Coordinated Charging of Electric Vehicles for Congestion Prevention in the Distribution Grid

TLDR

Distributed energy resources such as electric vehicles can provide renewable integration and ancillary services, yet their peak‑hour demand can strain distribution grid capacity. The study seeks to coordinate EV owners, fleet operators, and distribution system operators within a distribution‑grid capacity market, balancing driving needs, charging costs, and thermal limits. The authors propose a theoretical market framework where fleet operators guarantee drivers’ requirements and procure low‑cost energy, while coordinating with the distribution system operator through a capacity market scheme, and present a mathematical formulation of this scheme. Case studies demonstrate the effectiveness of the proposed coordination scheme.

Abstract

Distributed energy resources (DERs), like electric vehicles (EVs), can offer valuable services to power systems, such as enabling renewable energy to the electricity producer and providing ancillary services to the system operator. However, these new DERs may challenge the distribution grid due to insufficient capacity in peak hours. This paper aims to coordinate the valuable services and operation constraints of three actors: the EV owner, the Fleet operator (FO) and the Distribution system operator (DSO), considering the individual EV owner’s driving requirement, the charging cost of EV and thermal limits of cables and transformers in a distribution grid capacity market framework. Firstly, a theoretical market framework is described. Within this framework, FOs who represent their customer’s (EV owners) interests will centrally guarantee the EV owners’ driving requirements and procure the energy for their vehicles with lower cost. The congestion problem will be solved by a coordination between DSO and FOs through a distribution grid capacity market scheme. Then, a mathematical formulation of the market scheme is presented. Further, some case studies are shown to illustrate the effectiveness of the proposed solutions.