Significance of Different Types of Transformers According To Their Application

Transformer is an electronic device that generates and converts power supply from one circuit to another without changing its frequency. It works on the principle of electromagnetism discovered by Michael Faraday. In the previous article, we discussed many aspects of transformers. Here extending the significance of different types of transformers as per their application.

We can observe the application of transformers at every level but their significance varies as per the usage like the voltage, size, core material, and so on.

Transformer Types based on Voltage:

If we talk about the complexity of transformer manufacturing, there is no electrical connection from one side to another. But, the two electrically independent coils conduct electricity by electromagnetic flux. A transformer can have multiple coils or windings on any side - primary or secondary. In many cases, transformers have multiple primary sides connected in series called center-tapped, which you can also observe on the secondary side.

Transformers are manufactured to convert the voltage level of the primary side to the secondary side. Based on the voltage level, transformers are further classified into three categories Step Up, Step Down, and Isolation Transformers.

1. Step-up: Step-up transformers increase low voltage to high secondary voltage which is achieved by the ratio of primary and secondary winding ratio (less than 1). In step-up, the number of turns in secondary windings is always higher than in the primary winding. 
2. Step-down: A step-down transformer converts the primary voltage level to a lower voltage across the secondary output. It is also achieved by the ratio of primary and secondary windings and is always more than 1. 
3. Isolation Transformer: Isolation transformers do not convert voltage from primary to secondary windings. The primary and secondary voltage always remains the same because their winding ratio is always equal to 1. 

Transformers based on Core Material:

A transformer transfers energy by conducting electromagnetic flux through a core material. Different core materials produce electromagnetic fluxes with different efficiency. Based on materials, transformers are classified as Iron-Core Transformers, Ferrite Core Transformers and Toroidal Core Transformers. 

• Iron-core Transformer: In iron-core transformers, the core material of multiple soft iron plates is used with different shapes and sizes like E, I, U, and L. The efficiency of iron core transformers is very high due to the excellent magnetic properties of iron.
• Ferrite Core Transformer: In Ferrite Core Transformers, ferrite core is used due to its high magnetic permeability. It offers very low losses in high-frequency applications such as in SMPS (switch mode power supply) or RF-related applications.
• Toroidal Core Transformer: The toroidal core transformer uses toroid-shaped core material, such as iron core or ferrite core. Toroids are ring or donut-shaped core materials and are widely used for superior electrical performance. The leakage inductance is low and offers very high inductance and Q factors.
• Air Core Transformer: The air core transformers do not use any physical magnetic core but entirely use the air. The primary coil is supplied with alternating current that produces an electromagnetic field around it (as per the Faraday Law of Induction). It produces low mutual inductance compared to iron or ferrite core. These types of transformers are used in radio frequency-related applications, wireless charging solutions, and portable electronics.

Transformer based on Winding Arrangement:

Auto Winding Transformer:

In an Auto-winding transformer, the coils can be connected in series while the center tapped node is movable. Although, depending on the center tapped position, the secondary voltage can be varied.

Transformers based on Usage:

Power Domain:

In Power Domain, the transformers deal with power generation, measurement, and distribution. Accordingly, it is classified into three main categories i.e. Power Transformer, Measurement Transformer, and Distribution Transformer.

• Power Transformers:

The power transformers convert the low voltage high current to high voltage low current, required to minimize the power loss in the power distribution system. They are large and act as the power generator in the primary distribution grid. Power transformers work on the availability of the phase, typically in a three-phase system. However, power transformers work in single phase and are less efficient. Whereas, three-phase transformers are costly but more efficient than single-phase power transformers. The Power transformers are different from three-phase transformers in terms of usage.

• Distribution Transformers:

Distribution transformers are deployed in the last phase of the power distribution system. These step-down transformers convert high grid voltage to the end customer's required voltage. Their size varies from smaller to larger and can be used in single-phase or three-phase. Based on isolation, it can further be classified as dry-type transformers or liquid-immersed. The transformers are mostly constructed in a C shape using laminated steel plates.

In the upcoming blog we will further get to know the difference between power transformer and three phase transformer in terms of usage.

How Power Transformers are different from Distribution Transformers in Terms of Usage