Resilient Synchronization Strategy for AC Microgrids Under Cyber Attacks
Subham Sahoo, Yongheng Yang, Frede Blaabjerg
Abstract
Although distributed control in microgrids is well known for reliability and scalability, the absence of a global monitoring entity makes it highly vulnerable to cyber attacks. Considering that the detection of cyber attacks becomes fairly easy for distributed observers, a well-planned set of balanced attacks, commonly termed as stealth attack, can always bypass these observers with the control objectives being successfully met. In this letter, a mitigation technique is thus introduced to remove stealth attack on the frequency control input in ac microgrids. The mitigation is carried out using a novel event-driven attack-resilient controller for N cooperative grid-forming converters, which guarantees resilient synchronization for up to N - 1 attacked units. Finally, the resilience capabilities and robustness of the proposed controller are discussed and verified under various scenarios.