Resilience and Stability Analysis of Distributed Secondary Controllers in DC Microgrids Under Cyber Attacks and Communication Delays

The DC microgrid systems include power electronic converters with information and communication technology. The performance of the DC microgrids will be determined by how effectively these converters are controlled. These communication protocols that support microgrids based on cooperative control are highly vulnerable to cyberattacks. False data injection attack (FDIA) is a kind of cyber-attack in which attackers attempt to introduce false data into the targeted DC microgrid in order to shut it down and destabilize it. Furthermore, the inherent characteristics of communication networks in microgrids may result in delays or/and packet drops in data transmissions between Distributed Generation Units (DGU). These network issues can degrade the stability and control loop performance, resulting in microgrid system uncertainty. Limited papers are available in the literature focusing on resilience against cyber-attacks and communication delays for DC microgrids in one platform. Thus, this paper discusses the impact of FDIAs on parallel DC/DC converter-structured DC microgrids that use droop-based control techniques to sustain the required DC voltage level using voltage observer and current regulator techniques. An unconventional delay-dependent stability condition is formulated and the system's control parameters are adopted using the Lyapunov stability theory and Linear matrix inequality (LMI). The proposed method is tested under various circumstances, physical actions, and cyber-attacks, such as load changing, communication delay, packet loss, time-varying attacks, etc. The outcomes demonstrate the efficacy of the suggested approach in detecting and mitigating the considered attacks in DC microgrids using the MATLAB/Simulink tool.