An educational aid for the study of overcurrent and earthfault protection

Abstract

The objectives of this dissertation are purely academic and aim at the generation of a number of aids for the understanding of time delayed overcurrent and eartfault relays as employed so as to obtain discrimination in fault clearance. The dissertation starts by giving a general overview of such systems then goes into explaining the operation of time delayed relays. Before ending in the design , construction and testing of an artificial line for the study of time and current discrimination as applied to fault clearance the project presents and analysis a procedure adopted to test relays in the laboratory. It is not the aim of this dissertation to go into complex fault calculations using sequence networks since they are of no use to the project