Flexible Redundancy Generation for Virtual Network Embedding with an Application to Smart Grids
Allan Almeida Santos, Amr Rizk, Florian Steinke · 2020
Embedding applications consisting of interconnected logical function blocks, denoted Virtual Network Requests (VNR), onto physical compute and communication networks, denoted Substrate Networks (SN), allows for the automatic generation of a variable degree of redundancy. The need for this feature arises for instance in smart power distribution grids with many decentral devices. Their heterogeneous communication interconnections often feature low reliability and face frequently changing conditions. At the same time, high service reliability is required for critical applications such as voltage control. In this work, we show how to detect potential voltage violations in a medium voltage feeder with high probability at low monitoring cost. We employ a probabilistic power flow model to determine the time-dependent required reliability for the links of voltage monitoring VNRs and embed it onto a SN consisting of a mix of plausible smart grid communication technologies. We use a novel approach based on chance-constrained mixed integer linear programming to generate a minimal, but sufficient degree of redundancy. This allows for optimal resource usage of the SN, flexibility to adapt the embedding in case of changes of the VNR or SN parameters, and reduced design efforts in comparison to manual redundancy planning. Compared with a static redundancy setup, the operational communication costs can be more than halved in our simulation experiments.