Improving distribution system flexibility using electric vehicles under the distributed energy resource management system framework

We propose a new system for improving distribution system flexibility using electric vehicles (EVs) under the distributed energy resource management system (DERMS) framework. The proposed DERMS framework comprises four hierarchical levels: device, aggregation, operational, and enterprise, with an optional virtual level. We implement a comprehensive process focused on EV flexibility under the proposed DERMS framework. The system mechanism is divided into an upstream process, which transmits data information, and a downstream process, which commands control signals. To encourage the use of EV flexibility, we use an online opportunity cost-based quantification method. In the downstream process, the EV flexibility dispatch problem is sequentially addressed at the enterprise and operational levels. This process is validated for both charging control only and charging and discharging control cases on the IEEE 33-bus system, demonstrating its effectiveness in improving grid flexibility through EV integration. Furthermore, the system's adaptability and scalability were validated on the IEEE 69-bus weakly meshed network.