Improved operation of power distribution systems by the use of flexibility services and energy communities

This thesis investigates the operation of distribution systems incorporating flexibility service providers and renewable energy communities (RECs). It is structured in two main parts. The first part focuses on flexibility operations in electric vehicle (EV) parking lots (PLs) equipped with multiple charging stations. Due to uncertainties in EV arrivals and characteristics, a multistage stochastic approach is developed for day-ahead scheduling, enabling the calculation of the maximum flexibility PLs can offer to the distribution system operator (DSO). A k-medoid clustering method is used to reduce computational time. Flexibility is defined as the PL’s capacity to adjust power upon DSO request, with energy recovery to ensure EV charging requirements. The DSO leverages this flexibility, along with that from distributed energy resources (DERs), to optimize the voltage profile of the grid. A decentralized, multi-objective optimization framework is applied to a 24-hour simulation on the IEEE 123-node test feeder. Results show significant voltage profile improvements compared to scenarios without optimization. The second part explores reactive power services from RECs in medium-voltage networks. By coordinating active and reactive power exchanges among prosumers—particularly photovoltaic (PV) systems with battery energy storage (BESS)—RECs reduce penalties from low power factor operation. Voltage support is further enhanced using on-load tap changer (OLTC) transformers. Case studies include feeders in the Modena distribution network connected to a common substation. The findings confirm that RECs can reduce the need for new reactive compensation devices by effectively coordinating distributed generation. Additionally, the study examines the operation of multiple RECs within a single network. A novel pricing mechanism based on shadow prices of balancing constraints is proposed to ensure fair benefit distribution among members. While RECs significantly lower energy procurement costs, these benefits decrease as the number of communities in the same grid increases.