How do transformers work?

How do transformers work? – know more about 4 different types of transformers

Transformers transfer power from one circuit to another without changing the frequency, thus protecting the secondary circuits and people from electric shocks with the change of voltage and current. Transformer based technology greater than 100 kVA (one power unit – one kilovolt ampere equals 1000 volts ampere) is suitable for industrial applications.

How Transformer Works –

The transformer consists of an input connection, an output connection, a core and windings or coils. When the input voltage is applied to the primary winding, the AC flows in the direction of the primary winding and sets the changing magnetic field in the core.

When this magnetic field crosses the secondary winding, an alternating voltage is generated on the secondary winding. Voltage The ratio between output voltage and input voltage is equal to the ratio of the number of turns between the two windings. The ratio voltage between the actual turns of the wire in each coil determines the output voltage and hence the type of transformer.

The two types of transformers available in the industry are listed below:

    a. Step-up transformer: The output voltage of this transformer is higher than the input voltage and if the secondary winding changes the wire more than the primary winding, the output voltage will increase.

    b. Step-by-step transformer: Here the secondary winding has less turns than the primary winding and the output voltage is lower.

Adherence to the latest technology and quality control measures ensures that it works smoothly. Some of the key features of a good transformer are:

    i) Air flows between the coils and from layer to layer between the coils and the core, so that heat escapes faster and the temperature decreases.

    ii) Compact and lightweight

    iii) Moisture-proof & powder-proof

    iv) Insulation Class H or F.

    v) Low noise

1. Power Transformer:

A power transformer is a type of transformer used to transfer power to any part of the electrical or electronic circuit between the generator and the supply primary circuits. These transformers are used to increase and decrease voltages in distribution systems.

The normal life force of these transformers is 30 years if the transformer is immersed in fluid composed by Control Transformer manufacturers. Power transformers can be divided into three types based on ranges: small, medium and large.

Power Transformer Applications:

a. Applications of the power transformer include power transmission and distribution.

These transformers are widely used in power plants, industrial plants and traditional electric utility companies.

b. Power transformers can switch from one voltage to another at high power levels.

These transformers are used in a wide variety of electronic circuits and are available in a wide variety of applications.

c. Compared to supply transformers, these transformers are larger in size and are used in the construction of station and transmission substations.

d. Power transformers are used in high voltage transmission networks. These transformers are commonly used for load loading.

e. Power transformers are primarily designed to maximize the core component and operate near the knee of the B-H curve. This drastically reduces the mass of the core. Naturally, power transformers have copper loss and iron loss at high loads.


2. Distribution Transformer:

The main function of this transformer is to convert high voltage to normal voltage such as 240/120 V for use in power supply.

Types of distribution transformer –

Single phase–

These transformers are used exclusively for networks that do not require a three-phase supply.

Typically, these are used to repair overhead distribution loads in residential areas.

Three phase–

This type of transformer is used to store power from the main supply circuit to the short supply circuit assembled by Three Phase Transformer manufacturers.

This type of transformer transfers current to the secondary supply circuit and reduces the voltage of the primary supply circuit.


This transformer is used with electrical power distribution lines in the overhead electrical line to reduce the primary voltage to be supplied to the consumers. The power rating of this transformer ranges from 75 kV to 5000 kV and includes fixed switches and fuses.

Pole-mounted –

These transformers are mounted on the electrical service pole at the height of the overhead cables.

These are used to convert high supply voltage to 120/240 volt power. Such transformers are used in wide rural areas from 16 kVA to 100kVA.


   a. This transformer converts high voltage power used in homes and businesses into low voltage power.

    b. Its main function is to reduce the voltage to provide isolation between two windings, such as primary and secondary.

c. This transformer supplies electricity to remote areas generated by power plants.


3. Core-type & Shell-type transformer (types by design):

In a core-type transformer, the windings supply a significant portion of the core. The coils used for this transformer are of foam-wound and cylinder type. This type of transformer applies to both small and large size transformers forged by Rectifier Transformers manufacturers. The coils used are small in size; the core is rectangular and cylindrical.  A wound on circular or cylindrical coils can be seen to fit into a cruciform core section. In the case of circular cylindrical coils, they have a good advantage of good mechanical strength. The cylindrical coils consist of different layers, each layer insulated from each other with the help of materials such as cloth, paper and micarta board.

In shell-type transformers, the core revolves around a significant portion of the winding. The coils are foam-wound, but the multi-layer disc type is usually rolled in the form of pancakes.

Paper is used to insulate different layers of multi-layer discs. The entire winding consists of discs stacked with insulation gaps between the coils. These insulation gaps provide horizontal cooling and insulating ducts.


4. Oil filled self-cooled type and water-cooled type transformer (types based on cooling method):

In small and medium supply transformers oil-filled self-cooling type are used. The composite windings of such transformers are placed in sealed oil-tight steel tanks supplied with a core steel cover.

Once the core is in place, the tank is filled with refined and high quality insulating oil. The oil helps to transfer heat from the core and windings to the surrounding area.

Oil filled water-cooled type transformer is used for more economical construction of large transformers because the self-cooling method mentioned above is very expensive.

The same method is used here- the windings and the core are immersed in oil. The only difference is that the cooling coil is placed near the oil surface, through which cold water continues to circulate. This water contains heat from the device. This design is typically implemented in transformers used in high voltage transmission lines generally crafted by Oil-Cooled Transformers manufacturers. The biggest advantage of such a design is that such transformers do not require extra housing other than their own. This reduces the cost by a large amount.


Author BioGraphy

Mr. Neeraj is a renowned creative head at Muskaan Power Infrastructure ltd. With years and years of experience writing IT Services and content marketing, she has an exceptional writing style that shines through in her guest posts. Mr. Neeraj has a successful career in creative writing before fulfilling her dream of becoming a creative head of the company. 

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