Evaluation of Communication Scenarios Inside the Electrical Power System

The paper presents the modelling and the dependability evaluation of communication scenarios inside the distribution grid of the electrical power system (EPS). In particular, it deals with the communication between one area control centre and a set of substations exchanging commands and signals by means of a redundant communication network. The communication may be affected by threats such as the network failure, or intrusions into the communication, causing the loss of commands or signals. Such scenarios have been modelled and simulated in the form of stochastic activity network (SAN), a particular form of Petri Net (PN), to evaluate in quantitative terms the effect of the threats to the communication. In particular, two measures have been computed: the probability and the number of failures in the communication, as a function of the time.