing electrical energy interaction among microgrids achieves the lowest operation cost, which can significantly improve the renewable energy accommodation capacity and reduce the costs of power purchase and hydrogen production. This verifies the effectiveness of the proposed model and provides theoretical and methodological support for the engineering-oriented dispatching of hydrogen-containing integrated energy systems.