Concept of magnetization current

[panda1234]

Hi,
I know what is magnetization current but didn't realize that.what is it's concept?why we called that magnetization current?and why that has about -pi/2 phase?

 

[--BawA--]

Magnetizing current establishes the magnetic field in the inductor.As you know that the average voltage across any inductor is 0 . so during -ve half cycle, the magnetizing inductance reverse the polarity across your inductor/trafo .
Magnetizing Current lags Voltage by 90 degrees .
The inductor act as a high impedance element when there is a change in voltage .
Z=2*pi*F*L

 

[panda1234]

Thanks but i want to explain it in Transformer.

 

[--BawA--]

Same theory applies on transformer also.

 

[chuckey]

If you have a "perfect" transformer and apply voltage to its primary then no current flows because there is no secondary current. This means that the impedance of the primary is infinite. In a real world transformer, the primary impedance is not infinite, so a current flows.This current is due to the primary inductance, so the current lags the applied voltage by 90 degrees and is the magnetising current.
Frank

 

[RajivConfident]

The magnetising current is that current which flows in the primary winding when the primary voltage is applied with the secondary unloaded.
It's the necessary current that satisfies the excitation condition as determined by the fundamental transformer equation.
This current is related (with a reasonably good approximation) to the transformer equivalent primary inductance value and the applied primary voltage and given source frequency.
Magnetising current flows into the primary irrespective of transformer load condition.