Coordinated Scheduling of Multiple Frequency Services in Electricity-Gas-Hydrogen Systems Based on Federated Warm Starts

The high penetration of renewable energy and variable load profiles in modern power systems call for enhanced frequency security in the event of large and sudden power disturbances. Integrated energy systems, with the introduction of external energy networks, hold strong potential for mitigating frequency deviations. This paper proposes a coordinated scheduling framework of multiple frequency services in an electricity-gas-hydrogen coupled integrated energy system based on federated warm starts. On top of the scheduling model of a closed-loop electricity-gas-hydrogen system, we formulate the set of frequency security constraints as linear/bilinear constraints, where generators and electrolyzers with heterogeneous frequency support capabilities collectively contribute to enhanced/primary frequency control. In terms of the bilinear term in the reconfigured nadir frequency constraint, we propose a SplitNN-based federated learning framework to allow the energy systems to collectively generate warm starts for the bilinear variables in a privacy-preserving manner, with which the McCormick envelope can be significantly tightened. Case studies show that the electrolyzers in the hydrogen system can significantly mitigate frequency deviations, while the proposed warm start approach achieves a higher accuracy and computational efficiency.