South East Substation to Snuggery Substation

Construction of a new 132kV transmission line from the Snuggery Substation to the South East Substation to enable the windfarm at Lake Bonney to export up to 240mW.

The customer

ElectraNet delivers safe, affordable and reliable solutions to power South Australian homes and businesses. Their transmission network is a crucial part of the electricity supply chain and is used to safely deliver electricity throughout South Australia including regional and remote areas. ElectraNet specialise in asset and project management, contract management and their clients include SA Power Networks, Enerven and large directly connected clients.

The opportunity

ElectraNet had a required to construct 43km of 132kV transmission line from the Snuggery Substation to the South East Substation to enable the windfarm at Lake Bonney to export up to 240mW

The solution

As part of this project, 43km of new line was installed from the Snuggery Substation to the South East Substation. With 252 stobie poles installed, weighing up to 21 tonnes each, over 3000 cubic metres of concrete was used for the footings.

Ground conditions in the South East were also a challenge with both rock and swamp encountered along the length, to ensure site safety an additonal 3km of access tracks were installed.

One of the main features of the project was the design and installation of a 3-way differential protection scheme to allow for the increased load generated by the windfarm.

The three sites involved were:

• Mayurra Substation - the customer connect substation for Lake Bonney Windfarm
• Snuggery Substation - one mesh bus circuit breaker replaced to accommodate single pole reclosing as well as line modification to accommodate the introduction of the South East line and the relocation of the Blanche line exit
• South East Substation - installation of an Operations Wide Area Network (OPSWAN) on connection of the Optical Ground Wire (OPGW).

The design also included a telecommunication component to ensure the scheme operated as intended.

Apart from the OPGW connection and terminations there was also a requirement for a new 13GHz radio system between Mount Burr and Mayurra - requiring a new pole structure to be constructed on a ridge outside the Mayurra substation at the Lake Bonney Wind Farm.

New multiplexer equipment was required at all three substations and included the installation of DN2 and DB2 loop protection functionality. Multiplexer work was also required at Mount Burr radio site and Tailem Bend Substation.