Traffic Modeling and Evaluation of QoS schemes in Wide Area Monitoring System

Abstract: To prevent a power grid from having disturbances that may, in a worst case scenario, blackout entire countries, Transmission System Operators (TSO) want to be able to see what happens in different parts of the network faster, to have time to do the necessary changes and regulate the power grid. For this reason, a new technology called PMU-based Wide Area Monitoring System (WAMS) has been introduced to allow the real-time monitoring of the power grid. Due to having real-time information from many points in a large geographical area, the PMU technology allows the development of advanced applications to control, protect and monitor the entire power grid. The information gathered by the PMU is sent via a TCP/IP communication network to a PDC to be processed. The applications that use the PMU data have different requirements on that the data arrives within a certain time frame. As an IP network can only provide best effort service, the delay, jitter and packet loss can never be guaranteed which means that the PMU data can never be guaranteed to arrive in time with potentially serious consequences. This problem may be remedied by implementing different quality of service (QoS) schemes on the TCP/IP communication network to assure that the PMU data falls within its requirements. The purpose of this master thesis is to evaluate the different QoS schemes in a TCP/IP communication network dedicated for WAMS systems and the effect they have on the delay, jitter and packet loss on the different traffic flows. For this purpose, the typical TSO‟s TCP/IP traffic data and the communication network specifics have been studied and modeled using the simulator tool OPNET. The different scenarios‟ results have been collected and analyzed in regard to the different QoS schemes.