TGOOD Au / OZ Minerals

OZ Minerals 132kV Substation Upgrade

OZ Minerals required the expansion of the substation at Prominent Hill mine site. The expansion consisted of an additional 45MVA 132/11kV transformer and associated HV infrastructure and switchgear, an additional 11kV switchroom, an additional LV control room, two new site 11/0.4kV transformers and two 11kV STATCOMs.

GPA were engaged by TGOOD AU on behalf of OZ Minerals to provide detailed design and engineering services for the following:

  • Civil/structural design for all new infrastructure
  • HV design for the expansion of existing 132kV busbar system including the addition of a new 132kV disconnector
  • 132kV hybrid GIS circuit breaker 132/11kV Transformer

GPA were also responsible for designing the new protection, secondary, SCADA and CITECT systems required for the new plant and equipment, as well as incorporating this into the existing substation systems.

OZ Minerals Prominent Hill (PH) Mine was previously powered from a 132kV Over Head Line (OHL) from BHP’s Olympic Dam (OD).

As part of the power supply project initiated by OZ Minerals, a new long distance 132kV OHL was built by ElectraNet from Mount Gunson South Substation to intercept the existing OD-PH 132kV line approximately 170km from Prominent Hill Mine. At the intersection of existing and new transmission line towers, the existing line to Olympic Dam was disconnected and the new overland line connected to the remainder of the existing line to Prominent Hill.

The project involved a significant construction phase for a long transmission line through a very remote area, and engineering design sufficient to meet the electrical protection, stability and communications requirements of such a large power demand at the end of a long transmission line. GPA were involved in the discussions and a design interface with ElectraNet for the protection and automation interface with the transmission line.

GPA worked with ElectraNet to detail how the transmission line protections would interface to the substation, and reviewed the line protection scheme coordinating with the existing and new assets to confirm the line protection operate the three 132kV circuit breakers and effectively grade with the local substation protection.

The upgraded substation is subjected to a Customer Performance Specification (CPS) – a stipulation of ElectraNet under the AEMO requirements. A key responsibility under GPA’s scope was ensuring that the status and measurements for key Prominent Hill assets required to be monitored by ElectraNet were collected in a local data concentrator and passed on through the transmission line communications link.

Under the project GPA personnel were involved in commissioning the data concentrator onsite and worked with ElectraNet to confirm that all data required was available on this link.

GPA contributed to the successful energization of the Prominent Hill 132kV Hill 2 Hill project – the longest 132kV line in the world with a large crushing and milling machine at the end of line.