A novel all-electric-ship-integrated energy cooperation coalition for multi-island microgrids

Studies have demonstrated that using offshore mobile energy storage, i.e., all-electric-ships (AESs) equipped with energy storage batteries, for the energy sharing of multi-island microgrids (MIMGs), may be a more economical approach than laying submarine cables. However, given the individual interests, privacy protection demands, and participation willingness of AESs and MIMGs, existing energy sharing strategies are not suitable for such a specific scenario. To address these issues, this paper proposes a novel energy cooperation coalition comprised of an energy transmission provider (ETP) and MIMGs, where ETP is not only an initiator of the coalition but also an operator for the inter-island energy sharing using its AESs. Furthermore, the energy cooperation problem, including AES’s spatial–temporal coupling model, is reformulated into a two-stage problem of energy scheduling and benefit allocation, and is optimized in a distributed way. Then, an original adaptive enhanced constraint-alternating direction method of multipliers is presented to solve the energy scheduling problem for better convergence. A bi-level benefit allocation mechanism based on asymmetric Nash bargaining is also devised, with a role and energy-based contribution rate and a bilateral incentive strategy to evaluate contributions and ensure cooperative willingness. Finally, numerical simulations verify the effectiveness of the suggested energy cooperation coalition, distributed optimization method, and benefit allocation mechanism.