High Voltage testing of 66kV primary plant
Location: South Australia
Best Industry practice dictates that all HV assets should be condition-tested regularly to confirm their suitability to remain in service. Regular testing can also assist owners in the preparation of budgets for the replacement of the assets when they reach their end of life cycle.
STE were engaged to conduct the HV tests on the installed primary plant at a substation on a renewable energy site, which has been in operation since being connected to the transmission grid in 2015.
The following items of high voltage plant were nominated for testing:
- 33kV/66kV power transformer
- 66kV circuit breakers
- 66kV current transformers
- 66kV capacitive voltage transformers; and
- 66kV surge arrestors.
STE utilised the following company-owned test equipment to conduct the required tests, interpret the results obtained, and provide detailed reports and recommendations.
- Doble M4100 power apparatus and insulation test unit
- Doble M5000 Sweep Frequency Response Analyser
- Tettex Turns Ratio Tester
- Megger BM25 Insulation Tester
- Megger DLRO 600 Micro-ohmmeter; and
- AVO DC Winding Test Unit.
Any anomalies that were detected during the testing were relayed to the client immediately.
The team mobilised to the site on a Sunday, ready to commence the testing during a scheduled outage which started on the following Monday.
The mobilisation involved the crossing of state borders and due to the COVID-19 restrictions, required letters of approval for interstate travel.
The team travelled a distance of 870 km from the STE head office to the site, including regular breaks and frequent phone calls to management as per the STE fatigue management policy.
Upon completion of the testing, the client was debriefed on the findings before the team demobilised back to Adelaide. A detailed report was provided within ten working days.