## Friday, January 5, 2024

How does a Transformer work - Working Principle electrical engineering

How does a transformer work. In this video we'll be looking at how a transformer works covering the basics with transformer working animations and explanations to understand the working principle. We'll cover how to create a magnetic field with electricity, Why only Alternating current can only be used in transformers, How a basic transformer works, step up and step down transformers, transformer connections and windings, Three phase transformers, Delta Wye connections.

What is a Transformer?

As the name suggests, an Electrical Transformer transfers electrical power from one electrical circuit to another electrical circuit. It does not change the value of power.

A Transformer only steps-up or steps-down the level of voltage or current.

A Transformer doesn’t change the circuit frequency during operation.

A Transformer works on the principle of electric i.e. mutual induction.

A Transformer operates when both circuits take effect by mutual induction.

A Transformer can’t step-up or step-down the level of DC voltage or DC Current.

A Transformer only step-up or step-down the level of AC voltage or AC Current.

A Transformer doesn't change the value of flux.

A Transformer won’t operate on DC Voltage.

Without transformers the electrical energy generated at generating stations won’t probably be sufficient enough to power up a city. Just imagine that there are no transformers. How many power plants do you think have to be set up in order to power up a city? It’s not easy to set up a power plant. It is expensive.

Numerous power plant have to be set up in order to have sufficient power. Transformers help by amplifying the Transformer output (stepping up or down the level of voltage or current).

When the number of turns of the secondary coil is greater than that of primary coil, such a transformer is known as step up transformer.

Likewise when the number of turns of coil of primary coil is greater than that of secondary transformer, such a transformer is known as step down transformer.

Working Principle of a Transformer

Transformer is a static device (and doesn’t contain on rotating parts, hence no friction losses), which converts electrical power from one circuit to another without changing its frequency. it Step up (or Step down) the level of AC Voltage and Current.

Transformer works on the principle of mutual induction of two coils or Faraday Law’s Of Electromagnetic induction. When current in the primary coil is changed the flux linked to the secondary coil also changes. Consequently an EMF is induced in the secondary coil due to Faraday’s law of electromagnetic induction.

The transformer is based on two principles: first, that an electric current can produce a magnetic field (electromagnetism), and, second, that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil (electromagnetic induction). Changing the current in the primary coil changes the magnetic flux that is developed. The changing magnetic flux induces a voltage in the secondary coil.

A simple transformer has a soft iron or silicon steel core and windings placed on it (iron core). Both the core and the windings are insulated from each other. The winding connected to the main supply is called the primary and the winding connected to the load circuit is called the secondary.

Winding (coil) connected to higher voltage is known as high voltage winding while the winding connected to low voltage is known as low voltage winding. In the case of a step up transformer, the primary coil (winding) is the low voltage winding, the number of turns of the windings of the secondary is more than that of the primary. Vice versa for step down transformer.

When the primary winding is connected to ac mains supply, a current flows through it. Since the winding links with the core, current flowing through the winding will produce an alternating flux in the core. EMF is induced in the secondary coil since the alternating flux links the two windings. The frequency of the induced EMF is the same as that of the flux or the supplied voltage.

By so doing (variation of flux) energy is transferred from the primary coil to the secondary coil by means of electromagnetic induction without the change in the frequency of the voltage supplied to the transformer. During the process, a self-induced EMF is produced in the primary coil which opposes the applied voltage. The self induced EMF is known as back EMF.

Ideal Transformer verses Practical Transformer

In our previous post, we have discussed the ideal transformer with phasor and circuit diagrams and detailed comparison with practical transformers. Keep in mind that an ideal transformer has no losses at all e.g. The input power to the transformer is equal to the output power. In addition, it should be noted that ideal transformer is an imaginary (theoretical concept) which does not exist in real life.

How does a Transformer work - Working Principle electrical engineering

How does a transformer work. In this video we'll be looking at how a transformer works covering the basics with transformer working animations and explanations to understand the working principle. We'll cover how to create a magnetic field with electricity, Why only Alternating current can only be used in transformers, How a basic transformer works, step up and step down transformers, transformer connections and windings, Three phase transformers, Delta Wye connections.

What is a Transformer?

As the name suggests, an Electrical Transformer transfers electrical power from one electrical circuit to another electrical circuit. It does not change the value of power.

A Transformer only steps-up or steps-down the level of voltage or current.

A Transformer doesn’t change the circuit frequency during operation.

A Transformer works on the principle of electric i.e. mutual induction.

A Transformer operates when both circuits take effect by mutual induction.

A Transformer can’t step-up or step-down the level of DC voltage or DC Current.

A Transformer only step-up or step-down the level of AC voltage or AC Current.

A Transformer doesn't change the value of flux.

A Transformer won’t operate on DC Voltage.

Without transformers the electrical energy generated at generating stations won’t probably be sufficient enough to power up a city. Just imagine that there are no transformers. How many power plants do you think have to be set up in order to power up a city? It’s not easy to set up a power plant. It is expensive.

Numerous power plant have to be set up in order to have sufficient power. Transformers help by amplifying the Transformer output (stepping up or down the level of voltage or current).

When the number of turns of the secondary coil is greater than that of primary coil, such a transformer is known as step up transformer.

Likewise when the number of turns of coil of primary coil is greater than that of secondary transformer, such a transformer is known as step down transformer.

Working Principle of a Transformer

Transformer is a static device (and doesn’t contain on rotating parts, hence no friction losses), which converts electrical power from one circuit to another without changing its frequency. it Step up (or Step down) the level of AC Voltage and Current.

Transformer works on the principle of mutual induction of two coils or Faraday Law’s Of Electromagnetic induction. When current in the primary coil is changed the flux linked to the secondary coil also changes. Consequently an EMF is induced in the secondary coil due to Faraday’s law of electromagnetic induction.

The transformer is based on two principles: first, that an electric current can produce a magnetic field (electromagnetism), and, second, that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil (electromagnetic induction). Changing the current in the primary coil changes the magnetic flux that is developed. The changing magnetic flux induces a voltage in the secondary coil.

A simple transformer has a soft iron or silicon steel core and windings placed on it (iron core). Both the core and the windings are insulated from each other. The winding connected to the main supply is called the primary and the winding connected to the load circuit is called the secondary.

Winding (coil) connected to higher voltage is known as high voltage winding while the winding connected to low voltage is known as low voltage winding. In the case of a step up transformer, the primary coil (winding) is the low voltage winding, the number of turns of the windings of the secondary is more than that of the primary. Vice versa for step down transformer.

When the primary winding is connected to ac mains supply, a current flows through it. Since the winding links with the core, current flowing through the winding will produce an alternating flux in the core. EMF is induced in the secondary coil since the alternating flux links the two windings. The frequency of the induced EMF is the same as that of the flux or the supplied voltage.

By so doing (variation of flux) energy is transferred from the primary coil to the secondary coil by means of electromagnetic induction without the change in the frequency of the voltage supplied to the transformer. During the process, a self-induced EMF is produced in the primary coil which opposes the applied voltage. The self induced EMF is known as back EMF.

Ideal Transformer verses Practical Transformer

In our previous post, we have discussed the ideal transformer with phasor and circuit diagrams and detailed comparison with practical transformers. Keep in mind that an ideal transformer has no losses at all e.g. The input power to the transformer is equal to the output power. In addition, it should be noted that ideal transformer is an imaginary (theoretical concept) which does not exist in real life.