A distributed Energy Management System consists of networked hardware and software capable of monitoring and controlling the operations of an electric utility. When several of these distributed systems are connected to each other via Wide Area Network connections, then a truly geographically distributed environment exists where data between systems can be shared. Heavy communication network loads and transit time constraints on these large amounts of shared data are significant design considerations, especially in light of the fact that most power utilities have existing private networks or use leased voice grade circuits. Modeling of the Wide Area Network aspects of interconnected Energy Management Systems was seen as a way to identify potential communications problem areas between systems early in the design process. Modeling would also help verify that the hardware and software designs would accommodate the communications load and ensure that transit times were within the system's functional requirements. System stress case data was used in each model to simulate a worst-case data acquisition and dissemination environment. This paper describes the modeled configuration and provides specific details about the system simulation techniques used and the conclusions provided by the model to estimate transit times and line rates for WAN connections.
