Models and techniques for the reliability analysis of the smart grid

Calculating the reliability of the power grid is difficult because it is made up of thousands of components and even though the failure mode of each component may be known, they are not independent of each other. Thus the models required to conduct reliability analysis are difficult to develop and are often complex enough to make the techniques for analysis very cumbersome. Usually controllers like protection relays have been considered more such components and their failures taken into account. However, these independent relays and other controllers are morphing into more complex control systems that can be considered a layer of cyber system that overlays the power grid. This means that the failure modes of these relays and controls are no longer independent but are causally connected to each other through software and communications. In this presentation, we will discuss the models and methods of reliability analysis that are used today, how these models and analysis are being complicated by the growing cyber layer as a result of the move towards a smart grid, and what some of the directions of research may be to surmount the difficulties of analyzing this cyber-physical system.