Experimental study on overcurrent relay setting for maximum protection level

This paper addresses both the experimental and simulation studies on the application of overcurrent protective relay. The industrial overcurrent relays often have three individual settings. In this paper, the relay operating characteristics are set on normal inverse and very inverse curves. These curves operate as backup of each other. The third setting is also set on the instantaneous definite minimum time. The designated protection scheme protects the system with the least operating time.