Distributed Optimal Control for Multiple Microgrids in a Distribution Network

The ever-increasing demand for more reliable and flexible energy supply for customers has pushed up the microgrids (MGs) to the center stage in the developments of distribution networks. If managed and coordinated efficiently, MGs can provide distinct benefits to the suppliers as well as energy consumers. In this paper, a distributed optimal control framework is proposed to coordinate the multiple MGs in a distribution network as well as to achieve the optimal control within the MGs. For each MG, a two-level control methodology is adopted. The upper-level control optimizes the generation output of multiple MGs cooperatively in a distributed manner, while the lower-level control tracks the optimal generation setting of each generator in the MG under both the grid-connected and islanded modes. The proposed control facilitates the autonomous operation of MGs in the distribution network while still achieves the optimal operation. Simulation studies with a four-MG system demonstrate the effectiveness of the proposed distributed approach.