Minimizing Age of Information for Distributed Control in Smart Grids

Exchanging information between actively-managed components is key for establishing distributed control schemes in future Low Voltage Distribution Grids (LVDGs). Each node's measurements and control data has to be disseminated to all other nodes in the electrical grid, to allow for safe operation and control. However, periodic all-to-all flooding procedures are challenging for wireless communication networks and especially so, if end-to-end reliability is required. The effectiveness of a flooding protocol is well captured in the Age of Information (AoI) performance indicator, combining the time it took to disseminate a data chunk and the time in between updates. Existing flooding protocols are not concerned with keeping AoI low in scenarios where status updates have to be continuously distributed. We propose a novel Parallel Sequential All-to-All Flooding (PSAA) protocol which is tailored to LVDGs and tries to minimize the average AoI. Special focus is given to the relation between AoI and retransmissions which are necessitated by unreliable communication channels. We show that PSAA is able to significantly outperform simple flooding schemes in characteristic LVDG topologies. Extensive simulation studies highlight the interaction between retransmission timer and AoI.