Types of Losses in a Transformer | Efficiency of Transformer


Types of Losses in a Transformer

The efficiency of an ideal transformer is very high and there are no losses of any kind. This means that the amount of energy we give at its input terminal is equal to its output terminal. That is why the input power and output power of an ideal transformer are equal and the energy loss is zero.

But in practice, this is not possible as it is due to losses in the transformer. This is a stable device as there are no moving parts in the transformer like a motor. So the mechanical damage of this cannot be observed but the electrical damage can be done as it contains copper and iron. So today we will see in our article how many types of losses occur in transformers.

Types of Losses in a Transformer:

The losses incurred in the transformer are as follows:

Sr. No. Types of Losses in a Transformer
#1. Iron Losses
#2. Copper Loss
#3. Stray Loss
#4. Dielectric Loss

There are many types of losses in transformers but some of them are important in such a way that there are many types of losses such as iron, copper, hysteresis, eddy, stray, and dielectric.

Copper loss is mainly due to the resistance of copper windings in it. While hysteresis occurs due to a change in magnetization inside the loss core.

Types of Losses in a Transformer

#1. Iron Losses in a Transformer:

Iron Losses are mainly due to the alternating current flowing in the transformer core. This loss is also called core loss as it occurs in the part of the core. This type of loss mainly depends on the magnetic properties of the material inside the transformer core.

The main part of the transformer is made with the help of iron hence this is also called iron loss. Iron/core These types of losses can be divided into two types, one is hysteresis loss and the other is eddy current loss.

#1.1 Hysteresis Loss:

Hysteresis Loss mainly occurs when the transformer core alternating current is applied then the magnetic field will be reversed. This type of loss depends on the material used in the manufacture of the transformer.

This is made possible by the use of high-quality materials to minimize such losses. Hysteresis damage can be minimized by using CRGO-cold-rolled grain-oriented C steel in general.

This can be represented with the help of the following equation.

Ph = Khf Bx m


‘Kh’ is the stability that depends on the quality and volume of the original material in the transformer.

‘BM’ is the highest flux density inside the core.

‘F’ is the alternating flux frequency otherwise supply.

‘X’ is the stability of Steinmetz and the value of this stability varies mainly from 1.5 to 2.5.

Also Read: Step-up Transformer | Construction | Working & Its Applications

#1.2 Eddy Current Loss:

Once the circuit is completed, EMF is induced in it and the transmission of power in the circuit is resumed. The value of the current usually depends on the sum of the e.m.f and the resistance in the area of ​​the circuit.

The main part of the transformer can be designed from an organized material. The flow of fluid in the emf can be provided in the body of the material. This current of current is known as eddy current.

This current will occur after experiencing a changing magnetic field in the conductor. The time this current is not responsible for performing any functional function is the time this current causes a loss within the magnetic material. This is why it is called eddy current loss which can be reduced by forming a core using slight laminations.

This can be represented with the help of the following equation.

Pe = KeBm2t2f2V watts


Ke’ eddy is the current co-efficient. This value is mainly based on the nature of the magnetic material, such as the resistivity and the quantity of the original material, and the width of the lamination.

Bm‘ is the highest rate of flux density in WB / m2.

T’ is the width of the lamination inside the meter.

F‘ is the inverse frequency of the magnetic field measured in Hz.

V’ is the amount of magnetic material in m3.

#2. Copper Loss:

Copper is damaged due to the ohmic resistance in the transformer winding. If the primary winding in the transformer is I1 and the secondary winding is I2 respectively, then the resistance of these windings is R1 and R2.

So the winding in which copper is lost is something like this I12R1 and I22R2 so all these losses will be of copper.

Pc = I12R1 + I22R2

Such loss is also called ohmic loss. This loss always varies depending on the load.

#3. Stray Loss:

This type of loss arises due to the presence of a leakage field in the transformer. This type of damage is less than copper and iron so it can be ignored.

#4. Dielectric Loss:

This type of loss occurs in the insulating material of the transformer as the transformer oil is an insulating material. For some reason, if this oil deteriorates or its quality deteriorates, it has a direct effect on the efficiency of the transformer.

The efficiency of the Transformer:

The definition of efficiency is the same as that of a normal electric machine, which can be obtained by the ratio of output power to input power. The formula is as follows.

Efficiency = output power / input power.

The transformer is a very efficient and highly efficient device. This device ranges from 95% to 98% of load efficiency.

When a transformer is highly efficient, its inputs and outputs are almost identical.

But his calculation from the above formula is not very reasonable.

But to find out its functionality, it is more appropriate to use the following formula.

Efficiency = (Input - Losses) / Input => 1 - (Losses / Iinput).

Let’s say the loss of copper is I2R1 while the loss of iron is Wi.

Efficiency = 1-loss / input.

= 1-I12R1 + Wi / V1I1CosΦ1
Ƞ = 1- (I1R1 / V1CosΦ1) iWi / V1I1CosΦ1

Distinguish the above equations with respect to ‘I1’.

d Ƞ / dI1 = 0- (R1 / V1CosΦ1) + Wi / V1I12 CosΦ1

‘Ƞ’ is at maximum d Ƞ / dI1 = 0

Therefore, the efficiency ‘‘ ’will be the maximum.

R1 / V1CosΦ1 = Wi / V1I12 CosΦ1
I12R1 / V1I12 CosΦ1 = Wi / V1I12 CosΦ1
I12R1 = Y

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