What Is The Power Transformer?

1. What is the power transformer?

Power transformers transform electrical voltage from one level or phase to another. Typically, it steps down the voltage ratio from a higher to a lower level. Like other transformers, power transformers work on the magnetic induction principle between coils to convert voltage or current levels to another voltage or current levels. It includes a broad range of electrical transformers, such as control transformer, autotransformer, current transformer, general-purpose transformer, distribution transformer, instrument transformer, potential (voltage) transformer, and isolation transformer.

There are some differences between power transformers and distribution transformers operating at normal levels. Usually, power transformers are utilities in electric transmission networks (that use higher voltages) for either step up or step down applications (400 kV, 200 kV, 110 kV, 66 kV, 33kV), and their capacity is higher than 200MVA. Utility distribution transformers are put to work in distribution networks to transform electricity to a level (11kV, 6.6 kV, 3.3 kV, 440V, 230V) that can be utilized by an end-user and usually are rated lower than 200MVA.

2. Types of the power transformer

There are many ways to classify power transformers according to its function as well as its structure.

• Based on the number of the phase, we will divide into single-phase transformers and three-phase transformers.
• Based on the function, there are Step-up transformers and Step down transformer
• According to the core, we divide into Air core Transformer and Ferromagnetic/Iron Core Transformer.
• According to the usage: power transformers, distribution transformer, Isolation transformer
• Based on windings, we have Two Winding Transformer and Autotransformer.
• Based on core design, we have Core Type Transformer, Shell Type Transformer, and Berry Type Transformer.

3. Functions and roles of transformers: 

A transformer is an electrical device consisting of two or more windings, which are connected in the same magnetic field. A transformer consists of two or more insulated copper coils wound up on the same ferrite or ferromagnetic core. These iron cores do not conduct electricity, but they are magnetic conductivity.

Transformer roles

The power transformers can change the alternating voltage, increase or decrease the voltage, giving the output voltage corresponding to the needs. It's used to transfer electricity to long distances or put them into use in homes or factories.

So, you can't use your electricity without a power transformer.

More specific

The role of a transformer is it converts the voltage to the desired purpose, for example, from a 10 kV medium-voltage line to a low voltage 220 V or 400 V used in residential activities or factories.

Moreover, power transformers convert the medium voltage from the source (10 kV to 50 kV) to a high voltage (110 kV to 500 kV or higher) before transmitting it to the high voltage line. In power transmission over long distances, the higher the voltage, the less loss.