DIN EN 60076-16:2012-05

Transformers according to this part of IEC 60076 are generator step-up transformers which integrate a wind turbine into the power collection network of a wind farm. The standard applies to dry-type and liquid-immersed transformers with rated power of 100 kVA up to 10 000 kVA for wind turbine applications having a winding with highest voltage for equipment up to and including 36 kV and at least one winding operating at a voltage greater than 1,1 kV. Unless otherwise stated in the standard, the corresponding service conditions and requirements in IEC 60076-11 and IEC 60076-1 apply for the operation of these transformers. The installation of transformers inside an enclosure without active cooling systems increases the transformer temperature. The purchaser shall therefore specify the maximum cooling air temperatures if they are different from those stated in IEC 60076-2. The transformer shall be designed in consultation with the purchaser and according to real ambient temperatures and installation real conditions at enquiry stage. The annex of the standard contains extensive calculation methods and tables as well as considerations for transformers installed in a naturally ventilated area like at the rear of the nacelle or in a separate enclosure installed outside the tower and equipped with air inlet and outlet. In case of transformer installed in the tower or in another location where natural ventilation is not provided, the effects of air inlet and outlet, cooling conditions, efficiency of air cooling and ventilation shall be considered. Information on the air ambient temperature and air flow inside the tower at the enquiry stage is prescribed by the manufacturer. When designing the transformer the manufacturer shall consider the effects of external solar radiation and the losses caused by harmonic currents in order to prevent that excess temperatures of the winding and the liquid exceed acceptable limits. The standard contains all specifications on routine, type and special tests including the environmental test E3. The responsible committee is K 321 "Transformatoren" ("Transformers") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.