Power Transformers

Scheme and connection group of windings is optional: Dyn0,Dyn5,Dyn11,YY0 etc. according to customer demand it is possible to make transformers with different connection of the Voltage s and other construction solution.

Service environment:

a) Air temperature: Maximum temperature: +40℃; Minimum temperature: -25℃.

b) Humidity: Monthly average humidity 95%; Daily average humidity 90%.

c) Altitude above sea level: Maximum installation altitude: 2500m.

d) Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.

e) No frequent violent shake.


1. Energy saved :

Compared with old type S7, no-load loss decreases 10.25% averagely and on-load current decreases 37.9%, which means 18.39% operation cost is reduced.

2. Long-term reliable service life: 

Fully enclosed transformer tank and rim shall be bolted together or welded firmly. Isolation between oil and air keeps insulation away from moisture, which lowers insulation aging and improves service life.

3. Free from untanking:

Free from untanking before operation, so its cost is saved.

4. Free from maintenance

5. Low noise:

Impacted structure in design, new material and new technology adopted and low noise.

6. Small size and artistic appearance:

Owing to the corrugated plate used for radiation, oil volume is changed by adjustment and compensation through expansion and shrinkage of corrugated plate when the temperature of oil is changed. Corrugated tank is small size in good looking.

1. Energy conserving

Compared with the original S9 type, no-load loss of S11 decreases by 10.25% averagely, no-load current decreases by 37.9%, and the running expense decreases by 18.9% averagely.

2. High reliability

Structurally improve the effective supporting of both HV and LV coil end faces, adopt the new body location structure. Expand the application scope of the cylindrical coil, and adopt a series of new material, new subassembly, new fastening pieces and new process to make both the performance of the product and structure reach up to higher level, improve the running reliability of the product.

3. The service life is prolonged

Compact structure, small volume, low noise, high efficiency and steady performance of S11 series of transformers prolong the service life of transformers.

S11 series of oil-immersed transformers produced by our company are low loss series of products that have international advanced level. The energy conserving effect is significant. They can be widely used in urban and countryside industrial and agricultural power grid. The iron core adopts the new process of the stepping lamination, resulting in improvement in no-load performance and reduction in noise.

Transformers are equipment which convert the voltage transmitted by the grid to lower voltage as required by the system or load. Amorphous alloy transformers are widely used in the distribution systems of urban and rural areas. The main feature of the product is that it can significantly reduce no-load loss of transformers, and is especially suitable for areas which lack power, have a fluctuating load, low load rate, or hard to perform daily maintenance. Because the insulating medium cannot easily be polluted by air due to the full seal structure, the transformer can be operated in humid environments, which is ideal distribution equipment for urban and rural grids. The products will save energy and decrease pollution to the atmosphere effectively if they are widely installed and operated properly.

Working conditions:

  1. Altitude: ≤2000m
  2. Maximum environmental temperature:
  3. Maximum annual average temperature
  4. Customized products are available.

Transformer cores are made of amorphous alloy strips, with no-load loss 70% lower than the current S11 types. Its performance parameters comply with the requirements of GB/T25446-2010 standards.

The LV winding of the transformer is foil wound, which increases the mechanicalintensity of windings and improves the ability of transformers to endure short circuits.

The connection symbol of the transformer is Dyn11, decreasing the impact of harmonic wave on the grid and improving the quality of power supply.

We adopt a full seal structure in oil tanks of transformers, preventing the insulating medium from coming into contact with the air, prolonging the use life of products and increasing the operational reliability of transformers.  

The transformer uses vacuum oiling, which can eliminate the bubble in windings completely, and ensure stable and reliable insulation performance.

To ensure transformers can be operated safely and reliably, we will carry out a full wave thunderbolt surging test on each transformer at a peak value voltage which is 25% higher than that of the national standards. (We don’t have the ability to do a surging test currently.)

Because the acceptability of amorphous alloy cores to mechanical intensity and the mechanical strength of rectangle wirings are weak, it is difficult to pass the test for short circuit of amorphous alloy transformers successfully in the transformer field. Our company overcame the difficulty with our mature technical expertise and experiences, which indicates the transformer design and manufacture technology of our company is among the best in the domestic transformer industry.

