Distributed Screening of Hijacking Attacks in DC Microgrids

Abstract

It is well known that distributed control can improve the resiliency of DC microgrids against multiple link failures as compared to centralized control. However, the control layer is still vulnerable to cyber attacks. Unlike widely studied false data injection attacks (FDIAs), which involve adding false signals on top of existing ones in the controller or communication links, hijacking attacks completely replace the existing signals. As a result, the compromised agent(s) diverge from steady state owing to imbalance in the iterative rule of consensus algorithm. To detect hijacking attacks, a novel distributed screening (DS) methodology is proposed. In addition to that, a fault detection (FD) metric is provided to assist the proposed attack detection strategy in differentiating between hijacking attacks and sensor faults. This reduces the complexity of decision making in the attack mitigation approach. Further, interoperability of the proposed detection metrics allows simultaneous detection of sensor faults and hijacking attacks. The performance of the proposed detection metrics is evaluated under simulation and experimental conditions to conclude that it successfully detects the attacked agent(s) as well as sensor fault(s).

An Event-Driven Resilient Control Strategy for DC Microgrids

“…Converter outage under attack ! Line-to-line fault DM i < Υ 2 1 A fault detection metric F D i I is proposed in [16] to differentiate between current sensor faults and cyber attacks. 2 A line-to-line fault evaluation theory is proposed in [15] to differentiate between line faults and cyber attacks.…”

“…However, since the detection criteria DM i doesn't exceed the detection threshold Υ for these disturbances, the event-driven mitigation process will not be activated. More details on detection of line-to-line and sensor faults and their differentiation with cyber attacks have been provided in [15] and [16], respectively. Finally, the main features of the proposed event-driven resilient scheme are:…”

“…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]. However, these papers are limited to detection without providing any comprehensive steps of countermeasures for normal system operation to remove the attack element(s).…”

Resilient Operation of Heterogeneous Sources in Cooperative DC Microgrids

“…Since the proposed detection concept for heterogeneous sources (operating with an adaptive droop ∆R i ) is basically inspired from [8] - [9], it is termed as adaptive discordant element (ADE) in this letter, can be mathematically represented for i th agent using Remark II as:…”

A Linear Regression Based Resilient Optimal Operation of AC Microgrids

“…Further, data intrusion from stealth attacks is also possible, as demonstrated in [8]- [12]. Such attacks are capable of increasing the generation cost without causing any obvious indications of power imbalance.…”