Low-carbon optimization of multi-microgrid system operation considering supply–demand bidirectionality based on Nash bargaining

Multi-microgrid (MMG) systems facilitate efficient and clean energy utilization. To address the current limitations in harnessing the interaction potential between supply and demand sides, as well as the absence of carbon trading among microgrids (MGs) and carbon responsibility recognition for users, this paper proposes a low-carbon optimization strategy for MMG systems based on Nash bargaining, which considers bidirectional interactions between supply and demand. On the supply side, carbon quotas are traded among MGs through bargaining-based carbon trading mechanism, while on the demand side, an integrated demand response model is developed using carbon emission flow theory to accounts for users' carbon responsibilities. A Nash bargaining model is then constructed to enhance the interaction capabilities between MMGs and load aggregator (LA). To ensure privacy for both MGs and the LA, the Nash bargaining model is decomposed into two tractable subproblems and solved using the alternating direction method of multipliers (ADMMs). Case studies and comparative analysis demonstrate that the proposed strategy strengthens interactions among MGs and also interactions between MG and LA. The implementation of carbon trading among MGs and user carbon responsibility improves economic benefits by 23.3% and reduces carbon emissions by 7%.