Pilot Wire Protection Technique

Pilot Wire differential protection system is installed in the Power networks. In this system a pair of metallic cables is used for connecting the two relays located at both ends of a distribution line. This work studied ways to improve the reliability and stability of the pilot wire protection system by using duplication and diversification of the pilot wires. This work presents the calculations relating to design of duplication and diversification of existing pilot wire protection system in the Darwin area without using any new investment. It is found that duplication is possible in the whole Darwin pilot wire protection network but diversification is not possible in only a few routes because, no existing different pilot wire route is available. This work also presents some practical data and designs which has been tested. It proves that the pilot wire supervision scheme or overcurrent check features can¿t remove the Pilot Wire open circuited issues. But duplication and diversification can overcome those issues and can assure a more reliable and stable Protection System.