Three-phase transformers

Three-phase oil regulating transformers with output from 6,3 to 320 MVA and non-regulating up to 410 MVA, nominal voltage up to 420 kV. Transformers by individual customer request with different type of the winding and special dimensions.


Power6,3MVA - 320MVA (non-regulating up to 410MVA)
Voltageup to 420kV

Single-phase power transformers

<!--[if gte mso 9]> <![endif]-->One-phase oil transformers with total output of a three-phase set up to 1200 MVA and voltage up to 420 kV. Regulating and non-regulating 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 350 MVA and voltage 420 kV.

Powerup to 350 MVA
Voltageup to 420 kV

Furnace transformers

We offer special performance regulating and non regulating transformers. Furnace transformers with output up to 80 MVA for power 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.

Starting and special transformers

Specials transformers by customer request. We offer low-noise transformers. We are ready to offer you transformers according to your request. We offer cooperation with technical solution and manufacturing of atypical transformers, for example for rectifiers.


Start-up reactors 6,3 - 22 kV.

Used for series connection for short term limitation at motor starting.

Shunt reactors – for compensation of reactive output     

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.