Re: Three phase transformer arrived for saturation experimentation.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

There shouldn't be any AC in the center windings if
the outer windings are connected properly.  However it
*does* seem as though saturation ought to be more
easily achieved using the outer two HV windings for
the control rather than the inner HV winding.  The
legs of a three-phase transformer all have the same
cross-sectional area.  That suggests that saturating
the center leg will not translate into saturation of
the outer legs.  However, by applying a suitable
current to the outer HV windings (wired so as to aid
each other), it seems one ought to be able to
completely saturate the outer legs quite easily.  On
hvlist, however, it was mentioned that complete
saturation by the control alone is generally not
required when the power winding is passing current, so
considering saturation from the point of the control
may not be completely valid.  I'd love to see it tried
both ways, if possible.

40 ohms on the 5kV windings sounds like goodness to
me!

Regards,
Aaron, N7OE

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: Steve Conner <steve@xxxxxxxxxxxx>
>
> Hi Jim, all,
>
> A few thoughts on using a three phase transformer as
> a saturable reactor.
>
> I don't think you can use the centre limb as the
> control winding,
> because having only a single winding, you can't
> cancel the induced
> AC. I think the only hook-up that will do anything
> is to use the 208V
> winding on the centre leg in series with the load,
> and the HV
> windings on the two outer legs as the control
> windings.
>
> As for how much control current will be needed: I
> think amp-turns are
> conserved. So if you pass 1 amp through each of the
> 5kV HV windings
> in series, it would try to deliver about
> 1A*(5000*2/208)= 48A to the
> load, and since the rated HV output current is 1A,
> that would be a
> reasonable maximum rating for the thing as a
> saturable reactor.
>
> Steve Conner
> http://www.scopeboy.com/
>
>
>