Fault location system for radial MV underground distribution cable networks

This paper presents a new fault localization system that utilizes the relays in the distribution cable networks that are equipped with the cable fault detection function. The cable fault is characterized with a short pulse and is self-clearing, therefore it is difficult to pinpoint the fault location. When a cable fault occurs on the networks, there could be a few relays to recognize the fault, but extra effort based on the network topology may be required to determine the faulty branch. The proposed fault localization system is comprised of three tiers, from bottom up, local, neighborhood and central. The proposed system assumes all the relays communicate through the Generic Object Oriented Substation Events (GOOSE) messages to its master processing unit which can be a protection relay or a separate industrial computer in its highest hierarchy in a tier. The proposed fault location system does not require adding any extra device or modifying any existing topology, and it only needs the necessary logic to the master processing unit. The system can be easily implemented or added onto the existing protection system that is able to receive the GOOSE message and is allowed to expand through some user programmable approach. The system communications among the components involved use the IEC61850 GOOSE Protocol, and it is easily scaled up or down depending on the application needs. The system, in particular, is suitable for the Medium Voltage (MV) power distribution networks in petrochemical, pharmaceutical, university, hospital, airport, data center, and other large manufacturing compounds.