Stability Investigation of DC Microgrids Under Stealth Cyber Attacks

In a networked DC microgrid, stealth cyber-attacks can easily penetrate into the system and deceive the system observer not only to raise security concerns but also in destabilizing the microgrid. Apart from channeling efforts into ensuring security, considerable focus also need to be put into investigating the impact of stealth attack on system stability simultaneously. Hence, this paper investigates the system stability of DC microgrids for different magnitude of stealth cyber attacks. Firstly, a small signal model of dc microgrid under stealth attack is obtained in this paper. Then, modeling the stealth cyber attack as a non-linear and discontinuous input considering a strategic perspective by the adversary, the describing function method is adopted to analyze the stability of the system. The instability caused solely due to the presence of stealth cyber attacks has been revealed, even though the global consensus should supposedly be met. Finally, simulations are presented to validate the theoretical analysis.