Economic Schedule of a Microgrid with Load Flexibility Based on Rolling Robust Optimization

This paper investigates a robust economic schedule scheme for a grid-connected microgrid with high penetration of distributed energy resources (DER) and flexible loads. The schedule scheme seeks to minimize the overall costs of load consumption by controlling the resources of flexibility including an EV fleet, an aggregation of cooling appliances, a battery storage system, and the power exchange with public grid. The demand in the microgrid is first fulfilled by the local DER, and the net demand is balanced through an intraday market with real time pricing. A two-stage robust optimization (RO) formulation is proposed to take account of the uncertainty due to forecast errors of load consumption and renewable energy generation. Instead of the RO approach considering the worst scenario, a weak robust optimization (WRO) is proposed and solved using a modified constraint-and-column generation (C&CG) algorithm. A case study is conducted on a test microgrid to validate the efficiency and robustness of the proposed method.