Department - Author 1

Electrical Engineering Department

Degree Name - Author 1

BS in Electrical Engineering



Primary Advisor

Ali O. Shaban


The objective of this senior project is to protect a three terminal transmission line during fault conditions using the SEL-311L microprocessor based relay and communication assisted permissive over-reaching transfer trip protection (POTT). The SEL-311L’s directional distance elements are programmed to trip on internal faults while faults external to the zones of protection are ignored. Upon sensing a fault condition, the relay issues a trip command to the local breaker and a permissive key for tripping to the remote relay via fiber optic communication. When a permissive key is received and all other permissive conditions have been satisfied, the remote relay issues a trip command to its breaker. Included in this senior project are lab materials for students who wish to complete the lab or for integration into a power protection laboratory in the future. The lab introduces Over-reach concepts and Zone 2 protection. Students gain experience in programming SEL relays, testing protection functionality, and protective relay logic.