Resilient Cyber-physical Systems Research Articles

Micro Synchrophasor-Based Intrusion Detection in Automated Distribution Systems: Toward Critical Infrastructure Security

Because electric power distribution systems are undergoing many technological changes, concerns are emerging about additional vulnerabilities that might arise. Resilient cyber-physical systems (CPSs) must leverage state measures and operational models that interlink their physical and cyber assets, to assess their global state. Here, the authors describe a viable process of abstraction to obtain this holistic state exploration tool by analyzing data from micro-phasor measurement units (μPMUs) and monitoring distribution supervisory control and data acquisition (DSCADA) traffic. To interpret the data, they use semantics that express the specific physical and operational constraints of the system in both cyber and physical realms.

Wide-Area Control Resiliency Using Redundant Communication Paths

With significant investment made in the U.S. in deploying synchrophasor measurement technology, more wide-area measurements will be available and controls based on these signals are likely to be adopted. Communication systems play a critical role in interactive grid control as an indispensable medium to transmit wide-area measurements; however, they are vulnerable to disruptions leading to the risk of destabilizing power systems. This work addresses a critical issue related to engineering resilient cyber-physical systems. The proposed framework utilizes a hierarchical set of wide-area measurements for control and employs channel switching based on mathematical morphology identification to counteract the impact of communication failures on control effectiveness. The proposed control framework incorporating a set of synchronized wide-area measurements is designed to consist of multiple single-input single-output supplementary damping controllers associated with a static VAr compensator. This work is particularly important with regard to leveraging the large investment in installing phasor measurement units across the nation.

Resilient dependable cyber-physical systems: a middleware perspective

Abstract In this paper, we address the role of middleware in enabling robust and resilient cyber-physical systems (CPSs) of the future. In particular, we will focus on how adaptation services can be used to improve dependability in instrumented cyber-physical systems based on the principles of “computational reflection.” CPS environments incorporate a variety of sensing and actuation devices in a distributed architecture; such a deployment is used to create a digital representation of the evolving physical world and its processes for use by a broad range of applications. CPS applications, in particular, mission critical tasks, must execute dependably despite disruptions caused by failures and limitations in sensing, communications, and computation. This paper discusses a range of applications, their reliability needs, and potential dependability holes that can cause performance degradation and application failures. In particular, we distinguish between the notion of infrastructure and information dependability and illustrate the need to formally model and reason about a range of CPS applications and their dependability needs. Formal methods based tools can help us design meaningful cross-layer adaptation techniques at different system layers of the CPS environment and thereby achieve end-to-end dependability at both the infrastructure and information levels.