Latency and Traffic Reduction for Process-Level Network in Smart Substation Based on High-Availability Seamless Redundancy

Process-level communication network brings digital technology to the high-voltage switchyard, a major stage in the evolution to ensure the protection control and data acquisition of smart substation. This network requires a mission-critical protocol such as high-availability seamless redundancy (HSR). Two main drawbacks of HSR, however, are the transmission latency introduced by each hop in the single ring (SR) topology and the unnecessary traffic due to the duplicated copies of sending frames. This study presents two enhanced solutions and fully implements quick removing (QR) approach to HSR for improving the latency and reducing the traffic volume in process-level network. The main idea of these two enhanced solutions is to reduce the minimum number of hops required for delivery messages to destinations for reducing the maximum end-to-end latency (ML). To achieve traffic reduction, the QR approach is concretized in HSR nodes for fully applying to any closed-loop HSR networks. Performance of IEC 61850-based process bus networks are analyzed theoretically and demonstratively by Network Simulator-2 (NS-2) and OPNET Modeler®. The combination of enhanced solutions and the QR algorithm solves both main drawbacks of HSR, improving the network performance optimally. These enhancements of HSR are applicable to not only on substation automation networks, but also to any real-time industrial networks.