Design and Implementation of an over Current Protection Laboratory for Electrical Power Transmission Systems Based on PLC Techniques

Abstract

This paper describes a modern approach for the protection of transmission lines to ensure their safety against the faults occurred in power systems. Our approach uses a Programmable Logic Controller (PLC) to realize a transmission line as an over current protection relay. A conditioning circuit was designed, implemented and tested to collect data obtained from Hall Effect sensors which convert them to suitable analog values compatible with PLC's inputs. Results obtained by our PLC control system are very similar to those obtained by the conventional relays but more efficient. An Automatic Reclosing System (ARS) for remote faults is also included in this approach. Our PLC control system and its algorithm are illustrated in this paper also. This approach is designed to be used in electrical networks laboratories as an educational unit in electrical departments of engineering collages and technical institutes; it can be used also in real power systems through suitable interfacing facilities.