Physics-informed cyber-physical security in smart grids

Nafees, Muhammad Nouman 2025. Physics-informed cyber-physical security in smart grids. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Cyber-Physical Systems (CPS) have become the organising fabric of critical infrastructure. However, as control logic, communications and physical processes are ever more tightly interlinked, their security becomes more critical yet more fragile. Smart grids epitomise the CPS security challenge: Wide-area control measurements expose power system dynamics to an adaptive adversary. Within this setting, Automatic Generation Control (AGC) acts as a spatiotemporal feedback mechanism, maintaining system frequency and regulating tie-line exchanges. False Data Injection (FDI) attacks, in particular, corrupt AGC measurements with fake transient values that remain consistent with physical behaviour. Much of the literature treats cyber and physical behaviour in isolation: Even worse, the stealthy, physics-consistent evolution of such attacks across successive control intervals is often neglected. Empirically, the study, therefore, engages researchers and practitioners, collecting their perspectives on CPS and smart grid security, on how adversaries are conceptualised, and on how threat landscapes, threat models and detection strategies are framed in practice. The crux of this empirical work, therefore, is a physics-aware conception of cyber-physical situational awareness, in which AGC behaviour, tie-line flows and protection constraints are treated as prior information about admissible operation. In this sense, the normal spatiotemporal evolution of the system becomes the reference for interpreting subtle drifts and delayed manifestations of compromise. Building on this foundation, this thesis, therefore, develops an optimised FDI attack model that injects coordinated falsifications at successive AGC control intervals, subject to power system dynamics, operational thresholds, relay limits and stochastic noise. In so doing, it shows how modest perturbations, shaped in space and time, can accumulate into severe yet apparently benign disturbances. In parallel, the work develops physics-informed defence mechanisms in which domain constraints, operating points and AGC-related quantities enter as structured prior information for temporal models, improving detection performance across standard metrics, including false positives, while increasing sensitivity to coordinated intrusions. Overall, the work advances a view of CPS and smart grid security through the lens of physics-informed defence.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Computer Science & Informatics
Subjects:	Q Science > QA Mathematics > QA75 Electronic computers. Computer science Q Science > QA Mathematics > QA76 Computer software
Date of First Compliant Deposit:	9 February 2026
Date of Acceptance:	2 February 2026
Last Modified:	10 Feb 2026 08:51
URI:	https://orca.cardiff.ac.uk/id/eprint/184550

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