Understanding CT and VT Saturation Effects

[metsfan1395]

Can anyone explain why a CT would be subject to flux saturation, but a VT normally wouldn't?

 

[dlgoff]

Core saturation-of protective current transformers due to the d.c. component of fault current...

http://findarticles.com/p/articles/mi_qa3792/is_/ai_n8918425"

I would think that VTs would not see this d.c.component in its secondary during a line fault.

Welcome to PF

 

[m.s.j]

http://findarticles.com/p/articles/mi_qa3792/is_/ai_n8918425"

I would think that VTs would not see this d.c.component in its secondary during a line fault.

Excuse me, I think internet searching or data gathering without referring to basic concepts cannot solve our problems. Of course this is the disadvantage of today information explosion.

Magnetizing working point of voltage transformers is fixed by applied constant primary voltage. This working point doesn't vary even in secondary short circuit fault condition.
However in current transformers, the magnetizing working point varies when the primary/secondary current changes; because the link voltage of this type transformer is variable and may change proportion to multiplying of CT secondary current and secondary impedance. Therefore the voltage level of CT may be increased very much (CT saturation) due to primary short circuit fault currents.

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[dlgoff]

Excuse me, I think internet searching or data gathering without referring to basic concepts cannot solve our problems. Of course this is the disadvantage of today information explosion.

You're right. It wasn't a very good link.