Project: Transpower Pole 3 HVDC and Pole 2 Control replacement

Service: HVDC

Client: TransPower

Country: New Zealand

Year: 2009-2012


Transpower New Zealand recently built a new Pole 3, which is a point-to-point LCC HVDC link between their North and South Islands. They also replaced the existing pole 2 controls with new controls from the same vendor. TGS developed the technical specification for the HVDC converters. TGS also performed design review, witnessed factory acceptance tests and provided on-site support during commissioning.

TGS Owner’s Engineer services:

  • Specification Development
  • Review of HVDC manufacturer design reports
  • Witnessing factory performance testing (FPT)
    • Valve
    • Control & protection (Extensive functional performance tests)


The main challenges with the Transpower pole 3 project were:

  • An extensive amount of Factory performance testing was required to ensure minimal impact to the islands during testing.
  • Implementation of a round power mode to enable the link to stay online at 0MW power transfer
  • Weak system
  • Integrating a new pole while maintaining operation of the other pole which used a different vendor’s equipment.
  • Integrating controls from a different vendor to an existing valve.