Optimization strategy for power sharing and low-carbon operation of multi-microgrid IES based on asymmetric nash bargaining

Promoting the efficient use of renewable energy and realizing the low-carbon operation of the integrated energy system has become an important direction for the reform of the integrated energy system. In this paper, we firstly construct a microgrid model containing electricity, heat and gas multi-energy synergy, consider the optimal operation mechanism of carbon trading with reward and punishment ladder, and improve the model of CHP units by adding carbon capture system and power-to-gas facility to reduce carbon emissions. Then, a cooperative operation model of multi-microgrid electric energy sharing is established, which is then decomposed into the subproblem of maximizing the benefits of microgrid alliances and the subproblem of distributing cooperative benefits, and the alternating direction multiplier method is selected for distributed solution, so as to effectively protect the privacy of each subject. In the cooperative benefit distribution subproblem, a method is proposed to quantify the contribution size of each participating entity by a nonlinear energy mapping function, and each microgrid negotiates with each other by the size of its electric energy contribution in the cooperation as the bargaining power to achieve a fair distribution of cooperative benefits. Finally, the simulation results verify the effectiveness of the proposed method. The results show that the benefits of the microgrid alliance are maximized by the proposed multi-microgrid power sharing method; moreover, the cooperative benefits of the microgrid alliance are equitably distributed based on the magnitude of the energy contribution of each microgrid; in terms of carbon emissions, the results demonstrate that the carbon capture joint power-to-gas system, as well as the energy sharing method among microgrids, can effectively reduce the carbon emissions during the microgrid operation.