Quality-of-Service Considerations in Utility Communication Networks

This paper discusses the impact that communication will have on the electric power grid in the future. Recent efforts, such as UCA 2.0 and IEC 61850, are establishing a standard way for electric power substations, intelligent electronic devices, and other apparatus to communicate over data networks. These efforts pave the way to a future where protection and control of the electric power grid will migrate towards a common utility intranet. The intranet will almost certainly be based on Internet standards due to their widespread use, low cost, and easy migration path over time. A utility intranet, common to the utilities but separate from the Internet, will allow for the eventual connection of regional substations, equipment, and control centers throughout the grid. The transition will allow capabilities beyond what is currently available, but it requires a careful understanding of the implications for network capacity constraints, protocol selections, and quality-of-service technologies. This paper discusses the benefits of utility communication, the likely pitfalls in the use of Internet technology for protection and control systems, and technologies that can help to mitigate those pitfalls. This paper also introduces a model for the expected background traffic that will be present in a utility intranet. Experimental results illustrate the use of different communications protocols in representative power situations in the face of different levels of background traffic in the electric power and communication synchronizing simulator simulation environment.