Unifying Dependability of Critical Infrastructures: Electric Power System and ICT: Concepts, Figures of Merit and Taxonomy

With Smart Grids efficiency of the electric power delivery service can be significantly increased by using advanced ICT infrastructure. The looming danger of merging two critical infrastructures, ICT and electric power, is that dependability may be compromised due to interdependencies and different approaches to dependability in the two communities. This calls for a unified approach to dependability which may be achieved by viewing Smart Grids as cyber-physical systems. We analyze and compare definitions and figures of merit used in ICT and electric power systems´ communities to provide the basis for dependability analysis of Smart Grids. We propose a taxonomy of faults for Smart Grids by examining a large set of previous power system outages. Our work relies on the analysis of relevant events from the past in an attempt to understand present dependability state of Smart Grids and pave the way for proactive grid management.