Propagation and interaction of Ethernet packets with IEC 61850 sampled values in power utility communication networks

The different protocols offered by IEC 61850 can be transmitted over a common communication network for transporting traffic of different kinds from multiple senders to multiple receivers instead of using multiple point-to-point connections. There have been always concerns what might happen if high traffic load occurs on such a network, especially when many components of a power utility automation system initiate a data transfer because of an event in the electrical power system. Many of the concerns originated from network arbitration and congestion problems that occurred in the early days of the Ethernet, which are much less an issue with today's switched Ethernet networks. As long as only client/server and GOOSE (Generic Object-Oriented Substation Events) traffic are present on the network, there are no real challenges because the network load is relatively low, but when sampled values become involved, high packet rates and sustained network load occur. The real-time traffic must arrive timely at the subscriber. Delays and jitter become an issue.