Insulation Level of the Product


Max RMS voltage of transformer


Rated short-time power frequency RMS withstand voltage


Rated lightning impulse withstand voltage full-wave (peak)



















Product Standards

GB1094.1-1996 Power Transformer   Part I     General Rules

GB1094.2-1996    Power Transformer   Part II    Temperature Rise

GB1094.3-2003    Power Transformer   Part III    Insulation level, insulation test andexternal insulation air gap

GB1094.5-2003    Power Transformer   Part V    Ability to withstand short-circuit

GB/T25446-2010   Technology parameters and requirements for oil-immersed amorphous alloy distribution transformer

GB/T22072-2008   Technology parameters and requirements for dry-type amorphous alloy core distribution transformer

GB1094.11-2007    Dry-type power transformer

IEC 60076              Power transformer 

D11-М transformer adopts laminated core and is characterized by low loss, low noise level and others: DH15-M transformer adopts amorphous alloy core which further reduces the no-load losses of the transformer. Table below specifies technical parameters and dimensions of the two series of transformers.

We developed SC9,SCB9 series and SC10,SCB10 series padding thin-insulation dry-type distributing transformer whose winding is sealed up with epoxy, therefore the resin insulating dry-type transformer is flame-retardant, explosion-proof, free from maintenance and pollution, and it is compacted and can go deep into load center.

Besides, with scientific and reasonable design and coating craft work, it has advantages of low partial discharge capacity, low noise, good heat dispersion and it can run over a long time with 125% rated load in the circumstance of cold wind. It applies intelligent thermal controller and has the functions that it will alarm when there is fault or the temperature is exceeded and switch off as well as the function of ”black box”. It can be monitored and controlled by connecting it to the computer through its RS485 serial interface.

 Model Description:


 C---------------------------------solidification forming (epoxy resin cast)

 B---------------------------------LV foil coil

 9---------------------------------performance code

 □--------------------------------rated capacity (KVA)

 □--------------------------------rated voltage (HV KV)

Working conditions:

1. Altitude: ≤2000m in indoor or outdoor use

2. Maximum environmental temperature: +40℃, maximum daily average temperature: +30℃

3. Maximum annual average temperature: +20℃, minimum temperature: -25℃

4. Customized products are available.

Performance characteristics:

1. The iron core is produced with high quality grain orientated cold rolled silicon steel sheet, thickness: ≤ 0.3 mm, 45°full oblique ladder type lap. Core surface is packed with protective resin to be well protected against moisture and rust

2. Low voltage winding usually adopts copper foil winded cylindrical structure except of using copper conductor for small capacity ones;High voltage winding uses multi-layer cylindrical structure, which makes a balance ampere-turns distribution, small magnetic-leakage loss, strong mechanical strength and good anti-short circuit ability.

3. The transformer can be configured with bass air cooling device, realizing automatic fan on and off through temperature controller operation.

4. We can start and close fan or give warnings and breaking circuit via temperature sensing element and sensor system buried in low voltage winding, to protect the transformer.

5. IP20: Avoid things with diameter > 12 mm into the shell. IP23: Avoid water with ≤60°vertica angle into the shell. The protection case can plays a role of preventing small animals into then causing short-circuit faults, as well as protecting human safety.

  • The no-load loss of SC(B)9 is the same as that of GB/T10228-2008.
  • The load loss of SC(B)9 is the same as that of GB/T10228-2008.
  • The no-load loss of SC(B)10 is 10% less than that of GB/T10228-2008.
  • The load loss of SC(B)10 is 5% less than that of GB/T10228-2008.

Model Description

S------------------------------three phase

G -----------------------------non-encapsulation dry type

B----------------------------- LV foil coil

10 ----------------------------performance code

□------------------------------rated capacity (KVA)

□------------------------------rated voltage(HVKV)

Working conditions:

1. Altitude: ≤2000m in indoor or outdoor use

2. Maximum environmental temperature: +40℃, maximum daily average temperature: +30℃

3. Maximum annual average temperature: +20℃, minimum temperature: -25℃

4. Customized products are available.

Working conditions:

1. Altitude: ≤2000m in indoor or outdoor use

2. Maximum environmental temperature: +40℃, maximum daily average temperature: +30℃

3. Maximum annual average temperature: +20℃, minimum temperature: -25℃

4. Customized products are available.