Life extension of the New Zealand HVDC link

The New Zealand HVDC link is one of the two oldest HVDC links that is still running with original installed equipment from 1965. The New Zealand HVDC link was upgraded and modernized in 1992 when a new thyristor pole was added, the line voltage was raised, new cables added and the original mercury arc poles were equipped with new control equipment and rearranged to operate in parallel on one pole. This report describes briefly the original link, the upgrade in 1992, the life-extension initiatives that have been completed to date, and some future options.