losses in transformer

In transformer there are different types of  losses are occurred which reduce the efficiency of transformer.If there is any loss in transformer than there will be no transfer of 100% electrical energy from primary to secondary of coil.There are following types of losses occur is transformer given as below

  • Iron Losses
  • Copper Losses

Iron Losses

Transformer core is made up by the soft iron and when transformer start working then due to Faraday's law there will be transfer of electrical energy in form of magnetic flux.This will also leads to loss in iron core.This is termed as iron losses.Iron losses is further of two types given as below

  • Eddy Current Loss
  • Hysteresis Loss

Eddy Current Loss

In Transformer we know it consist of two coils primary and secondary and when input supply is ON there will change in magnetic flux linked with the coil as per Faraday's Law of electromagnetic induction when change in magnetic flux linked with coil then there will be production of induced emf in coil and same will pass to another coil through core.The current which is produced due to this effect is called as eddy current and we know where is current there is I square R losses will be occur.

So same in case of transformer when eddy current flow power loss is occur in form of heat.This type  of loss is called as Eddy Current loss.

Eddy current loss is minimized by using the laminated core in transformer.

Hysteresis Loss

Hysteresis loss is which is occurred due to frequent change in current and voltage in transformer.In ferromagnetic material there is friction in molecules occur and this results in  Hysteresis Loss.

To understand Hysteresis Loss we need to understand the B&H where B is intensity of magnetization and H is magnetic field density.

When the magnetic force is completely zeroed, it still has magnetic force in the ferromagnetic materials, which we call residue magnetism, and display it from point P, this residue magnetism is completely To finish it, a magnetic force has to be applied in the opposite direction.

The force exerted in the opposite direction to eliminate residue magnetism is called coercive force.

When it ceases magnetism, then it displays the force acting in the opposite direction from point C.
By increasing this force further in the opposite direction, the piece of ferromagnetic materials becomes magnetized in the opposite direction to its saturation point which we display from D.

When the magnetic force value is 0 again, the residue in the piece of ferromagnetic materials remains magnetism, which is represented by point E,
By applying more magnetic force, the magnetic density, ie, the value of magnetic force is reduced to zero, which is represented by point F, and on applying more force it again moves to point A.

In this way, ABCDEF creates a loop, which we call hysteresis Loop.
The larger the area of ​​the loop, the greater the hysteresis loss and the lower the area of ​​the loop, the lower the hysteresis loss.The transformer adds 3% to 5% silica to its core to reduce hysteresis loss, thus the core made of silicon steel.


Retentivity is a property magnetic material to retain magnetism even if magnetic field is not present.


Coercivity is amount of magnetic field density required to make magnetism to zero is called as coercivity. 

Copper Loss

This type of losses occurred due to resistance of coil winding in transformer when current is flowing through winding it will leads to I square R losses in transformer it is termed as copper losses.Copper losses are only occurred when there is any load is connected to transformer without load copper losses are zero.

We hope friends you will understand above article if you have any query please comment.

Post a Comment