Three-Stage Distribution Feeder Control Considering Four-Quadrant EV Chargers

With the increased penetration of electric vehicle (EV) chargers in distribution systems, there is a need to understand and minimize their impact on medium-voltage (MV) and low-voltage (LV) networks. Thus, this paper proposes a three-stage algorithm to coordinate the operation of four-quadrant EV chargers with other volt/var control devices in MV and LV distribution feeders. The first stage operates on a day-ahead basis and defines the load tap changer and capacitor schedules while minimizing the peak load associated with EVs in the distribution system. The second and third stages update their operation every five minutes, to fairly allocate the aggregated and individual EV loads in the MV an LV feeders, respectively, while minimizing active power losses and voltage deviations. The proposed technique is applied to CIGRE's North-American MV and LV benchmark systems to demonstrate its ability to properly allocate EV loads, and improve distribution system performance in terms of losses and voltage deviations.