What operational characteristics it will show?
Core saturation could be positive or negative, above knee point, of B-H curve of core material, depending on residual magnetic flux in the core, and will produced inrush current pattern when switch on. Modern CRGO Used core working on higher flux density, reduced the core volume(size) considerably, with the distorted voltage wave of higher harmonics. Refer my research papers, methods to generating inrush current patterns...........
It means that the core flux stops increasing with increasing primary "magnetizing current".
For transformers to work properly, the flux needs to be continuously changing.
Its the changing flux that causes voltage to be induced at the secondary winding.
Its important to say "magnetizing current", because "load current" has little affect on core flux.
Dear Salah,
assuming you're operating a typical transformer to convert a sinusoidal input voltage into a sinusoidal output voltage, saturation of the core will have two most prominent effects:
1) as described by Bhupendra, the linearity of the transformer is disturbed, leading to clipping - flat tops at the output voltage tips - which will induce unwanted harmonic distortion to the output.
2) the loss-situation for the transformer changes leading to increased temperatures in the core which, at some point, may lead to damage to the transformer
Assuming you consider a ferroresonant transformer, saturation of the core is a method of magnetically stabilizing the output voltage.
If done properly, the input voltage may vary by +/-50% while the output voltage only changes by +/-5%. This ferroresonant approach was widely used prior to having proper power elctronics at hand. Efficiency is pretty low at
Dear Salah,
To stretch your question a little further into 3-phase induction motor operation, which is practically a transformer in motion (slip dependent function), from an equivalent circuit point of view, passing a dc current through one phase will lead physically to braking or bringing the motor to a halt ... dynamic braking. For the transformer as a stationary machine, saturation of the core has been well described by our earlier colleagues comments.
The main problem it will introduce nonlinear load to the network and hence harmonics and resonance cases.