Here-and-Now Wait-and-See Approach for Optimal Scheduling of Energy and Reserve in Distribution Networks

Abstract

This paper establishes a two-stage approach for optimal scheduling of distribution networks considering cost minimization and reliability enhancement. In here-and-now stage, the day-ahead energy and reserve scheduling is performed considering the uncertainties in load demand and renewable energy resources. This approach is a scenario-based one. In energy and reserve provisions, optimal interactions of distribution network with wholesale market, optimal commitment of distributed generation (DG) units and responsive loads (RL), and also optimal reconfiguration of the network are determined. These optimally determined set-points are treated as operation limitations and boundaries in wait-and-see stage. This stage deals with real-time operations. In this stage, two operation modes are explored as normal and faulty conditions. In real-time normal operations, the errors in forecasted load and renewable energy generation are taken into account. Based on the allocated reserve quantities and redispatching of committed DGs and RLs, the deviations are properly accommodated with a least operation cost. In faulty condition, outage of power system components such as distribution feeders is further considered. In this case, the proposed model not only makes benefit of reserve quantities but also proceeds with recommitment of DG units and RLs. Besides these corrective actions, it determines an optimal configuration of the network and ends in the least amount of shed loads, as the last remedy. Based on the numeric results, 7.3% reduction is achieved in total operation cost. Also, the fluctuation in real-time wind power generation is properly managed.