Mixing Real Time Ethernet traffic on the IEC 61850 Process bus

The introduction of the IEC 61850 standard represents a milestone for the Substation Automation System (SAS): the network based control system simplifies the architecture, increasing the interoperability and decreasing the development cost. Looking at the network structure, IEC 61850 defines the Process bus that is used to connect the equipment and sensors which operate close to the power lines. This paper investigates the case in which the Process Bus is opened to other real-time systems that use Real-Time Ethernet protocols. A simulation environment has been used to analyze the Process bus behavior when non IEC 61850 devices are connected (in particular, PROFINET IO devices). The preliminary results suggest the possibility to mix different real-time data streams on the Process Bus, with tolerable variations of the performance of the IEC 61850 applications.