Trafo Elettro supplied n.2 oil immersed transformers 12MVA to a hydroelectric power plant near Ringerike municipality, Buskerud county, Norway.

This power plant produces 115 GWh annually with a reduction of CO2 emissions of 74 tons.

Transformers have the following technical characteristics:

Power: 12000kVA
Primary voltage volt: 22000
Secondary voltage at no load volt: 7400
Vector group: YNd5
Corrosivity category: C4-M

Transformers have been subjected to all type tests, in particular the heating test, the case pressure test and measurement of permanent deformation, the frequency response test (SFRA) and the DIRANA test which analyses and determines the water content and the oil conductivity in different types of cellulose insulation.

DIRANA uses dielectric frequency response (DFR) analysis in order to determine the condition of high-voltage insulation systems such as those in power transformers, bushings, cables and generators and connected to own software that automatically generates test plans based on the nameplate data. The measurement results obtained are automatically compared and evaluated according to international standards or customized limit values.

The customer followed all routine and special tests remotely and he was satisfied with the seriousness and technical skills.

Trafo Elettro invests daily in research and development using the latest generation equipment in order to guarantee a product of excellent quality.