McNeill Back-to-Back Converter Station Refurbishment

Commissioned in 1989, the McNeill station is a 150 megawatt (MW) back-to-back high voltage direct current (HVDC) link with converter station, interconnecting the asynchronous Alberta and Saskatchewan systems. 

Owned and operated by ATCO, the McNeill facility is the only electrical tie between the two systems in Canada, providing standby voltage support capacity in both alternating current (AC) systems, as well as energy exchange using thyristors.

ATCO replaced the original analog control and protection system with a newer digital system in 2015. The original high voltage direct current (HVDC) control system had reached the end of its life and, though still reliable, the decision was made to upgrade to avoid future difficulty in sourcing obsolete components in the event of a failure, as well as technical support to troubleshoot failures in outdated technology. 

To ensure the facility?s continued operation, ATCO upgraded the control system to a newer Alstom Series V under a turnkey contract, successfully integrating modern technology with an older facility.

ATCO was the owner?s engineer for this project and worked closely with the HVDC control system supplier to resolve all issues on a technical and contractual level to deliver an improved HVDC facility with its life extended, serving its role in the Alberta AC system for years to come.