An SDN-based Framework for Cyber-physically Coordinated Voltage Support of Virtual Power Plants Against DoS Attacks

The integration of distributed energy resources (DERs) into smart grids is accelerating worldwide. However, the growing reliance on information and communication technologies (ICTs) for real-time monitoring and control in large-scale DER aggregations introduces significant cybersecurity risks. Among these, denial-of-service (DoS) attacks pose a critical threat, with the potential to severely disrupt system operations. To address these challenges, this paper proposes a security-by-design framework for large-scale DER aggregation in the context of virtual power plants (VPPs), with a focus on enhancing the resilience of voltage support services. Central to this framework is a cyber-physical coordinated control architecture that leverages software-defined networking (SDN) to dynamically adapt to variations in both the cyber and physical layers. Specifically, a cyber-aware voltage control algorithm is developed to coordinate DERs based on the real-time status of the communication network, while a physically informed network configuration algorithm adjusts communication paths according to voltage support priorities. The proposed approach is evaluated through cyber–physical co-simulations on both the IEEE 123-bus test system and the 240-bus test system, based on a real-world distribution system located in the Midwest U.S., under server DoS attack scenarios. Results demonstrate that the SDN-enabled coordination significantly mitigates server DoS attacks, confirming the framework’s effectiveness and robustness. This work offers a scalable and resilient solution for securing large-scale DER aggregation and integration against evolving cyber threats.