Re: Saturable reactors?


The construction of a 'home brew' saturable reactor is quite a bit more
complicated that it first appears.  I looked into the potential of an SR to
control my pig, about a year ago.  Most SRs are wound on an E-I core with
the controlling winding on the center leg.  The outer two legs contain the
reactance windings.  They must be wound in opposite directions to cancel
their MMF to eliminate inducing AC in the control winding.  The control
winding is usually several HUNDRED turns of 24 or so AWG wire, and is
powered by a few hunderd volts.  I contacted several transformer/reactor
manufacturers and they said that they are very difficult to design properly.
Sure, you could home brew one, and it may work ok, but look for alot of
nonlinearities etc.   A pig itself can be used as an SR.  To me, this is a
better possibility than building one from scratch.  The way you do this is
to open the tank and connect the secondary windings in antiparallel (X1 to
X4 and X2 to X3) and place them in series with the load.  Connect the DC
controlling current to the HV bushings.  Make sure you have the proper
connections on the secondary, or the HV will appear on the primary!!  This
is not good.  Good luck, and be careful!