Vulnerability Analysis of Virtual Power Plant Voltage Support under Denial-of-Service Attacks

Abstract

Virtual power plants (VPPs) are emerging but powerful platforms for large-scale aggregation of distributed energy resources (DERs) that can enhance economic operations and system stability of the smart grid. However, the management of numerous DERs owned and operated by various stakeholders relies on a sophisticated cyber-infrastructure that inevitably increases the attack surfaces and attracts potential threat actors. Among the grid services enabled by VPP, the voltage support - an advanced voltage regulation scheme against major disturbances - can become a prominent target of adversaries due to its dependence on frequent coordination among DER operators. To enable proactive defence against high-risk threats, this paper provides a new investigation of the potential vulnerabilities and patterns of voltage-supporting DERs under denial-of-service (DoS) attacks targeting VPPs in smart distribution grids. We first analyze the state-of-the-art in VPP voltage support and the underlying communication architectures to identify the entry points that can be exploited by DoS attacks. The exploitable vulnerability of this grid service and the patterns of vulnerable DERs in such threats are identified, and a voltage sensitivity-based vulnerability index is proposed to quantify the vulnerability of DERs under DoS threats. To understand the worst-case scenarios, an advanced DoS attack scheme is constructed to effectively deteriorate the capacity of VPP voltage support by targeting only a small set of DERs with the highest vulnerability index. Experiments on a modified IEEE 13-node test feeder are conducted and demonstrate that the targeted DoS attacks can disable most (80-97%) of VPP voltage support capacity by only compromising one or two of the five installed DERs. As one of the first works on VPP cybersecurity, our work aims to facilitate the understanding and mitigation of the security risks of VPPs toward secure integration and operation of DERs in the future grid.