5 Conclusions
We study the reliability and cascading risk of a smart gird system in which a cyber network overlays a grid network. To check the network reliability against random nodes failures, we estimate the fraction of nodes that still remain functional after the cascading failures process stops, and then we can obtain the correct results by simulation experiment. Our findings show that there is always a critical threshold value. If the percentage of failing nodes is greater than the critical value, the interdependent smart gird systems will collapse. Our theory analysis and simulation experiment also show that, if both networks satisfy the same degree distribution, the system reliability does not have the direct connection with the system size. However, our proposed analysis model still has some limitations which could be our future work. For instance, we consider both networks are ER networks while the realistic settings are scale-free. Meanwhile, the giant components could not always work in reality. It is also of interest to study models that are more realistic than the existing ones in this paper. Clearly, there are still many open questions about interdependent smart grid systems. We are currently investigating related work along this avenue.
