Short Circuit Analysis Tool Using 3rd Generation (3G) Mobile Technology

On the UK Rail Network, West Coast Main Line, a programme is in place to standardise the electrical feeder protection relays for the overhead electrification. Part of that standardisation has included the provision of remote post fault data extraction facilities which could be initiated centrally by users over the internet, set to interrogate the relays over feeder station analogue telephone lines, uploading that data into a central database, rendering the same via a web application for post incident analysis. This system is known as "SCAT" (short circuit analysis tool) and supplements the SCADA systems. Following the upgrade of part of the West Coast Main line overhead electrification system from booster transformer to an autotransformer system, a need arose to improve the reliability of communications between the central database and the feeder stations. The analogue telephone lines were proving to be troublesome at certain locations and the standardised feeder protection relays needed to be "on line" for longer in order to upload their more "rich" fault data. This has necessitated an upgrade to the SCAT system and two requirements arose from this, namely: 1) More robust data communications at troublesome sites based on inexpensive technologies. 2) An upgrade to the SCAT system to accommodate the standardised feeder protection relays. This paper discusses the technical challenges faced in the implementation of a "fit and forget" remote mobile data acquisition system and the realisation that a relatively inexpensive remote condition monitoring system had been created in the process.