Varelen Electric Co., Ltd

Liquid Immersed Transformer

  • •oil immersed transformer use ester oil is that it is not flammable, superior fire safety
  • •Strong resistance to short circuits
  • •COMPACT design
  • •largely reduce non-load losses by adopting amorphous or high quality silicon steel core,
  • •High temperature resistance insulation  system
  • •Efficient transformer with reduced losses
  • •The Tank withstanding pressure up to 115kPA  comply with FM3990 requirements
  • • the transformer tank must stay securely sealed, enduring mechanical strain and remaining unaffected by wind or weather conditions
  • •hot-dip galvanization can be request
Liquid Immersed Transformer
oil immersed transformer
Liquid immersed transformers
Oil type transformer
hermetically sealed  transformer

Related product parameters

Main Specification
Transformer Type Oil immersed
Rated capacity up to 40MVA
Rated voltage up to 132kV
Frequency 50 or 60Hz
Phase single phase  or three phase
Winding material Copper or Aluminum
Tap changer Off-load or on-load
Insulation class A, E, B
Marine Coating C4,                                                                           C5 ((very highly corrosive, marine environments )
Vector group

Dyn11, YNd1d1, Yyn0, YNd11 etc.

Cooling

ONAN , ONAF, KNAN, KNAF etc.

Bushing  ceramic insulators or  epoxy resin bushings
Insulation level 

11KV       BIL   95KV

22KV       BIL   150KV

33KV       BIL   200KV

Ambient temperature

-45°C  + 60°C

Altitude

5000M( on request)
Dielectric fluids Mineral oil,  Silicone,  Vegetable Oil
Standard 

IEC, AS, EN, IEEE/ANSI, GOST

Accessories

Bushing

Oil level gauge

Transformer tank

pressure relief valve

Tap changer

Oil Thermometer

Buchholz-Relay

Why choose Varelen oil immersed transformer? Safe and environmental friendly transformers

1. Magnetic Core

The three-limb iron core is made of oblique cut Grain-oriented, seven-step silicon steel lamination insulated on both sides, guaranteeing low losses and low noise.  It is protected on the surface with a flash-proof varnish in order to prevent the sheet from corrosion and to reduce the noise.

 

2. Transformer winding

The winding as the centerpiece of the transformer must be especially protected  both against high electrical stress due to external over voltages and against mechanical overloads by short circuits. Huarui transformers are systematically designed to meet these requirements. The windings are made of copper or aluminum. Low-voltage windings are made of strip or flat wire, and the high voltage windings are manufactured from round or profile wire. (diamond-dotted paper) bonds the winding into a compact block while drying and increases the short-circuit capacity additionally.

 

3. Paiting

oil Immersed Transformers colour is  RAL 7033. Transformer tanks are painted by the method of dipping or spraying.  and offer anti-corrosion paint C5, also can supply (zinc coating) according to the customer requirements.

 

Areas of applications

Oil immersed Distribution transformers by Varelen  used for a wide range of applications.

  • wind                       • solar                   
  • power plants          • utilities               • metal and mining  
  • pulp and paper      • oil and gas          • industry        
  • infrastructure         • Residential & Commercial Buildings

7300kVA oil immersed transformer

customized oil immersed power transformer

 

oil immersed transformer drawing

 

 

FACTORY TEST

For each transformer are prepared and issued a test report, in accordance with IEC 60076. except for routine tests, we also offer type tests and specialized tests to meet all customer requirements. We make what matters work for our customers in a safe and reliable way.

distribution transformer testing

Routine test

  •  Measurement of winding resistance
  •  Measurement of voltage ratio and check of phase displacement
  •  Measurement of short-circuit impedance and loss
  •  Measurement of no-load loss and current
  •  Dielectric routine tests
  •  Tests on on-load tap-changers, where appropriate
  •  Leak testing with pressure for liquid-immersed transformers(tightness test)
  •  Tightness tests and pressure tests for tanks for gas-filled transformers
  •  Check of the ratio and polarity of built-in current transformers
  •  Check of core and frame insulation for liquid immersed transformers with core or frame insulation

 Type test

  •  Temperature-rise type test
  •  Dielectric type tests
  •  Determination of sound level for each method of cooling for which a guaranteed sound level is specified
  •  Measurement of the power taken by the fan and liquid pump motors
  •  Measurement of no-load loss and current at 90% and 110% of rated voltage

 Special Test

  •  Dielectric special tests
  •  Winding hot-spot temperature-rise measurement
  •  Determination of capacitances windings-to-earth, and between windings
  •  Measurement of dissipation factor(tanδ) of the insulation system capacitances
  •  Determination of transient voltage transfer characteristics
  •  Measurement of zero-sequence impedance(s) on three-phase transformers
  •  Short-circuit withstand test
  •  Measurement of d.c. insulation resistance each winding to earth and between windings
  •  Vacuum deflection test on liquid immersed transformers
  •  Pressure deflection test on liquid immersed transformers
  •  Vacuum tightness test on site on liquid immersed transformers

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