Hardware digital protection

Abstract

The design and construction of prototype hardware – oriented digital overcurrent relay is presented. This newly designed digital relay is available to provide virtually all the functions traditionally associated with the existing relays for the protection of power systems and circuits against overcurrents and faults. Experimental results on a laboratory model are presented beside the time-current characteristics of different relay models. Test performance of the digital overcurrent relay shows that such a device is feasible and offers some distinct advantages over existing devices. By various adjustments, such a unit can operate as an Inverse, Very Inverse, Extremely inverse, Short-time, Long-time, and Definite-time Overcurrent relays.