The Impact of Size and Inhomogeneity on Power Transmission Network Complex System Dynamics

With ever growing networks in critical infrastructure systems, the impact of network characteristics such as size and homogeneity on their complex system dynamics and risk of failure becomes crucial. In this paper we investigate the effect of highly inhomogeneous network structures, characteristic of some types of real world systems, on the robustness of the power transmission grid using a complex system model of the power transmission system (OPA). It is found that as the system structure is varied from homogeneous to heterogeneous and compared to multiple unconnected small networks with the same aggregate size, the risk can undergo large changes. The unit size of the homogeneous parts of the inhomogeneous system appears to be very important in determining whether large blackouts become more likely as the system becomes more homogeneous or inhomogeneous.