Cyber-physical Modeling and Analysis for Smart Grids: Resiliency & Cyber Securit

Traditional resiliency studies of infrastructure system such as the power grid focused on a context defined by extreme events and natural disasters. However, the increased dependability on cyber tools and networks combined with the rise of serious cyber-based threats thrust resilience to be a strategic approach for planning, design and operation. This dissertation invests on a cyber-physical model of the smart grid and is motivated by the benefits of understanding the interactions between the cyber and physical domains and coordinating adaptive capacity resources for an enhanced resilient operation.;We first consider how to improve the resilient operation of existing power systems. We adopt an energy storage (ESS)-based feedback linearization control to address transient stability. The control is studied in centralized, distributed and decentralized architectures, then the different architectures are recognized as modes of operation of an adaptive controller that responds to cyber and physical disturbances. Observed performance limitations of the proposed control are investigated in our study of cyber-physical interactions. A cyber-physical hybrid graph is constructed based on an equivalent impedance interpretation of a communication link performance in relation to physical power systems' dynamics. The proposed hybrid graph constitutes a representation of the system in the cyber-physical domain. The impact of the ESS-based control in enhancing transient stability is then studied from a resiliency perspective. The combined impact of the ESS, sensory and associated control is analytically studied using a proposed effective virtual inertia measure. The proposed measure reflects the adaptive capacity introduced into the power system by the ESS-based control.;We next consider evolving distribution systems and how coordinated operation of these systems can adopt a resilient-by-design approach. Microgrid networks present a system-of-systems architecture comprised of autonomous entities and distributed built-in adaptive capacity that can be coordinated to achieve further benefits and enhanced resilience. A coalition constrained cooperative game-theoretic distributed algorithm is developed to coordinate resources between microgrids.;Finally, we develop a new class of switching attacks that exploits existing system vulnerabilities using an adversary threat model with limited resources. The study emphasizes the importance of addressing existing vulnerabilities in the power system for an improved resilience.