On Detection of False Data in Cooperative DC Microgrids—A Discordant Element Approach

Abstract

Though recent advancements in DC microgrids are largely based on distributed control strategies to enhance reliability and scalability, the absence of a centralized controller to check the global information makes these schemes highly susceptible to cyber attacks. Since false data injection attacks (FDIAs) are considered as a prominent attack methodology in DC microgrids, prior emphasis is usually laid on compromised sensors and controllers only related to DC voltages. Hence, this paper firstly segregates the FDIAs on the output currents into destablization and deception attacks, based on the modeling of attack elements with respect to the consensus theory. Secondly, a discordant element based detection approach is designed to detect the attacked nodes accurately, using an extended analysis of the cooperative control network. A risk assessment framework for DC microgrids against cyber attacks is provided alongside all the case studies. An evaluation theory is also presented to assist the proposed detection scheme to differentiate between cyber attacks and faults. Further, the proposed detection approach is theoretically verified and validated using simulation and experimental conditions.

An Event-Driven Resilient Control Strategy for DC Microgrids

“…where v i (t) = V dci (t) + j Mi u V i (t) with V dci denoting the measured output voltage of i th agent. [14] of unit I and III at t = 1 sec and, current sensor and outgoing communication link [15] of unit II at t = 1 sec with attack II around t = 5 sec -Conventional event-triggered philosophy [22] can not discriminate between a load change and stealth attack since the objectives in ( 5) are met satisfactorily. [14] AND [15] Affected Counterparts Modeling…”

“…The detection strategies for both the stealth attacks in Table I, have been provided in Table II. More details on its formulation can be referred from [14] and [15]. Upon detection of attack elements, it is vital to remove these attacks as such unbounded signals in the control system may quickly trigger (8)-( 9), ultimately leading to system shutdown.…”

“…3. Proposed event-driven resilient control strategy to mitigate stealth attacks [14], [15] in DC microgrids with N agents.…”

“…Considerable efforts have been put recently in modeling and detection of stealth cyber attacks on various elements (sensors, communication links) in DC microgrids [14], [15]. Further studies on differentiating between sensor faults and cyber attacks is carried out in [16].…”

“…As compared to the conventional event-triggered schemes [22]- [23], attack detection criterion are used as triggering mechanisms for the proposed countermeasures to operate immediately [24]- [25]. As already discussed in [14], [15], since stealth attacks involve compromised sensors, actuators and communication links, activation of these events is defined using the detection criteria for each unit. Further, the activation status of these events in the attacked agent is also transmitted to non-compromised neighbors to authenticate the transmitted measurements as False.…”