Defining a Reliable Network Topology in Software-Defined Power Substations

In recent years, communication networks on modern power substations have grown both in size and complexity, demanding the highest levels of reliability. However, there is no unique criterion to define the structure of the topology in such networks, since in every substation the end user implements their own topology or the topology suggested by a vendor, according to IEC 61850 standard guidelines. This paper proposes a methodology, using integer linear programming, to solve the problem of generating a reliable network topology in a software-defined power substations context. The trustworthiness of the reached solution is evaluated using terminal reliability techniques, graph metrics, and end-to-end time delay performance. The obtained results confirm that the proposed network topology is highly reliable to be implemented in power substations, according to the network redundancy considerations proposed by the IEC 62439 standard, and the operation time requirements suggested by the on IEC 61850 standard. In addition, we present software defined networking-based solutions for loop-based topologies in the proposed network topology, which would be technically unfeasible using traditional network protocols. These solutions include algorithms to solve problems related to the broadcast traffic containment and the diffusion and reliability of the multicast traffic.