Functional structure for performance improvement of time overcurrent relays

In this article, we recommend a functional structure for time overcurrent relays. This type of relay has a higher sensitivity and reduced back-up times compared to other types of relay using only the information available at the relay's site. We describe the functional structure of time overcurrent adaptive relays for phase protection. The results obtained from time overcurrent adaptive relays are collated, and the results from analysis of negative sequence relays and conventional time overcurrent relays are also presented.