 # The Operation Of An Electrical Transformer

The objective of this post is to explain: The Operation Of An Electrical Transformer

By the end of this post you’ll have a better understanding of the following topics:

• General overview of transformers
• Principle of operation
• Transformer application
• Single-phase transformers
• Three-phase transformers
• Transformer calculations
• Power transmission losses
• Core & Shell transformers
• Transformer cooling
• Autotransformers

The Information not covered in the post below includes:

• Instrument transformers

## Electrical Transformers Overview Video #1

Video Source: Learn Engineering.Org

#### Video Highlights:

Provides an overview of the function of a transformer.

Describes & Illustrates

• The principle of operation for a transformer “Electro Magnetic Induction”.
• The working and construction of single phase and a 3-phase transformers.
• How the mathematical equation is derived for voltage calculations of a step-up and step-down transformer.
• The 3-Phase transformer coil configuration and disc type windings.
• How low voltage windings, are connected in the delta configuration. High voltage windings, are connected in the star configuration.
• High voltage insulated bushings to bring out the electrical energy of the 3-phase transformer.
• The core of the transformer, describing the construction of thin insulated steel lamination’s, showing them stacked together to form three phase limbs. Then describe the purpose of the thin laminations.
• Potential energy losses while transferring power from the primary to secondary coil.
• The transformer being immersed in cooling oil to dissipate the heat.
• How the oil dissipates the heat from the transformer through natural convection with radiator fins.
• Conservator tank to accommodate for changes in the volume of oil due to temperature changes.

## Electrical Transformers Overview Video #2

Video Source: Public Resource.Org

#### Video Highlights:

Provides an overview of the function of a transformer.

#### Describes & Illustrates

• Every day devices, which use transformers to operate correctly.
• Step-Down transformers.
• Step-Up transformers.
• Left Hand Rule.
• Electromagnetic Induction.
• Turns Ratio.
• Power Transmission Calculations.
• Coefficient Of Coupling (K).

#### Type Of Transformers

• Power Transformers
• Audio Transformers
• Auto Transformers

## Electrical Transformer Windings Overview

Video Source: Learn Engineering.Org

#### Video Highlights:

Describes & Illustrates

• The principle of operation for transformer windings.

The following type of windings used in transformers.

• Helical Windings
• Cross-Over Windings
• Disc Type Windings
• Sandwich Windings

## Electrical Transformer Core Types Overview

Video Source: Learn Engineering.Org

#### Video Highlights:

Describes & Illustrates

• The principle of operation for a transformer cores.
• The construction and operation of single phase and three phase core type transformers.
• The construction and operation of Shell and Core Type transformers.
• Explains the advantages and disadvantages when comparing Shell and Core Type transformers.

## The Operation Of An Electrical Transformer Voltage Calculations Overview

The formula, description of the formula variables, and practice calculations provided below will help you understand how to determine the primary and secondary voltage calculations with various primary and secondary winding turn configurations.

## Formula

Because the voltage in each winding is proportional to the number of turns in each winding, it can be expressed mathematically as follows: ## Formula Variables

The variables used in the formulas provided above to are defined as follows:

Ep = Voltage primary

Es = Voltage secondary

Np = Number of turns in primary

Ns = Number of turns in secondary

## Practice Electrical Transformer Voltage Calculations

Practice calculations will be uploaded shortly.

How Does A Transformer Work Practice Transformer Voltage Calculations #1

How Does A Transformer Work Practice Transformer Voltage Calculations #2

## Summary

Note: These are the videos and calculations I recommend completing, to obtain a better understanding of How Do Electrical Transformers Work.

What videos do you recommend?