Parts of Transformer and Their Functions: A Comprehensive Guide

Transformers are an essential part of the power grid, enabling the efficient transmission of electrical energy over long distances. They are made up of several components, each with its specific function. In this article, we will explore the various parts of a transformer and their functions in-depth.

Table of Contents

1. Introduction
2. Transformer Core
   1. Core Material
   2. Laminations
   3. Winding
3. Transformer Windings
   1. Primary Winding
   2. Secondary Winding
   3. Tertiary Winding
4. Transformer Tanks
   1. Material
   2. Purpose
5. Transformer Cooling System
   1. Types of Cooling System
   2. Function
6. Transformer Tap Changer
   1. Function
   2. Types of Tap Changer
7. Transformer Breather
   1. Function
   2. Types of Breather
8. Transformer Bushing
   1. Function
   2. Types of Bushing
9. Conclusion
10. FAQs

Introduction

Transformers are electrical devices that transfer electrical energy from one circuit to another, using electromagnetic induction. They can be used to step up or step down voltage levels, depending on the application. A transformer consists of two or more windings that are wound around a magnetic core. The windings are insulated from each other and the core, and they are connected to the electrical circuit. Let’s take a closer look at the various parts of a transformer and their functions.

Transformer Core

The core is the central part of the transformer, and its primary function is to provide a path for the magnetic flux. The core is made up of core material and laminations.

Core Material

The core material is typically made of steel, and it is chosen for its high magnetic permeability and low hysteresis loss. The steel is usually coated with an insulating material to prevent eddy currents.

Laminations

The core is constructed using laminations, which are thin sheets of steel that are stacked together. The laminations are insulated from each other using an insulating coating. This construction reduces eddy currents and hysteresis loss.

Winding

The winding is the copper conductor that is wound around the core. It is insulated from the core using an insulating material. The winding consists of primary, secondary, and tertiary windings.

Transformer Windings

The windings are the conductive coils that are wrapped around the core. There are usually two or three windings in a transformer, each with its specific function.

Primary Winding

The primary winding is the coil that receives the input voltage. When the voltage is applied to the primary winding, it creates a magnetic field around the core, which induces a voltage in the secondary winding.

Secondary Winding

The secondary winding is the coil that delivers the output voltage. It is connected to the load circuit and transforms the input voltage to the desired output voltage.

Tertiary Winding

The tertiary winding is an additional winding that is sometimes used in transformers. It is used to stabilize the voltage and reduce harmonic distortion.

Transformer Tanks

The transformer tank is the outer covering that protects the transformer from the environment. It is typically made of steel or aluminum and is designed to withstand the pressure generated by the cooling system.

Material

The tank is usually made of steel or aluminum, which are both strong and durable materials.

Purpose

The tank’s primary purpose is to protect the transformer from the environment, including weather, dirt, and moisture.

Transformer Cooling System

The transformer generates heat during operation, which can cause the winding insulation to deteriorate over time. Therefore, it is essential to dissipate the heat generated by the transformer. This is where the cooling system comes in.

Types of Cooling System

There are two types of cooling systems used in transformers: oil-immersed cooling and air-cooled cooling.

Oil-Immersed Cooling

In this type of cooling system, the transformer is immersed in oil, which acts as a coolant. The oil absorbs the heat generated by the transformer and dissipates it through the tank’s surface.

Air-Cooled Cooling

In this type of cooling system, air is used as a coolant. The transformer is equipped with cooling fins or tubes, which increase the surface area exposed to air. The heat is then dissipated through the cooling fins or tubes.

Function

The cooling system’s primary function is to dissipate the heat generated by the transformer, preventing the winding insulation from deteriorating over time.

Transformer Tap Changer

The tap changer is a device used to adjust the transformer’s output voltage. It is located on the high-voltage winding side of the transformer.

Function

The tap changer’s primary function is to adjust the transformer’s output voltage, enabling it to be compatible with the load’s voltage requirements.

Types of Tap Changer

There are two types of tap changer: on-load tap changer (OLTC) and off-load tap changer (OLTC).

On-Load Tap Changer

In this type of tap changer, the voltage is adjusted while the transformer is in operation.

Off-Load Tap Changer

In this type of tap changer, the transformer is disconnected from the load before the voltage is adjusted.

Transformer Breather

The breather is a device used to regulate the air entering and leaving the transformer tank.

Function

The breather’s primary function is to maintain the air inside the transformer tank dry and clean, preventing the transformer oil from oxidizing and deteriorating over time.

Types of Breather

There are two types of breather: silica gel breather and oil-sealed breather.

Silica Gel Breather

In this type of breather, the silica gel absorbs moisture from the air entering the transformer tank, preventing it from oxidizing the transformer oil.

Oil-Sealed Breather

In this type of breather, the air entering the transformer tank is filtered through a dehydrating breather, which removes moisture and impurities from the air.

Transformer Bushing

The bushing is a device used to insulate the transformer’s electrical connection points.

Function

The bushing’s primary function is to insulate the transformer’s electrical connection points, preventing electrical current from escaping or entering the transformer.

Types of Bushing

There are two types of bushing: oil-impregnated paper bushing and resin-impregnated synthetic bushing.

Oil-Impregnated Paper Bushing

In this type of bushing, the insulating material is impregnated with oil to increase its insulating properties.

Resin-Impregnated Synthetic Bushing

In this type of bushing, the insulating material is impregnated with synthetic resin to increase its insulating properties.

Conclusion

Transformers are an essential part of the power grid, enabling the efficient transmission of electrical energy over long distances. The various parts of a transformer, including the core, winding, tank, cooling system, tap changer, breather, and bushing, all play crucial roles in ensuring the transformer’s optimal performance. Understanding these parts and their functions is crucial for anyone working with transformers.

FAQs

1. What is a transformer core made of?

A transformer core is typically made of laminated sheets of magnetic material, such as iron or steel.

2. How does the transformer winding work?

The transformer winding works by inducing an electromotive force (EMF) in the secondary winding when a current is applied to the primary winding.

3. What is the purpose of the transformer tank?

The transformer tank serves as a protective casing for the transformer, as well as a container for the insulating oil used in the transformer.

4. Why is the cooling system important in a transformer?

The cooling system is important in a transformer because it dissipates the heat generated by the transformer, preventing the winding insulation from deteriorating over time.

5. What is the function of the transformer breather?

The transformer breather maintains the air inside the transformer tank dry and clean, preventing the transformer oil from oxidizing and deteriorating over time.