What Are the Types of Transformers?

9 May 2023

Transformers play a crucial role in altering the voltage levels of an alternating current without changing its frequency. In other words, transformers are electrical machines that utilize the principle of electromagnetic induction to convert electrical energy into different voltage and current values at the same frequency for one or more circuits.

There are various types of transformers, including measurement transformers, auto-transformers, single-phase transformers, and three-phase power transformers. They are also categorized as distribution transformers, power transformers, high-voltage transformers, medium-voltage transformers, and step-up transformers.

Power Transformers: These are used in electronic circuits and various applications and are produced in two forms, dry-type and oil-filled type.

Distribution Transformers: They are used to reduce medium-voltage levels to lower levels for distribution purposes.

Auto-Transformers: These transformers have electrically interconnected primary and secondary windings and are used to provide adjustable voltage in low-power applications.

Control Transformers: Used to regulate voltage levels and phases at different points in the electrical system in circuits requiring constant voltage or current in VA ratings.

Audio Frequency Transformers: Used for impedance matching and processing in audio amplifiers with frequencies up to 20 kHz.

Isolation Transformers: Used for DC isolation purposes. When the primary voltage contains both AC and DC components, the secondary voltage contains only the AC component.

Measurement Transformers: Used in locations where high voltage and current levels are present to facilitate safe and accurate measurements. Measurement transformers reduce high voltage and current values to levels that measuring instruments can handle.

Transformers are also categorized based on their cores, cooling methods, and usage areas.

Based on Cores:

  • Core Type
  • Shell Type
  • Distributed Type
  • Ferrite Core Type

Based on Cooling Methods:

  • Oil-Immersed Transformers
  • Dry-Type Transformers

Based on Usage Areas:

  • Isolation Transformers
  • Feeder Transformers
  • Specific Transformers
  • Line Transformers
  • Impedance Transformers
  • Auto-Transformers
  • Pulse Transformers

These various types of transformers serve different purposes and are essential components in electrical systems and applications.