Priority-Based Microgrid Energy Management in a Network Environment

The paper presents a method for energy storage dispatch and sharing of renewable energy resources in a network of grid-connected microgrids. The proposed scheme provides for local inter-microgrid and microgrid-to-grid power transactions, enabling them to collectively share their storage and renewable energy capacity in order to reduce their electricity cost. The storage dispatch commands and the share of local and grid power transactions for the individual microgrids are determined by solving a multi-objective optimization problem over a receding control horizon, using forecasts of the net power demands of the microgrids. This multi-objective optimization is formulated as a lexicographic program, to allow for preferential treatment of groups of microgrids based on pre-assigned priorities. The original optimization model is convex but nonlinear. A linear counterpart of the problem is derived that is suitable for online computation. Numerical simulations with real demand and renewable generation data demonstrate the effectiveness of the proposed strategy in reducing the electricity costs of the microgrids in accordance to their priority in the network.