Transformers

MV/LV Dry Type Transformers

A distinctive element of the dry transformer is the fact that   the magnetic circuit and the windings are not immersed in an insulating liquid. It could be   MV/LV, MV/MV, or LV/LV   with cast coils or resin impregnated coils.

Cast Resin Transformer:

  • The MV coil – cast in resin
  • The LV coil- cast or impregnated in resin.

Definition impregnated in resin (in-air transformer)

  • The MV coil – impregnated in resin
  • The LV coil – impregnated in resin

The core is made of high magnetic permeability grain-oriented electrical sheet, with with a 45 degree cut and intercalated step lap joints method.   Alternatively, it could be of amorphous type, and which is a crystalline structure that guarantees  extremely low losses, up to 4 times lower compared to the standard grain oriented solution.

The MV windings are made with fully automatic machines which insulate the wire or strip, either aluminium or copper, with class F or H insulation materials. The MV windings can be impregnated in polyester resin or cast in epoxy resin. The epoxy resin is loaded with aluminium, silicone and other additives that modify the mechanical characteristics and the TG (transition temperature). This guarantees to meet  the most severe climate and environmental classes such as: low temperatures down to -60°C or high temperatures up to +60°C, and any other saline high condensation environment or environment with high pollution as required by the regulations in force for some types of application.

The LV windings are made of aluminium or copper foil or strip,   insulated with class F or H materials and vacuum pressure impregnated with class H high cementing polyester resin that gives the coil excellent insulation and mechanical sealing. For special applications   the insulation used is the pre-impregnated type and on request can be cast on an epoxy resin mould. The terminals are automatically welded for the whole length of the winding, to provide easy accessibility and high mechanical resistance to electrodynamic stresses.

All steelwork is of GBE production and is galvanised to allow installation in even the most aggressive environments. For some installations, the transformer can be equipped with IP protective box   required for indoors or outdoors.

Therefore, GBE production are suitable for   installations in hospitals,   banks,   public   and   residential buildings, and also on ships,   galleries,   subways   and   offshore platforms.

Specification

  • Standardowe wykonanie w klasach E2, C2, F1
  • Specjalne zastosowania w temperaturach - 60°C, gwarantowana klasą C4 ( zgodną z GOST-R54827-2011)
  • Uzwojenia zalewane próżniowo żywicą epoksydową lub impregnowane żywicami poliestrowymi w klasie H

MV/LV Oil transformers

In this type of transformer, the magnetic circuit and the windings are immersed in   an insulating liquid such as mineral, silicone, ester or vegetable oil. The choice of oil is linked to the type of installation and the specific requirement of the Customer and where it is necessary to ensure special guarantees in terms of environmental impact and safety in the event of a fire.

GBE SpA manufactures  oil transformers for all applications, in particular transformers for   distribution   and special   MV/LV, MV/MV, LV/LV, HV/MV, HV/LV and HV/HV transformers with power from 50kVA up to 50 MVA, up to voltages of 145 kV (BIL 650 kV), with vacuum or load tap changer.

The primary and secondary windings of the oil transformers are built of aluminium and/or copper with conductor insulation made of   pure cellulose paper   or, for small diameter wires, of   double enamel.

These windings have an oval or circular section and concentric type, coaxial to the columns of the core.

The transformers can be hermetically sealed, with an air/nitrogen cushion or with conservator.

Transformers up to 6,300 kVA can be with finned tanks, but it is recommended for power above 3,150 to provide the conservator. For bigger powers, cold rolled stamped steel, galvanized radiators are provided on request.

GBE steelworks can create not only the profiles and bases used in transformers, but also standard finned  tanks, standard radiators and special tanks for special requirements on the positioning of the terminal or for specific dimensions. The transformer may be provided with a protective box on the LV side and/or on the MV side  or on both sides. Special cable box can also be provided with above or below cable entry, complete with connection bars, if necessary. Upon request, transformer can be supplied complete with a circuit breaker/switch on either the MV side or the LV side.

The surfaces of the domestic manufactured tank are treated with suitable preparation processes, phosphating, washing and coated with water-based coatings using the  flow coating RAL 7031 method (approved by ENEL)   or RAL 7033 which ensures excellent resistance of the coating in all environments. The guaranteed minimum thickness depends on the coating cycle requested, which can provide multiple layers with different coatings . The standard coating cycle is the C3, but for industrial or coastal areas with high humidity and corrosive atmosphere, GBE guarantees C4, C5i and C5M cycles.

 

Specification

  • Rdzeń magnetyczny
  • Uzwojenia średniego i niskiego napięcia
  • Przełączników zaczepów do regulacji przekładni
  • Izolatory

Power Transformers

GBE S.p.A. produces Resin and Oil Power Transformers covering a vast variety of application fields. Transformers are sperciafically designed and manufactured with GBE state of art construction technology to guarantee perfect performance also in case of loads with high harmonic content.

GBE Power Transformers are certified by internationally recognised certification bodies. Furthermore, standard and special tests are also conducted, according to the customer specifications.

 

Specification

  • Uzwojenia pierwotne i wtórne transformatorów olejowych wykonywane z miedzi elektrolitycznej
  • Przełączniki zaczepów do regulacji napięcia
  • Kadź z radiatorami chłodzącymi