Signal Temporal Logic-Based Attack Detection in DC Microgrids

A Stealth Cyber-Attack Detection Strategy for DC Microgrids

“…Assuming a pre-condition that the system always operates at a certain global reference voltage is known to each agent, (11) should be a sufficient criteria to justify that the system is attacked by an external entity. Many likely potential attacks on DC microgrids such as FDI & DoS [32], jamming [33] and distributed DoS [34] attacks have already been well studied in the literature. These attacks can be caused using several cyber-physical amendments such as jamming of cyber link, loss of measurements, data-packets flooding, compromised communication servers, sensors, etc.…”

“…These attacks can be caused using several cyber-physical amendments such as jamming of cyber link, loss of measurements, data-packets flooding, compromised communication servers, sensors, etc. However, the authors in [32], [33] have already established that such attacks disrupt the cooperative synchronization law [30], which can be easily detected since (10) is violated. To provide with a detailed explanation, the abovementioned disturbances introduce an uncoordinated discontinuity in updating (5) which disrupts the consensus between agents, ultimately leading to (11).…”

“…However, under worst cases, C i (k) can also be manipulated by the attacker using subtraction to make it negative, which displeases our attack detection criteria. To handle these discrepancies, C i (k) is tactically added to e i 2 (k) in (8), which can now be rewritten as (32) such that the control operation will be disoriented locally, thereby allowing the agents to reliably detect the attacks. Since I dc ref = 0, the cross-coupling of the CVF suggested in (32) will supplement to accurate detection and facilitates protection against attacks on CVF since C i (k) now forms the forward path between both secondary control sublayers.…”

“…To handle these discrepancies, C i (k) is tactically added to e i 2 (k) in (8), which can now be rewritten as (32) such that the control operation will be disoriented locally, thereby allowing the agents to reliably detect the attacks. Since I dc ref = 0, the cross-coupling of the CVF suggested in (32) will supplement to accurate detection and facilitates protection against attacks on CVF since C i (k) now forms the forward path between both secondary control sublayers. By doing so, further attacks on C i (k) will disorient the objectives laid down for the outer voltage controller in sublayer I since it disregards (10).…”

“…To test the robustness of the proposed approach under worse case scenarios, another consecutive attack at t = 2 s is preempted by the attacker to manipulate C 3 by reducing it to a negative value. However, due to cross-coupling of C i (k) into sublayer II in (32), it prevents further exploitation as it can't disorient the nested control output for a particular operating point.…”