Directlink (Terranora) Interconnector is a buried 59 kilometre (37 mi)
High Voltage Direct Current
A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curre ...
(HVDC) electricity transmission cable route from near Lavertys Gap (), Southwest of
Mullumbimby, New South Wales
Mullumbimby is an Australian town in the Byron Shire in the Northern Rivers region of New South Wales. It promotes itself as "The Biggest Little Town in Australia". The town lies at the foot of Mount Chincogan in the Brunswick Valley about 9 k ...
and Bungalora () & connected via a 3.5km (2.2mi)
AC Overhead Transmission Line to the NorthEast to the
Terranora Electrical Substation () @
Terranora, New South Wales New South Wales in Eastern
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
.
It is one of the two interconnections used to trade electricity between
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
and
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, established_ ...
(the other is the 330KV Dual Circuit
Queensland – New South Wales Interconnector
The Queensland – New South Wales Interconnector (QNI) is a 330 kV AC interconnection between New South Wales and Queensland, Australia.
The link was commissioned in 2001. It consisted of double-circuit 330 kV lines between Armidale, ...
(QNI)).
[
]
History
The interconnector was developed by a joint venture of NorthPower (later Country Energy
Country Energy, an Australian energy retail subsidiary of Origin Energy, provides natural gas and electricity to retail customers in New South Wales, Victoria, Queensland, South Australia and the Australian Capital Territory.. Since its establish ...
), TransÉnergie–a subsidiary of Hydro-Québec
Hydro-Québec is a public utility that manages the generation, transmission and distribution of electricity in the Canadian province of Quebec, as well as the export of power to portions of the Northeast United States.
It was established by the ...
, and ''Fonds de solidarité FTQ
The largest development capital network in the province, the Fonds de solidarité FTQ was created on the initiative of the FTQ, Québec's largest central labour body.
As of Novembre 30, 2022, the Fonds held $17.8 billion in net assets and ha ...
''.[
] The motivation to build the interconnector was the power shortage in Southern Queensland and surplus capacities in New South Wales. It was developed as an Independent Transmission Project.[ It was commissioned in December 1999 and it started operations in April 2000.][
][
] It was the first time that transmission systems of New South Wales and Queensland were linked.[
] The construction cost US$70 million.[
]
In December 2006, it was announced that Directlink would be purchased by Australian Pipeline Trust (APT, a part of APA Group APA Group may refer to:
* APA Group (Australia), natural gas pipeline and electricity company
* APA Group (Japan), a hotel group
See also
* APA (disambiguation)
{{disambiguation ...
) for US$133 million.[ The transaction was completed in February 2007.][
]
Originally, the interconnector operated as a non-regulated market network service. However, on 6 May 2004 an application to convert it to a regulated network service was submitted. The application was approved by the Australian Energy Regulator
The Australian Energy Regulator (AER) is the regulator of the wholesale electricity and gas markets in Australia. It is part of the Australian Competition & Consumer Commission and enforces the rules established by the Australian Energy Market C ...
on 10 March 2006.[
]
In December 2008, ownership of Directlink (as well as Murraylink
Murraylink is an Australian high voltage direct current electricity transmission link between Berri in South Australia and Red Cliffs in Victoria, connecting the two state electricity grids. Murraylink was commissioned in 2002 and is believed to ...
) was transferred to the Energy Infrastructure Investments Group, while the APA Group continued as the operator.[
] The ownership of EII is allocated as APA with 19.9%, Japan-based Marubeni
(, OSE: 8002, NSE: 8002) is a ''sōgō shōsha'' (general trading company) headquartered in Nihonbashi, Chuo, Tokyo, Japan. It is one of the largest ''sogo shosha'' and has leading market shares in cereal and paper pulp trading as well as a st ...
Corporation with 49.9%, and Osaka Gas with 30.2%.
Technical description
Directlink (Terranora) interconnector is a HVDC land cable route. The system has three 65MVA Voltage Source Converters at each station connected by three pairs of transmission cables. Each pair of cables operates at +/-80 kV and transmits 60 MW. In New South Wales it is connected to a 132 kV alternating current
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...
transmission grid and in Queensland to 110 kV alternating current transmission grid.[
]
The total rating of the interconnector is 180 MW.[
] The maximum net transfer minus losses is around 170 MW. If one pair of cables malfunctions, the available capacity is around 115 MW. If two pairs of cables are out of service, the capacity is around 57 MW.[
] However, in some cases for a limited time period the interconnector has operated in an overloading mode for up to 250 MW. The limiting factor for flow in the New South Wales direction is the thermal ratings of the Terranora–Mudgeeraba 110 kV lines and Mullumbimby–Dunoon 132 kV lines, and for flow in the Queensland direction is the thermal ratings of the Lismore–Dunoon 132 kV lines.[
]
HVDC VSC was chosen for this project for reasons of low environmental impact of the transmission route and the ability of the IGBT
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch, which, as it was developed, came to combine high efficiency and fast switching. It consists of four alternating lay ...
converter stations at each end to accurately control both real and reactive power. Individual water-cooled IGBT
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch, which, as it was developed, came to combine high efficiency and fast switching. It consists of four alternating lay ...
modules are rated at 2.5 kV and 500 A, with multiple units connected in series to achieve the required voltage rating.
References
{{Reflist
2000 establishments in Australia
HVDC transmission lines
Electric power transmission systems in Australia
Hydro-Québec
Electric power infrastructure in New South Wales
Electric power infrastructure in Queensland
Energy infrastructure completed in 2000