Power transformers: Definition, Types, and uses


A static or power transformers is a device that transfers electrical energy from one circuit to another by electromagnetic induction (also called transformer action). It widely uses stepping up or step-down AC voltage.

The transformer has no moving parts, there is no rotating magnetic field in a transformer like the induction motor, and hence no torque is generated to keep one of the windings in motion. So, it is known as a static device.

History of power transformer

If you like to know about power transformers, let us time travel to ancient days. As Power Transformers Manufacturers India discovered induction during the early 1830s, this power transformer uses this property as a working principle.

The evolution resulted in a smaller size of the transformer and improved its efficiency. Slowly, various ranges such as MVA, KVA of large transformers came into existence.

In the electric voltage supply power plant, manufacturers introduced electrical power transformers of 400 kV in the early 1950s. Later, the range increased to 1100 MVA, which produced a more extensive power system. Various Power Transformer manufacturers India manufactured several higher rate transformers as years passed.

Types of Transformers

Power transformer manufacturers India produces transformers based on use, purpose, principle, built system, etc. Sometimes, the classifications overlap; for example, a transformer can simultaneously act as a step-up transformer and a 3-phase transformer.

Core type transformer

This transformer is classified based on the windings of the transformers,

which are core type and shell type.

It has two vertical limbs or legs, and two horizontal parts called a yoke. Core type transformer’s coil is rectangular that includes a standard magnetic circuit. There is a cylindrical coil placed on the limbs of the transformer.

Shell type transformer

It generally has two outer limbs and one central limb. The coils are placed on the central limb. The core has a double magnetic circuit.

Berry type transformers

The core in a berry type looks similar to the spokes of a wheel. The housing is done with the help of tightly fitted metal sheet tanks. This transformer is also filled with transformer oil.

Step-up transformer

Converting high current value and the low voltage from the primary side of the step-up transformer to low current value and the high voltage from the secondary side of the step-up transformer is called Step-up transformer.

Step-down transformer

Converting low current value and the high voltage from the primary side of the step-up transformer to high current value and the low voltage from the secondary side of the step-down transformer is called a step-down transformer.

3-phase transformer

In a three-phase power system, 3-phase transformers use widely because they are more worthy and cost-effective than Single-phase transformers. It is advisable to use a three-unit single-phase transformer in the place of a single 3-phase transformer due to its size because the three-unit single-phase transformer is easy to transfer.

Distribution transformer

In the distribution transformer, the voltage steps down for distribution. The primary use is commercial or domestic uses. It is a suitable voltage regulator, but it does not operate at full load. It operates at a maximum of 50 % efficiency.

Instrument Transformers

The addition of PT (Potential Transformers) and CT (Current Transformers) reduces the high current value and voltages to lesser values. Conventional instruments measure this value.


If the ratio between high and low voltage sides is less than 2, the autotransformer is more cost-effective at this point.

Two winding transformer

If the ratio between high voltage and low voltage sides is more than 2, the two winding transformers are helpful.

Outdoor transformers

We can understand that these types of transformers are made for outdoor installation by the name Outdoor Transformers.

Indoor transformers

Similarly, you can understand that these types of transformers are made for indoor installation by Indoor Transformers.

Oil Cooled transformer

This type of transformer works on the cooling system built inside the transformer. The cooling medium used in oil-cooled transformers is transformer oil.

Dry-type transformer

This type of transformer works on the air-cooling system built inside the transformer. The cooling medium used in dry cooled transformers is natural air.

Uses of Power transformers

If electrical power has to generate at a low voltage level, the cost is high for this generation. Thus, the power transmission of the low voltage level takes place at the receiving end. If the low voltage power transmits in a higher current line, the outcome will be higher line losses.

It can cause ohmic losses in a system because if the power voltage level is high, the power current is low. Therefore, there is an issue in the system that reduces the capital cost or reduces the conductor’s cross-sectional area, which in the system further improves the voltage regulations. Due to this issue in the transformer, power of low-level voltage should step up that will provide effective transmission of electric power.

At the sending side of the power network, this process should work with the help of a step-up transformer. The direct distribution of high voltage power to the customer is impossible, so this power should be stepped down at the receiving end to the desired level using a step-down transformer. The power transformer plays a vital role in transmitting the power.

When the ratio of High voltage and Low voltage power is greater than 2, the two winding transformers are used commonly. When the ratio of High voltage and Low voltage power is less than 2, autotransformers are used because it is cost-effective.

In a 3-phase system, a three-unit 3-phase transformer is costlier than a single unit 3-phase transformer. The only drawback of a single unit transformer is that it is difficult to transport. And if one of the phase windings breaks down, then the whole part is removed from the service.

Power transformer functions depending on the mutual induction and operate on an Alternating Current Supply.


Thus, in this article, we have discussed so many types of transformers. We hope you would have enjoyed reading this article. Power Transformers Manufacturers India is still working on the advancement of transformers to provide us with excellent transformers.


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