Enhancing flexibility in distribution networks and charging stations through coordinated optimization with EV cluster integration

With the large-scale integration of electric vehicles (EVs), the demand for flexibility resources in power systems has grown significantly, highlighting the urgent need to enhance AC/DC distribution network flexibility. This paper explores enhancing distribution network and charging station flexibility through coordinated optimization involving EV cluster integration. First, an EV charging and discharging control model is developed, considering user participation willingness while ensuring travel demands are met. Additionally, a vehicle-to-grid (V2G) scheduling strategy for EV clusters is proposed to further improve flexibility. Next, various flexibility resources, including controllable distributed generation, battery energy storage, EV clusters and VSC converters, are incorporated into a multi-objective optimization scheduling model. The model aims to minimize system operation costs and maximize flexibility adequacy while accounting for penalties related to wind/PV curtailment and load shedding. The proposed method is validated through a case study on a 47-node AC/DC distribution network, analysing the impact of different EV user participation levels and access numbers on flexibility enhancement.