Meridian plans control system upgrade

New Zealand generator Meridian Energy is planning a sweeping upgrade to the computer control system responsible for managing 30 percent of the country's power supply.

Meridian's existing control system, which has been largely developed internally, manages the company's nine hydro-power stations in New Zealand's South Island. The energy company also operates an off-site backup to its main control room at Twizel, but a third backup centre is planned.

Meridian is set to replace the Supervisory Control and Data Acquisition (SCADA), and Energy Management Systems (EMS) parts of the legacy platform, which according to spokesman Alan Seay were becoming outdated.

The new control system will allow up to 50 concurrent users to work from any of Meridian's locations, while its database is expected be capable of supporting a quadrupling of the company's present generation capability.

A recent request for information indicated that the updated control system will bolster Meridian's security of electricity supply. The security of electricity supply has become a thorny political issue in New Zealand after a spate of outages in recent years, the worst of which left Auckland's central business district without power for five weeks in 1998.

The new control system will feature a distributed architecture in order to be resilient to network failures of any single component with minimum disruption. As a result, each hydro-generating station is capable of operating locally if isolated from the central control system.