# Transformer Losses | Core loss | Copper loss

what are Transformer Losses?

The transformer is a fixed type device. Therefore, there is no wastage due to friction. Transformer loss refers to all that can be seen in no-load and full-load conditions.

## Core loss in a transformer (Core loss)

### Eddy current lossHysteresis lossHysteresis and Eddy current lossesEddy current loss in transformerWhen the current flowing through the coil of an electromagnet changes. Then the magnetic field around it also changes This variable flux cuts the wire of the coil, creating voltage in the coil This flux also cuts the same core As a result,a current is also rotated in this core, called eddy current The core resistance is interrupted when the eddy current flows through the core material. The waste that causes it is called eddy current loss.Eddy current loss formulaP_C=K_ef^2B_m^2t^2----(1)K_e= The number of constant. It depends on the size of the core used, the thickness of the lamination, and the resistivity of the steel (core)f= Frequencyt= The lamination is thickSetting the value of flux density to Bm in Equation 1\Rightarrow P_C=K_ef^2t^2(\frac{E^2}{f^2})=K_2t^2E^2Ways to reduce Eddy ​​current lossThis loss can be reduced by using a thin core of bright resistive magnetic material.Hysteresis LossThe variable current changes direction every half cycle As a result, the magnetic flux changes periodically to the maximum positive meaning once and the maximum negative value again.This periodic change of positive mean and negative mean causes the core magnets to change direction again and again.Power is expended as a result of so much collision. This expended energy appears as heat, this is called hysteresis loss.Hysteresis loss formula\Rightarrow P_h=K_hfB_m1.6W--------(1)K_h= The number of constant. It depends on the size and quality of the core usedB_m=The maximum flux density of the core f= Frequency

We know,
E=4.44fN\phi_m\times10^{-8}
\phi_m=B_m\times A=\frac{E\times10^8}{4.44fN}
B_m=(\frac{10^8}{4.44NA})\frac Ef
A = Area of the core

The N and A constants of the transformer
B_m=K\frac Ef \lbrack K=\frac{10^8}{4.44NA}\rbrack

Let's put this into equation 1,

\Rightarrow P_h=K_hfk(\frac{E^{1.6}}{f^{1.6}})=K_1(\frac{E^{1.6}}{f^{1.6}})-----------(2)

Ways to reduce hysteresis loss: -
This loss can be reduced by using a high-quality magnetic steel core.

Effects of hysteresis loss: -
The higher the hysteresis loss, the more heat will be generated As a result power loss will increase and insulation will be more damaged.

### Copper loss in transformer(Copper loss)

The loss due to the ohmic resistance of the primary and secondary windings of the transformer is called copper loss.

Copper loss is related to the load. As the load increases, its loss increases. A loss is determined by I^2R. Copper loss is proportional to the square of the current.

#### Copper loss formula

That is,

P_C\sim I^2

P_C\sim KVA^2

The amount of copper loss is found from the short circuit test. In the case of the transformer, copper is lost at winding. In that case total copper loss = {I^2}_PR_P+{I^2}_SR_S
If the load is less or more than the rated KVA of the transformer, the copper loss decreases or increases very fast.

For example - a transformer rated KVA will have 100W, copper loss at ½ load, ¾ load and double load at copper loss respectively.
\Rightarrow\{0.5\div1\}^2\times100=25W
\Rightarrow\{(3\div4)\div1\}^2\times100=56.25W
\Rightarrow(2\div1)^2\times100=400W

Copper loss Two types: -

Copper loss in the primary winding

Copper loss in the secondary winding

### Q1.What is Eddy Current Loss?

Ans: The dissipation caused by the core resistance when the current flows through the core is called, Eddy current loss.

#### Q2.How to reduce the hysteresis loss of the transformer?

Ans: Uses high-quality magnetic seat cores.