Three-phase transformers

Three-phase oil transformers with output from 6,3 to 450 MVA, nominal voltage up to 420 kV. Transformers by individual customer request with different type of the winding and special dimensions.


Power6,3MVA - 450 MVA
Voltageup to 420kV

Single-phase power transformers

One-phase oil transformers with total output of a three-phase set up to 1200 MVA and voltage up to 420 kV. Transformers according to individual customer request with different type of winding, cooling and specific dimensions.

Powerup to 1200 MVA
Voltageup to 420kV


Autotransformers are specific by having two coils, while one has dual use. Autotransformers are smaller, lighter and having lower losses. ETD offers autotransformers with output up to 450 MVA and voltage 420 kV.

Powerup to 450 MVA
Voltageup to 420 kV

Furnace transformers

Transformers with output up to 80 MVA for powering of electric furnaces.

Traction transformers and chokes

Transformers and chokes for railway vehicles. ETD is manufacturing components for the Czech railway company České dráhy a.s. but sells these products to other companies abroad as well.

Special transformers

We are ready to manufacture transformers according to your request. Our solutions adapt to parameters such as:

  • low-noise
  • impedance voltage
  • outlet configurations
  • cooling
  • special monitoring devices
  • adaptation to dimensional restrictions of the installation site


Start-up reactors (6,3 - 22 kV) - short term limitation at motor starting

Shunt reactors – for compensation of reactive power

Saturation reactors - with fluent power regulation

Repairs and maintenance


  • Oil transformers with output from 1 to 400 MVA
  • Furnace  transformers
  • Autotransformers

Technical Support:

  • Transformer testing prior to commissioning
  • Transformer Diagnostics
  • Transformers Technical checkup

All activities are performed on transformers produced by ourselves as well as by other manufacturers.

Spare parts

ETD offers the spare parts for transformers produced by ourselves as well as by other manufacturers