Optimal Coordination of Overcurrent Relay in IEEE 39 Bus System

Protection Relays and Circuit Breakers are the major devices for large interconnected power system. Proper protection is needed to isolate the faulted region from healthier network. When two protective Relays are installed in series with transmission line have certain features, which provide a specified operating sequence, they are said to be coordinated or selective. Relay coordination is an important portion in the protection system design as coordination schemes must be fast, selective, and reliable Relay operation. Learning and analysis of Relay coordination is performed to make sure that safety operation of the transmission system are functioning correctly and to avoid the unwanted tripping. The reason for unwanted tripping is variation in the Relay protection settings. In this project, Over current Relay is used for proper protection. The Relay protection is designed for IEEE 39 bus system using DIgSILENT and their coordination is achieved.