Oil-immersed power transformers are electrical appliances that use insulating oil as the insulating, medium and are composed of cores, coils, voltage regulator switches, oil tanks,etc. to change voltage and transmit AC power. it has the characteristics of small size andstrong weather resistance. Applicable to power systems, industrial and mining enterprises.transportation, post & telecommunications and scientific research bureaus, etc. it isdivided into flat stacked core series, three-dimensional roll-core series, amorphous alloyseries and other products below 35kV. The structure is flexible and diverse, the appearanceis good-looking, and it can meet the needs of different users.

PRODUCT SERIES

10kV PRODUCTS

S11(S13,S20、$22) series three-phase oil-immersed self-cooling double winding non-excitationvoltage regulating distribution transformer

S13(S200S22)-M.RLseries three-phase oil-immersed three-dimensional roll-core self-cooling@double winding non-excitation voltage regulating distribution transformer

SH15(SH211SH25) series three-phase oil-immersed self-cooling amorphous alloy core doublewinding non-excitation voltage regulating distribution transformer

20kV PRODUCTS

S11 series 20kV three-phase oil-immersed self-cooling double winding non-excitation voltage[regulating distribution transformer

S13 series 20kV three-phase oil-immersed self-cooling double winding non-excitation voltageregulating distribution transformer

35kV PRODUCTS

S11 series 35kV three-phase oil-immersed self-cooling double winding non-excitation voltageregulating distribution transformer

Note: lf you need other types of single-phase and three-phase oilimmersed distribution transformers of 10-35ky, please contactour transformer team for specific technical parameters and requirements.

NORMAL USE

CONDITIONS OFTHEPRODUCT

Ambient air temperature:+40°C--45°C;

Monthly average hot temperature:+30°C;

Annual average hot temperature:+20°C;

Altitude:≤1000m;

Pollution level: class lll ;

Power supply voltage waveform: approximately sine wave ;

Note: lf the use condition is more special than the above-mentioned conditions, please contact our transformer team forspecific technical parameters and requirements.

PRODUCT PERFORMANCE ADVANTAGES (PLANAR LAMINATED CORE)

There are no oil protection devices such as oilconservator and moisture absorber to ensurethat the transformer oil does not come intocontact with the air and ensure that thetransformer oil can be used continuously for20 years without any treatment.

Equipped with signal thermometer andpressure release valve,which enhances thereliability of operation.

The seals are made of rubber with excellentperformance,which can effectively preventphotoaging,electrical aging and thermalaging.

Using the vacuum oil injection process,external moisture and oxygen cannot enterthe oil tank, thereby slowing down the agingrate of the insulating material and increasingthe service life of the transformer.

Changes in the volume of the transformer arecompensatedbytheexpansion andcontraction elasticity of the corrugated tankwall.

It is wound with high-strength enameled wire(or paper-covered wire), has a cylindrical(orcake-type)structure,evenly distributedampere-turns，reasonable insulationstructure,and has high short-circuitresistance

No hanging core inspection is required beforethe product is put into operation, andmaintenance and upkeep are not requiredafter it is put into operation, which greatlyimproves the reliability of the operation.

The fasteners used in the fuel tank all useloose-proof nuts,which will not loosen evenafter long-distance transportation.

PRODUCT PERFORMANCE ADVANTAGES (THREE- DIMENSIONAL ROLL-CORE)

Magnetic circuit optimization

There are no seams between the layers of the three-dimensional winding core, the magnetic circuit is evenlydistributed throughout, there is no obvious high-resistance area, and there is no distortion of the magnetic flux density at the seams. 

The direction of the magnetic flux is completely consistent with the orientation ofthe silicon steel sheet. 

The three-phase magnetic circuit lengths are equal, and the sum of the three-phase magnetic circuit lengths isthe shortest.

The three-phase magnetic circuit is symmetrical, and the three-phase no-load current is balanced.

Low loss and significant power saving effect

The magnetization direction of the three-dimensional roll-core is completely consistent with the rolling directionof the silicon steel sheet, and there are no overlaps between the core layers, The magnetic flux is evenly distributedthroughout the magnetic circuit, with no obvious high-resistance areas and no magnetic flux density distortion onthe joints, On the premise of the same material, compared with the laminated core, the iron loss process coefficientof the core is dropped from 1.3-1.5 to 1.05, this alone can reduce core loss by 10-20%.

Due to the special three-dimensional structure, the amount of material used in the yoke part of the core isreduced by 2596 compared with the traditional laminated core, and the reduced angular weight accounts forapproximately 6% of the total weight of the core

The shearing treatment of the silicon steel sheet will deteriorate its magnetic permeability, and the three-dimensional roll-core will undergo high temperature (800"C) vacuum nitrogen-filled annealing treatment not onlyeliminates the mechanical stress of the core, but also refines the magnetic domain of the silicon steel sheet,improves the secondary recrystalization ability of the silicon steel sheet, and makes the performance of the siliconsteel sheet much better than its original performance.

low noise

The root causes ofnoise caused by the vibration ofthe transformer body are:

1) The magnetostriction of the silicon steel sheet causes the iron core to vibrate and generate noise;

2) There is electromagnetic attraction caused by magnetic flux leakage between the joints of the silicon steel sheets andthe laminations,causing the core to vibrate and generate noise;

3) The operating magnetic density of the transformer is too high, approaching or reaching the saturation point, and themaaneticleakageis too large,generate noise.

Since the three-dimensional roll-core is made by rolling silicon steel sheet strips continuously and tightly on adedicated core winding machine, there are no seams and no noise caused by discontinuous magnetic circuits like thelaminated core. At the same time, the three-phase magnetic circuit and magnetic flux are completely symmetrical,and the operating, magnetic density is reasonably designed, so the product noise is greatly reduced.

STRUCTURAL FEATURES

Core

The core is made of high magnetic permeability and low losssilicon steel sheets or amorphous alloy materials, and has aladder-shaped multi-level joint structure, which is beneficial toreducing no-load loss and no-load current.

Winding

Class A or above insulating materials are used. The high-voltagecoil adopts multi-layer cylindrical type, which has highproduction efficiency and good resistance to impulse woltage.The low-voltage coil mostly adopts foil type; the space utilizationrate is good and the inter-layer capacitance is evenly distributed.

Clamp

1-shaped channel steel is used to tighten the core and stabilizethe body to clamp and prevent loosening, The core is alsogrounded at a single point through the clamp.

Tank

The transformer oil tank body and insulating oil to isolate air andmoisture.Corrugated sheet rectangular oil tanks are often usedThe elasticity of the corrugated sheet can compensate forchanges in the volume of the transformer oil caused bytemperature rise and fall.