Development of a pole-mounted RTU for use on rural power lines

In rural areas in South Africa, the 33 kV and below power lines can cover long distances due to the low density of consumers. These networks form the final link in the chain of supply to customers. They are equipped with pole-mounted auto reclosers, sectionalizers, and air switches for fault protection and the sectionalising of lines when searching for faults. Faults on these lines can take many hours to investigate due to their large geographic area. Repairs are effected using traditional manual inspection techniques and operators in control centres initially have to rely on telephone calls from end users to identify approximate fault locations. This results in customer dissatisfaction, high cost of maintenance, and lost energy sales. In the late 1980s, Eskom formulated a long term vision that defined the end objectives in the implementation of a co-ordinated technology strategy. This paper describes a pole-mounted RTU SCADA system that was developed for monitoring and control purposes in line with this Eskom vision