Multistage optimized planning for the alliance expansion of multiple island microgrids with shared hybrid energy storage systems: A Nash bargaining-based game approach

To reduce the high cost of hybrid energy storage (HES) system composed of a battery (Bat) and a hydrogen storage (HS), multiple privately-owned IMGs form IMG alliances to jointly invest in HES systems to achieve shared hybrid energy storage (SHES) systems. Each IMG's distinct construction time makes IMG alliances expand dynamically, complicating the new IMG's planning scheme and the IMG alliance's SHES expansion scheme. In this case, it is urgent to study how to balance the interests of multi-IMGs through reasonable planning schemes and promote the SHES co-investment of multi-IMGs. A multistage optimized planning method based on Nash bargaining theory is proposed to solve this problem. First, the planning stages are divided based on each IMG's construction start time. At each stage, different IMGs are classified into built IMGs and to-be-built IMGs, which are modelled through distinct objective functions and constraints. To improve the economy of IMG alliances and achieve fair SHES cost allocation to promote SHES co-investment, a Nash bargaining planning model is established. Since different IMGs are invested in by different stakeholders, a privacy-preserving distributed algorithm is adopted to solve the Nash bargaining planning problem. The case study results confirm that multistage Nash bargaining planning improves economic value for multi-IMGs and promotes the SHES co-investment of multi-IMGs. Compared with building own distributed HES, the proposed method results in 27.2 % reduction in economic cost and 8.0 % reduction in HES capacity in stage II, 23.23 % reduction in economic cost and 12.7 % reduction in HES capacity in stage III.