Power Systems Relay Coordination using Hardware-in-the-loop

The reliability of a microgrid to a large extent is heavily influenced by the effectiveness of its protection system. Therefore, it is paramount to have a protection system that can effectively isolate components on the network in the presence of faults, achieving this with minimal disruption in continuity of service. There are various solutions that have been developed to support power engineers or students in testing and analyzing the reliability of a protection system network. Power Systems simulation software such as ETAP are widely utilized for this purpose and have proven beneficial to students in their understanding of faults and power protection systems. This research is focused on implementing a solution that is a step beyond software simulation, in that it enables students to easily test protection systems performance and learn about the impact of faults on microgrid networks. The physical 50kW microgrid test-bed at Penn State Harrisburg is implemented on the OPAL-RT real-time digital simulator. This simulator is configured to effectively communicate via MODBUS with other hardware components in the laboratory, such as relays and automation controllers. This hardware-in-the-loop configuration extends the capability of experiments performable on the physical 50kW test-bed. The emulated microgrid within the simulator is provided to students. Students are able to execute different kinds of faults on the microgrid network, easily program various relay configurations on the automation controller and test their performance by implementing faults on the microgrid. The impact of faults across all buses on the emulated microgrid is recorded and compared with results obtained from ETAP. The programmed relays' response time to these faults are also recorded and observed. This research offers an innovative approach for students to assess performance of a protection system, test different protection solutions, relay types, and analyzing impact of faults on a power system network.