Upgrading and replacement of GE SCMS, TAQA Transmission

About this project

TRANSCO project N-15223 replaced the substation control and monitoring system across six grid stations, delivered by Almafor as main contractor. The systems being retired were of Alstom and GE manufacture and had passed the point where they could be supported.

The six stations span the full range of the transmission network: a 400 kV to 220 kV station, a 400 kV station, a 220 kV to 33 kV station, and three stations at 132 kV to 11 kV. Each one is a separate cutover with its own outage constraints, which is why the programme ran over several years rather than as a single installation.

Each station received SCMS servers, human machine interface and engineering workstations, IEC 101 gateways, bay control units, fibre optic cabling and a station UPS rated 5 or 6 kVA. The operator and engineering positions were kept on separate machines, because the position that runs a live network and the position that changes its configuration should not be the same keyboard.

Integration reached beyond each station. The systems were connected to the Load Dispatch Centre, the Emergency Control Centre and the Distribution Management System, so that a station is not only locally automated but visible and controllable from the places that actually dispatch the network.

None of this happened on dead plant. Transmission service was maintained throughout, station by station and bay by bay, with each new controller proven against the existing interlocking before anything was transferred to it. The trigger for the whole programme was not failure. It was unsupportability: the platforms still worked, and the spares, the software and the people who understood them had gone.