Enabling Hard Service Guarantees in Software-Defined Smart Grid Infrastructures

TL;DR

This paper presents an SDN-based approach for reliable, real-time communication in smart grids, ensuring hard service guarantees through fast failure recovery and delay-aware reconfiguration, validated on a Nordic test system.

Contribution

It introduces an SDN controller with embedded Network Calculus logic for delay guarantees and dynamic reconfiguration tailored for smart grid communication needs.

Findings

Hard service guarantees are achievable with the proposed SDN solution.

Delay bounds are maintained through NC-based supervision and reconfiguration.

Time-critical services are identified that require fixed configurations.

Abstract

Information and Communication Technology (ICT) infrastructures play a key role in the evolution from traditional power systems to Smart Grids. Increasingly fluctuating power flows, sparked by the transition towards sustainable energy generation, become a major issue for power grid stability. To deal with this challenge, future Smart Grids require precise monitoring and control, which in turn demand for reliable, real-time capable and cost-efficient communications. For this purpose, we propose applying Software-Defined Networking (SDN) to handle the manifold requirements of Smart Grid communications. To achieve reliability, our approach encompasses fast recovery after failures in the communication network and dynamic service-aware network (re-)configuration. Network Calculus (NC) logic is embedded into our SDN controller for meeting latency requirements imposed by the standard IEC 61850 of the International Electrotechnical Committee (IEC). Thus, routing provides delay-optimal paths under consideration of existing cross traffic. Also, continuous latency bound compliance is ensured by combining NC delay supervision with means of flexible reconfiguration. For evaluation we consider the well-known Nordic 32 test system, on which we map a corresponding communication network in both experiment and emulation. The described functionalities are validated, employing realistic IEC 61850 transmissions and distributed control traffic. Our results show that hard service guarantees can be ensured with the help of the proposed SDN solution. On this basis, we derive extremely time critical services, which must not be subjected to flexible reconfiguration.