Optimal Planning of Multi-Microgrid System with Shared Energy Storage Based on Capacity Leasing and Energy Sharing

Microgrids (MGs) are important forms of supporting the efficient utilization of distributed renewable energy resources (RES). To achieve high proportion penetration of distributed RES and improve the system efficiency, this paper focuses on the multi-microgrid (MMG) system with shared energy storage (SES) and an optimal planning method of MMG system with capacity leasing and energy sharing for PV carrying capability enhancement is proposed. Firstly, a collaborative optimization framework between the multi-microgrid operator (MMGO) and the shared energy storage operator (SESO) is proposed. Secondly, the PV carrying capability index is proposed from two dimensions: the hosting capability and the accommodation capability, and the capacity planning model of the MMG system considering PV carrying capability index is established. Then, the capacity leasing and energy sharing model among MGs as well as between MMG systems and SES system is established. Based on this, a collaborative capacity planning model of MMGO and SESO with the Nash Bargaining game is developed and a distributed solution algorithm is designed. Finally, through a comprehensive case study we can draw that, the proposed planning method with capacity leasing and energy sharing can enhance PV carrying capability of the MMG system while improving economics of MMGO and SESO.