Power Transformers

ELTAŞ A.Ş. can produce High Voltage Oil Immersed Power Transformers up to 250 MVA 420 kV in Aliağa Production Facilities.

ELTAŞ A.Ş. is fully equip with expert engineers, equipments and tools to answer all kinds of customer’ requests in design, production, tests, site assembly and maintatance related matters.

Each transformer is designed with a tailor-made approach, taking into account its specs and environmental working conditions. The element affecting the efficiency and performance of the transformer are handled with care during the design stage.

The following activities are used to ensure reliability of product:

  • Design optimization, considering of design relation to labor and material costs
  • Loss evaluation
  • Low noise level
  • Distribution of voltage stresses under impulse lightning
  • Behavior during short circuit conditions
  • Both transient electrodynamics and continuous thermal withstand analysis of those areas where high electrical stresses can occur
  • Optimization of the insulation structure design
  • Calculation of stray losses
  • Thermal effects

Our purpose is to fulfil our customer demands with the highest quality

We produce power transformers according to customer demands, contract conditions and technical standards (TS 267 EN 60076-1 IEC 60076-1, BS 171, DIN, ANSI, ENEL, ENDOSA, CSA etc.).

  • Generator Step Up Transformers
  • Auto Transformers
  • Multi Winding Auto and Separate Winding Transformer
  • Special Transformers
  • Furnace Transformers
  • Earthing and Auxiliary Transformers
  • Package and Mobile Substation
  • Single Phase Rail System Transformers
  • Convertor Transformers
  • Recators (up to 50 MVAr)

1 - Coil Winding

2 - Core Production

3 - Solvent Base Drying Chamber

4 - Assembly Hall

5 - Quality Control & Testing


Our transformer are designed according to “ core type” design. Slitting and cutting of core is done “ in house”. Core are manufactured from high quality standards also high quality cold – rolled grain oriented silicon steel laminations, which are coated with carlite.


All winding are of the circular type, since this type has the highest resistance against short circuits. Depending on the specific design criteria, layer, helical, disc, partly interleaved or fully interleaved winding are also used.


Tank design is competely done by 3-D CAD on computer, which determines the optimum size and the number and location of needed supports, which makes handling, assembely and instalation easier for customer.

  • All welds are tested, ensuring 100% leak proof seams and maximum mechanical strength.

Cooling system

  • All transformer are equiped with detachable panel radiators, which are connected to top and bottom headers.
  • Most commonly natural air/ forced air cooling is used to accelerate the cooling process (NAN/NAF).
  • Other cooling methods such as forced oil/ forced air (OFAF), Directed oil / forced air (ODAF), forced oil / forced water (OFWF), directed oil / forced water (ODWF) are also available if required.

Engineering Tools


System used for design and drawing of transformer tank, coolers and active part. Reduced lead time and increased accuracy.


May also be used for mechanical analysis. Here, the vibration levels on the end panel of a transformer tank were calculated and compared with the measured values.


  • Calculation of two-dimensional plane or axissymmetric electrostatic field.
  • Calculation of impulse stresses on main and longitudinal insulations of Transformers.
  • Definition of impulse voltages between any points of windings.
  • Calculation of transformer tanks, yoke beams and pressing rings for mechanical strength at Short circuit, Pressing, Lifting, Vacuuming and Transportation modes.
  • Calculation of electrodynamic stability of transformer windings at short circuit.

Benefits of engineering tools :

  • Reliable design
  • Electrical stresses within safe limits
  • Optimized insulation structure
  • Low risk of failure
  • Long lifetime
  • Optimized tank design
  • Lower tank weight
  • Lower noise
  • Increased reliability