A Hybrid Model for Analysing Disturbance Propagation in Cyber-Physical Energy Systems

Future power systems are expected to depend more on ICT for essential grid services such as voltage and frequency control, increasing the interdependencies between both systems. Therefore, disturbances from one system could propagate and impact the other, degrading the state of the interconnected system. This paper proposes a formalised hybrid model for analysing the impact and propagation of disturbances in a cyber-physical energy system. The states representing the performance of ICT-enabled grid services are modelled using a finite-state automaton. The impact of power system operational decisions in response to disturbances using these grid services are modelled using an optimisation considering situational awareness. The output from both models is used as input to a hybrid automaton that determines the state of the overall cyber-physical energy system. The model is verified by a proof of concept using state estimation and congestion management as exemplary grid services.