Data Models and Protocol Mapping for Reduced Communication Load in Substation Automation with High Sampling Rate Protection Applications

In digital substations measurements between instrument transformers and protection systems are exchanged via an Ethernet-based process-level network using the Sampled Value (SV) protocol. At the same time, new protection applications, based on time-domain or travelling-wave signal information, require very high sampling rates, which increases the communication load on the network significantly. The increase of the communication load can be reduced through the concept of Distributed Signal Processing Units (DSPU). This paper proposes data models and suitable protocol mappings for such DSPUs and analyses their impact on the process-level network. The results are compared with the SV approach specified in IEC 61869-9 for digital interfaces of instrument transformers. It is shown that the DSPU concept can reduce the required network bandwidth in the case of high sampling rate protection applications.