Directlink interconnector

Directlink interconnector (also known as Terranora interconnector) is a 180 MW underground HVDC Light^® transmission link connecting the New South Wales and Queensland electrical grids in Australia, allowing power to be traded between the two states.

The 65-km long link was built by TransÉnergie Australia, a subsidiary of the Canadian utility Hydro Québec and Country Energy. TransÉnergie US supplied its technical expertise for the construction and operation of the interconnection, as well as its expertise in marketing transmission services. The transmission system is now owned by Energy Infrastructure Investments consortium and operated by the APA Group.

The Directlink interconnector comprises three HVDC Light^® independent links of 60 MVA each operating at 80 kV. Three pairs of underground polymeric insulated HVDC Light^® cables operate at ±80 kV and transmit 60 MW each, linking the regional electricity markets of New South Wales and Queensland.

The interconnection links the 132 kV AC grid in New South Wales with Queensland's 110 kV AC grid, and solves capacity shortage problem in southern Queensland, and a surplus capacity issue in New South Wales.

HVDC Light^® technology provides numerous advantages for power market projects like this, including mostly underground installation on existing rights of way, easing permit processes and reducing environmental impacts; precisely defined and controlled power flow that matches power need and/or controls network voltage; support for weak power networks connected to the link; modularity, standardized design reducing construction and commissioning periods – the Directlink interconnector HVDC Light^® link was delivered in 12 months.

These features mean that HVDC Light^® facilities can be installed quickly in response to competitive market signals.