Structural dependability analysis in smart grid under simultaneous failures

The pervasive use of information and communication technology (ICT) in the future power grid introduces new dependencies and new failure patterns. The simultaneous failure of several nodes may become more likely as devices get more complex and increasingly interconnected. Several studies investigated the behavior of power grids under simultaneous failures. However, the commonly used measure to quantify the outcome is agnostic to important characteristics of the power grid and its interpretation for dependability analysis remains unclear. We introduce two new measures which take the most fundamental characteristics of the power grid into account: the connectivity to power sources and the balancing of load and production. We analyze the two measures in scenarios with random and intentional node failures and conclude, that they are suitable for structural dependability and survivability analysis of power grids. Further, we use the new measures to quantify the potential dependability increase when using the smart grid services Demand Response (DR) and Distributed Energy Resources for failure mitigation. We find that a load reduction with DR by 20% may already achieve a large part of the possible dependability increase with Demand Response.