Improving supply reliability for Southern Electric's rural customers

Market research carried out on behalf of Southern Electric has shown that customers find short duration interruptions, typically less than half a minute, just as inconvenient as longer ones. The decision was taken to improve reliability for rural customers and to make key sections of the overhead network as reliable as the underground ones. The majority, around 75%, of 'customer minutes lost' occur as a result of faults on the 11 kV overhead network. After surveying a sample of lines the decision was taken to rebuild the worst performing with insulated conductor. This would address all the causes apart from lightning and therefore significantly improve customer service. The author discusses this rebuilding programme.