Current transformers

  Current transformer is a transformer with primary winding connected to curret source and secondary winding connected to measurement or protective devices with small internal resistance.
  Current measurement transformer is a transformer, designed for conversion of a current to a level suitable for measurement. Primary winding of a current transformer have to be connected in series with the measured alternative current, and the gauges are to be connected to the secondary one. The current flowing through the secondary winding of the current transformer, is proportional to the current flowing through its primary one.
Current transformers are widely used for measurement the electric current and as gauges for relay protection devices of electric power systems, thus high accuracy requirements are superimposed on them.
  Current transformers provide measurements safety by insulating measurement circuits of high-voltage (up to hungreds of kV) primary circuit.
There are high demands of precision for current transformers. As a rule, the current transformers are performed with two and more groups of secondary windings: one of them usually connected to protection devices, and another one - more precise - for connection a counting and measurement means (for example, electric meters).



40,5, 123, 170, 245, 362, 525 kV Oil-immersed current transformers ТФЗМ type

  The oil-immersed current transformers ТФЗМ type are designed for transmission of measurement data signal to measuring, protection, automation, alarm and control instruments in AC 50-60 Hz electric mains.
  They are produced for the rated primary current 15 to 2000 A and the secondary current 1 to 5 A. The transformers external insulation is cylindrical or conical, made from electric porcelain. The main internal isolation of the transformers is polymeric. The windings of the transformer are link chain type. The number of secondary windings from two to five, 1-2 of them are measuring windings and 2 to 4 are protection windings. Accuracy class for measuring windings between 0,1 and 0,5; for protection windings - 10P. The safety ratio of the instruments - 10.
Download the questionnaire TFZM.doc [55 Kb] (downloads: 12)



Current transformers of the TOГ series

Current transformers of the TOM series are manufactured as single-stage for voltage 123, 362, 525 kV, two-stage for voltage of 750 kV.

External insulation of transformers - porcelain cover.

The main internal insulation is oil-paper, capacitor type, located on the ring-shaped secondary winding.

The transformers have five secondary windings.

The design is sealed. The advantages of transformers are: a wide range of products in terms of rated primary current and accuracy class (0.2; 0.5; 0.2S; 0.5S; 5P; 10P);

the ability to manufacture products with any combination of accuracy class and rated secondary load; high reliability and measurement accuracy. Our plant produces the following TOM transformers:

ТОМ 123, ТОМ 362 (ТФРМ 330Б), ТОМ 525 (ТФРМ 500Б), ТОМ 765 (ТФРМ 750А).



Current transformers of the TФУМ series

   Current transformers of the TFUM series are manufactured for a voltage of 330 kV.

External insulation of transformers - porcelain cover. The main internal insulation is oil-paper, capacitor type, located on the U-shaped primary winding. The number of secondary windings is four. The design is sealed.

  The series is characterized by reduced material consumption. The advantages of transformers are: a wide range of products in terms of rated primary current and accuracy class (0.2; 0.5; 0.2S; 0.5S; 5P; 10P); the ability to manufacture products with any combination of accuracy class and rated secondary load; high reliability and measurement accuracy.

  Our factory produces the following transformers: ТФУМ: ТФУМ 362 (ТФУМ 330А).