In this article, we will look into a special type of transformer known as the Ideal Transformer which is designed in ideal condition with no loss and 100% efficiency. We will discuss what is a transformer, ideal transformer. We will look into the working principle, properties, and equations of the ideal transformer. We will also look into an ideal transformer with load and with no load. In addition to these, we will also see the phasor diagram. Later, we will discuss the advantages, disadvantages, and applications of, the ideal transformer.

What is a Transformer?

A transformer is a device that transfers electrical energy between two or more circuits. It is used for AC and is used for changing the voltage without changing the frequency. These types of transformers are known as step-up and step-down transformers. It uses the principle of electromagnetic induction for the transfer of energy. Transformers typically consist of two coils of wire these are known as primary and secondary windings.

Ideal Transformer

An Ideal Transformer is a type of imaginary transformer used as a theoretical approach to analyze the behavior of real transformers. This transformer does not have any loss of power, so the efficiency is 100%.In an Ideal Transformer, there is no leakage flux which means that the magnetic flux generated by the Primary winding will be linked with the secondary will have no loss. Also, an ideal transformer operates without magnetic saturation, maintaining linear magnetic properties regardless of the applied voltage or current.

Ideal Transformer

Working Principle

Ideal Transformer is based on the principle of electromagnetic induction. The primary and secondary windings are wrapped around a common magnetic core. When the current flows through the primary winding, a magnetic field is created. This magnetic field induces a voltage in the secondary winding.

Equations of Ideal Transformer

In ideal transformer, as there is no loss and has 100% efficiency. Therefore, input power will be equal to output power. We can write it as,

[Tex]E_2I_2\cos\phi=E_1I_1\cos\phi \newline => \frac{E_2}{E_1}=\frac{I_1}{I_2}[/Tex]

We can write the conversion ratio as,

[Tex]\frac{V_2}{V_1}=\frac{E_2}{E_1}=\frac{N_2}{N_1}=\frac{I_1}{I_2}=K[/Tex]

Ideal Transformer With Load

Ideal transformer with load is a type of transformer where a load is connected to secondary winding of the ideal transformer. When current flows through the secondary section a magnetic field is created around it, by the principle of electromagnetic induction the changing magnetic field induces a voltage in the primary part of the transformer. The ratio of number of turns in the primary to the number of turns in the secondary part will determine the ratio of voltage in the primary and secondary part.

Ideal transformer with load

Let’s consider a load of [Tex]Z_L[/Tex] is connected to the secondary part of the transformer. This will induce an EMF E₂ along with current I₂.

So, we can write, [Tex]I_2=\frac{E_2}{Z_L}=\frac{V_2}{Z_L}[/Tex].

([Tex]E_2=V_2[/Tex] in case of ideal transformer)

I₂ current flowing in the secondary part creates a magnetomotive force. This force produces a flux which is in the opposite direction of the main flux. This flux will make some changes in the core flux. to counterbalance the flux the primary current should be,

[Tex]N_1I_1=N_2I_2 \newline \Rightarrow I_1=\frac{N_2}{N_1}*I_2[/Tex]

Phasor Diagram

The phasor diagram of the ideal transformer with load is given below where, the current I₂ will lag behind the EMF E₂ because we assumed the load to be inductive. The lagging angle will be [Tex]\phi_2[/Tex] . Also, we will not consider the load current as the transformer is in ideal condition.

Ideal Transformer With No Load

In this type of ideal transformer there is no load connected to the secondary part of the transformer hence, no current flows through this part. As there is no current in the secondary part, no voltage is induced in the primary part. The current that flows through the primary part is the magnetizing current that is required to establish the magnetic field in the core of the transformer. The primary current is due to the applied voltage and the inductance of the primary coil.

Ideal transformer with no load

An input voltage [Tex]V_1[/Tex] is given to the primary winding of the transformer because of which a small magnetizing current [Tex]I_m[/Tex] flows through the primary winding. This current produces a flux which induces [Tex]E_1\: \: and \:\: E_2[/Tex] in primary and secondary respectively.

Phasor Diagram

As the current in the secondary winding is zero, there is only magnetizing current which lags 90⁰ of the input voltage V₁. The induced EMFs E₁ and E₂ are inversely proportional to the input voltage.

Properties of an Ideal Transformer

• The windings have very small or no resistance.
• As there is no resistance there will no loss.
• The efficiency will be 100%.
• There will be perfect coupling between the primary and secondary windings.
• There will no core loss from eddy currents and hysteresis loop.
• There will be no leakage flux.
• This is a perfect linear device.

Advantages of Ideal Transformer

• Ideal transformer is 100% efficient and thus have zero power wastage.
• They are easy to model, can be used to simplify and analyze complex transformer designs.
• They are useful in isolating the input and output circuits so as to avoid grounding.
• It can be used for power transformation like step up and step down transformers.

Disadvantages of Ideal Transformer

• This case is only theoretically possible and isn’t true in real world or practical applications.
• As it has no loss, so analysis of loss conditions can’t be done.
• Ideal transformers has a limited frequency range and it can’t be used to study the behavior of large frequencies.
• It is assumed to have perfect coupling but in reality there is leakage flux which reduces the efficiency.

Applications of Ideal Transformer

• Ideal transformers are used to analyze the behavior of the practical transformer, as there is no loss and leakage of flux it easier to analyze.
• Ideal transformers are used for analysis of step-up and step-down transformer’s performance. Thus they are used for voltage transformation.
• This type of transformer are used to transmitting electricity at long ranges by stepping up the voltage of the transformer.
• It is used for coupling of signals which is used in audio and telecommunications.
• They are used of isolation of circuits to prevent it from grounding.
• The conversion ratio is used for voltage regulation in transformers.

Conclusion

In conclusion, Ideal transformer is a theoretical concept that is used to analyze the behavior of the transformer. This transformer has 100% efficiency and zero loss. This is very much useful for understanding the basic principles of the transformer. Although it is useful for understanding and analyzing the practical transformer operation differs from it. In practical applications there is losses, flux leakage and many other factors that are needed to be considered.

Ideal Transformer – FAQs

Which law is used in Transformer?

Faraday’s law of electromagnetic induction is used in the working principle of the transformer. According to this law, the induced EMF is equal to the rate of change of the magnetic flux in the circuit

What is rating in transformer?

Rating species the maximum power that the transformer can handle. It is given in kVA(Kilovolt-amperes).

What is the efficiency of a transformer?

The ratio of output power to input power is known as efficiency of the transformer.