Saturable reactor

[buddy91082]

Hey there.

has anyone used a saturable recator in AC power systems to isolated grounds between primary and secondary windings of a transformers to isoalte from primary "noise" and high frequencies? I hear that a low currents it blocks "noise" but when saturated inductance drops allowing current to flow to trip teh circuit breakers.

 

[7anoter4]

A Saturable Reactor [or transformer] was used mainly in a Magnetic Amplifier provided with SCR. Now there is a proposal
how to used it in order to mitigate distortions on a power supply network.
See:
Suppression of Voltage Flicker by Saturable Reactor Operating under Forced Magnetization
by Bolgov, V.; Jarvik, J.;Estonia Univ. of Technol., Tallinn

http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4400513

 

[BrianG]

Buddy,
Saturable reactors / magnetic amplifiers are used in all sorts of applications, including switch-mode d.c. power supplies as a synchronous high efficiency series-pass regulator element (google 'flux re-setting saturable reactor'), however it sounds like a risky strategy for a circuit breaker.

All inductors (except air-cored) can be saturated at some current level, but to get a high inductance for the desired isolation at high frequencies ("noise") probably means either a good few turns of wire and/or very high permeability core material. Then when the fault current occurs, to trip the breaker this has to be able to saturate the core to flow through just the d.c. resistance of the winding with minimal voltage loss. Overall I think it would be difficult control the transition point consistently.