Microprocessor operated restoration of supply equipment

The author describes the application by Eastern Electricity of a microprocessor controller to restore supply automatically following a fault on a single-circuit 33 kV system near St. Albans. The automatic sequence was required to avoid the very high cost of a duplicate circuit which would otherwise have been necessary. A microprocessor controller was preferred to a conventional electromagnetic relay system because it allowed future alterations to be made without any rewiring and it would be possible to add sophistication to the restoration operations as the need arose