Many of TransGrid’s substation and transmission line assets were built in the 1950s and 1960s and are now approaching the end of their serviceable lives. As a result, a progressive replacement or refurbishment of these assets across New South Wales is currently underway, which will give them all a new lease of life.
TransGrid recently proposed to increase expenditure on the replacement of existing assets by around 40 per cent from current levels, in light of many of these assets requiring renewal and replacement due to their age and condition.
“Given the large number of assets that were constructed during the initial establishment of the transmission network, this has resulted in an increase in the number of TransGrid assets including substations and their equipment, now requiring replacement or renewal over the next five years,” said TransGrid’s Executive General Manager of Network Planning and Performance, Stephen Clark.
TransGrid’s asset renewal program is based on the organisation’s asset renewal system, which has been independently reviewed against newly released international standard ISO55001 (for more information on the standard, see A new standard in asset management, page 34). As a result TransGrid expects to attain full certification to ensure it continues to achieve international best practice standards in asset management.
“This program is essential to ensure the ongoing safety of staff, contractors and the public, and to maintain the reliable supply of electricity to New South Wales,” Mr Clark added.
When TransGrid performs a condition assessment on a substation asset, a range of indicators are used to determine whether renewal or replacement works are required.
“All of our asset renewals are based on condition. The age of the asset is just one indicator which we look at. Age points us in the direction of doing a full scale condition assessment,” said TransGrid Asset Manager Garrie Chubb.
“TransGrid looks at the environment in which the substation is located, its initial design, maintenance history, defects, service performance and any replacements that may have previously occurred at the site.”
Once a condition assessment has been completed, TransGrid identifies the scale of the works required. Possible options include a whole scale renewal, targeted renewal or just a component type replacement of the substation and its equipment.
Upcoming renewal projects
Yanco Substation renewal
The Yanco 132kV Substation was commissioned in 1969 and supplies Essential Energy’s Narrandera Zone Substation at 66kV and several local 33kV feeders. A large majority of the substation’s equipment is reaching the end of its serviceable life and will be replaced in order to maintain reliability of supply. The refurbishment of the substation is expected to be completed by late 2015.
The in-situ renewal of the Yanco substation will involve the replacement of the primary and secondary systems and the:
•Replacement of four 132kV circuit breakers
•Decommissioning of twelve current transformers
•Demolition and removal of the 132/33kV transformer, auxiliary transformer, associated switchbays and transformer compound
•Augmentation of communication facilities.
Cooma Substation replacement
The Cooma 132kV Substation was established in 1954 and supplies the 132kV lines to Bega and Snowy Adit/Munyang, as well as supplying electricity to the Cooma township, alpine region and New South Wales far south coast. The substation is supplied by two 132kV lines from the Canberra and Williamsdale area. All components of the existing substation are reaching the end of their serviceable life and a complete replacement is required.
Due to existing site constraints, the rebuild of the substation could not be completed in-situ and an alternative site, adjacent to the existing substation, was selected. Construction at the new site has commenced with the project expected to be completed in 2016.
The establishment of the new 132kV substation will comprise of the following components:
•Rearrangement of the existing 132kV transmission lines to connect to the new substation site
•Construction of a communications facility within the switchyard
•Construction of a permanent access road from the Monaro Highway to the substation
•Visual screening and landscaping works
•Decommissioning of TransGrid plant and equipment at the existing Cooma Substation site
Vales Point Substation rebuild
The Vales Point 330kV Substation connects Vales Point power station into the electricity supply grid and supplies the local Ausgrid load at 132kV. The rebuild of the substation involves a staged in-situ rebuild of the 330kV and 132kV switchyards. This will include the replacement of some substation equipment and associated infrastructure improvements, with existing equipment that is in serviceable condition to be retained. The project is expected to commence mid 2015 with works to be completed by late 2017. The key features of the rebuild will include:
•Replacement of equipment and the secondary systems within the 330kV switchyard
•Removal of the double breaker bays within the 330kV switchyard
•Rebuilding of the double breaker bays within the spare bays and 330kV tie transformer switchbays
•Refurbishing the relay buildings and installing secondary systems for the 330kV and 132kV switchyards
•Replacement of equipment and the secondary systems within the communications building
•Removal of two transmission towers
•Installation of a single transmission tower to reconnect lines into the relocated double breaker bays.
Tamworth Substation rebuild
The Tamworth 132kV Substation was constructed in 1961 and currently supplies the Tamworth area loads with nine feeders at 66kV to Essential Energy. It sources supply from another substation located in Tamworth (330kV substation) through two short 132kV lines. The existing 132kV substation has reached the end of its serviceable life and a complete replacement is required. The construction of the new substation will be within the current footprint of the existing substation site. Construction has commenced and works are expected to be completed in 2017.
The scope of this project includes:
•Construction of a new 132kV substation to replace the existing
•Construction of a 132kV bus section breaker bay at Tamworth 330kV Substation
•Rearrangement of existing 132kV lines to establish two 132kV connections between the Tamworth 330kV Substation and the new Tamworth 132kV Substation
•Cutover of 66kV lines to the new 132kV substation
•Provision of secondary systems suitable for the staging of works and the final arrangement.
TransGrid – what we do
TransGrid has been an integral part of delivering electricity to the people of New South Wales (NSW) for more than 60 years.
It owns and operates one of the largest high-voltage transmission networks in Australia, up to 12,800km of transmission line and more than 90 substations, connecting generators. distributors and major end-users in NSW and the ACT. It also has links to Queensland and Victoria, facilitating interstate energy trading. Its operations are closely regulated to ensure power system security and TransGrid’s aim is to provide a safe, reliable, efficient and world-class electricity supply from power generators to distributors, which then deliver the electricity to homes across the state.