Impact of Reactive Power Dispatch in a Recursive Two-Stage Optimal Control Algorithm for Isolated Electrical Networks

The increasing integration of renewable energy sources poses significant challenges for the operation of isolated electrical networks, particularly in ensuring adequate power quality levels. In this regard, this paper explores the role of reactive power dispatch in enhancing the operational performance of isolated networks. To this end, a recursive two-stage optimal control algorithm is adopted to manage the energy resources in the isolated network of a real Italian island. The first stage involves solving an optimal predictive dispatch problem for active power schedule. The second stage refines this dispatch in extended real-time, adapting to changing system conditions and enforcing grid constraints through the formulation of an AC Optimal Power Flow. Through the comparison of two dispatch approaches, the study evaluates the impact of reactive power control under two progressive penetration levels of photovoltaic generation. Specifically, the presented results demonstrate that enabling reactive power support from flexible resources, such as storage systems, improves quality of service levels despite solely active power reserve is considered in the two-stage dispatch.