Switching attack modeling and vulnerability analysis of generator for dynamics study

This paper presents novel insights about cyber-attacks in the power network and their consequence in terms of stability. Compared to existing cyber-attack related studies in power systems, the work discusses switching attack construction and evaluates the impact on generator dynamics. As such, the study is in two folds: (i) switching attack construction, with selection of switching instants based on system states and (ii) vulnerability analysis of power system components, circuit breaker, governor system and excitation system of generators. The role of inherently present communication delay/state variable delay becomes important as it has direct impact on dynamic performance of the system. The impact of the constant and timedependent delay on the stability is addressed by determining the time-delay margin using Lyapunov-Krasovskii functional. Thereafter, the condition for successful switching attack construction is given in terms of delay margin. The accuracy of the derived condition for successful switching attack is demonstrated via real-time co-simulation (RTDS) and MATLAB software. The vulnerability of power system components in IEEE 3-machine, 9-bus network are analysed as individuals or their combinations when subjected to switching attacks. The adequacy related to power system stability as a consequence of cyber-attacks is investigated with an estimation of RoCoF of generators.