Operation Optimization Strategy of Multi-microgrids Energy Sharing Based on Asymmetric Nash Bargaining

Promoting the efficient use of renewable energy and achieving low-carbon operation has become an important direction for the power system reform. This paper first builds a microgrid model that includes multi-energy synergy between electricity, heat and gas. Considering the optimal dispatch under the carbon allowances and carbon trading, the carbon capture systems and the power-to-gas devices are added to the integrated energy system to reduce carbon emission. Then, based on the Nash bargaining theory, a multi-microgrids energy sharing model is established. Then, the model is decomposed into the sub-problems of the alliance benefit maximization and the cooperative benefits distribution. The alternating direction method of the multiplier (ADMM) is used to solve the problems, effectively protecting the privacies of the different parts. In the sub-problem of cooperative benefits distribution, an asymmetric bargaining method that quantifies the contribution of each participant with a nonlinear energy mapping function is proposed. Each microgrid negotiates with one aother based on its power contribution as the bargaining power to realize the fair distribution of cooperative benefits. Finally, the simulation results verify the effectiveness of the proposed method. The results show that through the proposed energy sharing method, the benefits of the microgrid alliance are maximized and the microgrid operating costs are significantly reduced. The benefits of cooperation are fairly distributed based on their contributions. In terms of carbon emissions, the results prove that the carbon capture, combined with the power-to-gas system and the energy sharing method, will effectively reduce carbon emissions of the microgrid. © 2022 Power System Technology Press. All rights reserved.