Hitachi Energy's predecessor ASEA’s high-voltage direct current (HVDC) pioneering technology came to New Zealand in the 1960s. It was a key part of the ±250kV, 600 MW HVDC Interisland Link between Benmore (in the South Island) and Haywards (in the North Island) and was commissioned in 1965. It was originally a bipolar 600-megawatt (MW) link with mercury arc valves. This was just the third link of its kind in the world operating at voltage and current levels significantly higher than previously been attempted.
In 1992, the national grid owner, Transpower, further upgraded the original HVDC link so that it became paralleled onto a single pole (Pole 2). ABB was contracted to build the new converter stations for this project and also supplied and laid the new submarine cables across the Cook Strait. The new thyristor-based HVDC Pole 2 was commissioned and operated alongside the ASEA link, increasing capacity to 1040 MW. The original link was decommissioned in 2012 after 47 years in operation.
In 2018, Transpower upgraded its Pole 2 HVDC link with the latest control system technology. ABB was contracted to provide the system and commission the new control system in March 2020.
Hitachi Energy retains the HVDC technology as a core part of its world-class solutions that deliver on the promise of a sustainable energy future.