Terna, owner and operator of the high voltage Italian transmission network, as part of their network development to connect new sources of renewable energy will be installing 400 MVA, 400/155 kV transformers to collect the generated power in different windfarms.
Short circuit tests subject the transformer to a real short circuit under the worst case conditions of the transmission network in terms of feeding power and efforts. This is a special test that utilities demand occasionally to validate the transformer performance to short circuits and the overall quality of the design and manufacturing looking for service reliability and continuity of the supply.
Terna's engineering management is committed to that purpose requiring short circuit tests in the first unit of a series.
During these tests, the active part of the transformer must withstand the extreme currents and forces caused by the short circuit conditions. It is estimated that the forces the winding see during the short circuit event is greater than the weight of more than 100 vehicles.
The validation process involves transformer manufacturing, factory audits and transfer to a special laboratory, in this case KEMA in Netherlands where the short circuit test is carried out. The transformer is finally shipped back to the factory for final verification tests and inspections.
The transformer, the largest 400 kV unit short circuit tested by ABB, successfully passed the demanding test requirements from IEC 60075-5 standard as required by Terna technical specification.
This ABB transformer will be installed in Spinazzola substation in southern Italy and it is getting ready to prove the performance in service.
