Transgrid has published a Project Specification Consultation Report (PSCR) for Maintaining safe and reliable operation of Buronga substation. Publication of this PSCR represents the first step in the Regulatory Test for Transmission (RIT-T) process.
The X2 transmission line (from Buronga to Broken Hill) is a radial feed to Broken Hill substation so maintaining a reliable supply to the area when Line X2 is out of service requires significant planning and coordination with Broken Hill loads in addition to running the gas turbine generators to supply the Broken Hill 22 kV load.
During asset replacement planning of Buronga X2 feeder circuit breaker (CB), it was identified that the condition of the bus disconnector, line disconnector and bypass disconnector prevent outage access for the CB replacement. Due to the disconnector functional failure a X2 transmission line, outage is required to access the CB.
We have classified this RIT-T as a ‘market benefits’ driven RIT-T as the economic assessment is not being progressed specifically to meet a mandated reliability standard but by the net benefits that are expected to be generated for end-customers. Given the quantity of CBs that have been identified for replacement, Transgrid considers it prudent and cost effective to manage this risk through a single asset replacement program. This replacement will help limit the amount of in-service failures that occur (along with the associated interruptions to customer load, and safety and environmental consequences).
In the PSCR Transgrid presented three credible network options that would meet the identified need from a technical, commercial, and project delivery perspective. This PSCR finds that implementation of Option 3 is the preferred option at this draft stage of the RIT-T process. Option 3 involves replacement of identified assets with double bus selectable feeder bays.
The capital cost of this option is approximately $8.44 million (in $2024/25) +/- 25 per cent. Transgrid welcomes written submissions on materials contained in this PSCR. Submissions are due on 14 November 2024.
In accordance with the requirements of the Rules, a summary of the Project Specification Consultation Report is made available on the AEMO website. A copy of the PSCR can be obtained from Transgrid’s website or by emailing regulatory.consultation@transgrid.com.au.