Day-ahead and intra-day coordinated optimal scheduling of stand-alone microgrid considering unit flexibility

As one of the effective means to effectively use distributed energy and supplement the flexibility of large power grid, the optimal scheduling of microgrid has received more and more attention. On the basis of comprehensive consideration of scheduling flexibility of various distributed resources, an optimal scheduling model of stand-alone microgrid is built from two time scales of day-ahead and intra-day, which takes the minimum total operation cost as its objective. The day-ahead scheduling provides reference for intra-day scheduling, and the start-stop state of the distributed resource that satisfying flexibility requirement can be adjusted in the intra-day scheduling if necessary. The rolling optimization mode is adopted in the intra-day scheduling, and the adjusting priority of various distributed resources is made to guide the optimal adjustment of intra-day scheduling. The initial state of charge of the storage battery is taken as the optimal variable, which is optimized together with the scheduling of the distributed resources to further improve the operation economy of microgrid. The model is linearized and CPLEX solver is applied to solve the mixed integer programming problem. The results of case analysis verify the rationality of the proposed scheduling strategy. © 2020, Electric Power Automation Equipment Press. All right reserved.