Abstract
Cyber ranges are increasingly being used for cybersecurity studies in the grid. In this paper we explore the feasibility of building a cyber range for a power grid as a composition of two or more cyber ranges of substations of the grid, where each substation is a sub-grid of the parent grid. We follow this approach as it is a close-to-real-life approach, each substation being represented separately on its own collection of virtual machines and servers, thus permitting faults and attacks to be more realistically supported. Synchronization is fundamental for the feasibility of distributed simulation. If the individual components are not synchronized the cyber range may go into incorrect or inconsistent states. Feasibility may be evaluated by comparing distributed simulation vis-a-vis centralized simulation. In this paper we present definitions of consistency and synchronization, and outline challenges in achieving synchronization across substations. As a starting point for a solution towards addressing the more general problem, we outline an algorithm for achieving synchronization to a desired level of consistency. We present a case study of two substations with results showing comparison between two synchronized simulations vis-a-vis a single simulation for the case of known convergence. The results indicate that this approach is indeed feasible and could be explored further. It is expected that properly configured and synchronized distributed cyber ranges will be a vehicle for robust and high-fidelity cybersecurity experimentation, data collection and training for the power grid.