Manufacturing Process

Transformer Core & Core Assembly
  • The core of the transformers is built from laminated sheets of silicon steel alloy.
  • We use the Cold-rolled grain-oriented electrical steel sheet (CRGO) M5T30 Core or laser treated silicon steel (H0).
  • It is cut on the most modern CNC core cutting machines for step lap construction.
  • The laminations are compacted and clamped together using yoke clamps or tie-bars locking the top and bottom yoke clamps together.
  • The assembled core assembly goes under varnish treatment for hardness of cross section area it protect the rusting from mineral oil at long stage.
  • Each & Every Core assembly passes through pre no load loss test for next stage assembly called core coil assembly.


Winding (Low Voltage & High Voltage)
  • The windings of the transformers are made of high grade electrolytic copper. The High Voltage windings are wound either with round/shaped enamel or paper insulated wire.
  • The Low Voltage windings are wound with shaped, enamel or paper insulated wire or foil.
  • The winding construction is characterized by high dielectric strength with high resistance to atmospheric surges and to the effects of short-circuits.
  • Neutral points of the Low Voltage windings are brought to the tank cover.
  • Low Voltage winding can constructed as layer winding, disc winding, foil winding etc depends on the current and application.
  • High Voltage winding can constructed as layer winding, disc winding, section winding etc depends on the voltage and application.
  • Winding with class-A insulation for oil type transformer
  • Winding with Class- F & Class-H for dry type transformer
  • Winding with oval construction reduced the centre leg hence compact in size.


Core & Coil Assembly and Processing
  • Core assembly to be placed vertically & remove the top yoke.
  • Insulating cylinders are placed around the core to provide the required insulation from the low voltage winding.
  • Complete windings are supported on the bottom yoke with the help of a bed of spacers. Press-ing of the winding is achieved by using vertical tie rods whereas the core bottom and upper yoke is pressed with the help of horizontal tie rods.
  • Upon completion of its assembly with connections the core coil is dried.
  • Oil filling is done under vacuum conditions in order to ensure full and reliable impregnation of the insulation materials free of air voids.
  • Then will guarantee increased high voltage withstand strength. The drying and degassing process of the oil is controlled automatically.


Tank and Painting
  • The transformer tank consists of the bottom plate, frame, and the tank sides.
  • The tank sides are made of corrugated panels in order to increase the total cooling area or sheet with radiators as per customer demands.
  • Corrugated panel & radiators welding is done by welding robot ensuring a consistent and leak proof weld.
  • Tanks are shot blasted and leak tested before final surface treatment and painting.
  • Enclosure for dry type transformer is being made through CNC operated punching & bending machine with powder coating through automatic powder coating plant. All enclosure being made as per customer requirements of IP protection i.e. indoors or outdoors application.
  • Final painting process of Tanks includes shot blasting and thorough cleaning before applying the liquid/flood painting with shade Color RAL 7032/7035 or as per the customer requirements.


ENERGY EFFICIENCY (Star Rating Transformer)
Energy Efficient transformers are designed with lower than normal conductor and total losses. Temperature rise is therefore lower resulting in greatly improved life expectancies and sub-spatial increases in overload capabilities; overload, without high magnetic permeability provides reduced core induction levels, preventing saturation as a result of the higher frequency harmonics and resultant peak voltages. In a core approaching saturation, the current in the coil will increase as voltage drops because the core cannot absorb the additional magnetic flux. This core also provides reduced eddy currents or induced currents in the steel caused by the high ratios of peak-to-RMS currents and voltages found in harmonic loads.

Neutral Bus - The neutral bus is sized and configured to accommodate at least 200% of the rated current. This compensates for the increased neutral currents found in non-linear loads thus reducing heat.

Insulation - Class-A, F & H insulation systems are fully vacuum impregnated and protected

 

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