Bluegrass BESS: HV Testing and Commissioning

The Bluegrass BESS, also known locally as the Chinchilla 60 MW BESS, is a 60 MW / 120 MWh grid-scale battery energy storage system located in the Western Downs region of Queensland, approximately 14 km from Chinchilla. Built as Stage 1 of a 148 MW hybrid addition to the operating 200 MW Blue Grass Solar Farm, the project connects into the 132 kV Chinchilla to Columboola transmission line on the Powerlink network. The asset uses Narada Power batteries and Ingeteam power conversion systems, and forms part of the ARENA-supported program to deploy advanced inverter capability, providing inertia and voltage support into the Queensland grid.

Megavar was engaged by ACLE, the head contractor, to deliver the high-voltage testing and commissioning scope across the project's 33 kV plant. The scope spanned Factory Acceptance Testing, Site Acceptance Testing, protection systems commissioning, HV cable testing, HV switchboard testing, and earth testing, carried out between May 2025 and February 2026. The work covered eight 33 kV feeder bays, a 33 kV incomer, a 750 kVA auxiliary transformer kiosk, and the supporting 125 Vdc auxiliary systems.

Delivering a grid-forming BESS in a remote location, inside an operating solar farm, required close coordination with ACLE's construction programme and a testing approach that could move in stages as scope was progressively released. The Megavar team combined experienced site-based testers with remote engineering support to keep the job moving at the pace ACLE required.

• 2 x 33 kV ABB ZX2 switchboard panels (1 FAT, 1 SAT)
• 2 x 33 kV Siemens 8DA10 switchboard panels (FAT)
• 6 x 33 kV Siemens 8DA10 switchboard panels (SAT)
• 1 x 750 kVA auxiliary transformer kiosk
• 125 Vdc battery bank, chargers and DC distribution board

Megavar applied its in-house Omicron-led test fleet across the full testing and commissioning cycle:

• Omicron CMC 356 protection relay test sets with CMGPS 588 satellite-synchronised end-to-end testing units
• Omicron CPC 100 multi-function primary test systems
• Omicron CIBANO 500 circuit breaker analyser and Megger MOM3 micro-ohmmeter
• Omicron CT Analyzer for current transformer performance testing
• Omicron Testrano 600 for transformer testing at the 750 kVA kiosk
• HV Diagnostics HVA60 VLF set for 33 kV cable withstand testing and Phenix PFT-503 50 kV AC hipot for HV withstand testing
• Megger HSW3-2 high-current source and Megger 5 kV insulation testers
• Megger Torkel 930 for 125 Vdc battery bank capacity verification

Standards and Compliance: Testing and commissioning was performed to the relevant Australian Standards and to the project-specific Blue Grass BESS Protection Report, and to ACLE's approved Inspection and Test Plans. All test records and commissioning certificates were issued against ACLE's ITP framework.

Megavar completed the testing and commissioning scope in line with ACLE's programme, and the following 33 kV assets were successfully energised following completion of the testing and commissioning work:

• 2 x 33 kV feeders (B01 and B02), extended onto the existing bus in the Blue Grass Solar Farm 33 kV switchroom
• 1 x 33 kV incomer (EB13) in the new Blue Grass BESS Switch Room 1
• 6 x 33 kV feeders (EB11, EB12, EB14, EB15, EB16 and EB17) in the new Blue Grass BESS Switch Room 1
• 1 x 750 kVA auxiliary transformer kiosk
• All works were delivered in line with the project's Australian safety and quality standards and to the ACLE-approved ITP framework.