Several tests according to IEC 60076 Standards were performed in May 2022 on a three-phase oil-immersed auto power transformer 250 MVA 400 / 155 kV at GETRA factory placed in Caserta (Italy) by LCOE technicians.

LCOE measurement equipment, including instrument transformers, power analyser and sound-meter, were displaced to GETRA factory to perform on-site the following tests according to IEC 60076-1 and IEC 60076-10 Standards.

• Measurement of windings resistance at ambient temperature.

• Measurement of no-load losses at several voltage levels up to 170.5 kV.

• Measurement of load losses at rated current 361 A for rated tap 155 kV, minimum tap 142.6 kV and maximum tap 167.4 kV and calculation of load losses at reference temperature 75 ºC.

• Measurement of total electrical power of the OFAF cooling system for PEI calculation, including several air fans and oil pumps.

• Determination of sound power level at rated voltage according to IEC 60076-10 Standard by using weighted sound pressure method.

250 MVA 400 kV Power Transformer. Determination of sound levels.

Generation system of the factory was used to apply the required test voltages and currents to carry out the tests and the LCOE test results were compared with the measurements of the manufacturer.

All tests were witnessed by TERNA, final customer and user of the auto power transformer for the Italian high voltage grid, and the presence of LCOE, as an independent entity, was required to verify the rated characteristics of the transformer and compliance with TERNA technical specification.

More information: Tomás García tgarcia@ffii.es