Cyber-Physical Power System Modelling and Digital Co-Simulation for Grid Operation

The rapid digitalisation of modern power systems has transformed conventional grids into cyber-physical power systems (CPPS), where physical power networks are tightly integrated with communication, computation, and control infrastructures. While this integration enables advanced monitoring, coordination, and large-scale deployment of distributed energy resources (DERs), it also introduces new vulnerabilities and uncertainties arising from complex cyber–physical interactions. In particular, the propagation of cyber contingencies and multi-source uncertainties in CPPS and their impacts on system operation remain insufficiently understood.
This thesis investigates modelling, analysis, and real-time simulation methodologies for CPPS, with a focus on distribution networks and microgrids. A general cyber-physical modelling framework is developed by coupling differential–algebraic equation (DAE)-based power system models with discrete-event communication network models. Within this framework, node-specific communication delays are used to represent cyber physical
interactions. Based on this framework, a virtual–physical power flow method is proposed to analyse CPPS contingencies and vulnerabilities under coordinated cyber and physical disturbances. A composite vulnerability index incorporating voltage deviation, communication latency, and cyber–physical node betweenness is further developed to identify critical components under cyber contingencies.
To quantify uncertainty impacts, a global sensitivity analysis method based on probabilistic modelling and Sobol’ indices is introduced. Uncertainties in load demand, photovoltaic generation, and communication delays are modelled using suitable probability distributions, and a Monte Carlo-based approach is applied to evaluate their influence on system dynamics. Results show that photovoltaic uncertainty dominates bus voltage variation, while communication delays mainly produce localised effects on voltage stability and non-negligible impacts on frequency dynamics.
To validate the proposed methods, several real-time cyber-physical co-simulation platforms integrating OPAL-RT or Typhoon HIL with EXata or OMNeT++ are developed using different synchronisation schemes. These platforms enable realistic emulation of cyber attacks and demonstrate the effectiveness of the proposed methodologies for CPPS vulnerability assessment and cybersecurity analysis.