Date of Graduation
Statler College of Engineering and Mineral Resources
Lane Department of Computer Science and Electrical Engineering
Muhammad A. Choudhry
David W. Graham
The electrical power simulator in Engineering Sciences Building (ESB) at WVU was dismantled in July 2018. The simulator was used as a teaching tool for EE students to conduct lab experiments. The power simulator employed electromechanical and microprocessor protection relays, manual isolation and industrial circuit breakers, switches, variable autotransformer (VARIAC), voltmeters and ammeters. During the dismantling, a lot of equipment was retrieved for future possible use. This led to the idea of designing and implementing a simple circuit on a test bench that can be used as a lab equipment to demonstrate the operation of overcurrent protection relays. It was decided to design the circuit so that it employs equipment removed from the power simulator including microprocessor-based SEL-751A Feeder Protection Relays, Westinghouse CO-8 electromechanical relays, variable autotransformer (VARIAC), voltmeter, ammeter, isolation circuit breaker, and a tripping circuit breaker. A circuit test bench, available in the lab, was modified for this purpose. The bench provides the advantage of having a setup on a small and movable platform.
The circuit of the Overcurrent Protection Relays Test Bench has a variable autotransformer with protection relays, protection breakers and changeover switches installed on the primary and secondary side of the transformer. SEL-751A or three electromechanical CO-8 relays, one on each phase, can be selected as the main protection device on both sides of the transformer. There was only one industrial circuit breaker available in the lab. This has been installed on the secondary side. For the primary side, a breaker circuit has been designed and used which uses general-purpose DPDT and electronic relays, DC power supply, voltage limiting resistors, toggle switch and push-button reset switch. This use of the breaker circuit has saved a lot of costs since most of the components used in the design were already available in the lab.
Based on the cost-effective design, it is planned to design a similar circuit that can demonstrate the operation of differential current protection relay based on SEL-387A Current Differential Relay.
Khattak, Khalid Daud, "Design and Implementation of Overcurrent Protection Relays Test Bench" (2019). Graduate Theses, Dissertations, and Problem Reports. 7468.