Talk-Polywell.org

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http://www.iop.org/EJ/article/-alert=34 ... 3ded361c37

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High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations—HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.

Interesting stuff about high power XFMR winding.

Surely it's a 'superconductor' to DC current, not AC current? With an AC induction current, it'll heat up by magnetic induction (rather than electron conduction, which it won't suffer from anyway) so even if it could survive and not get quenched then it'd hardly be that much better?

Better to use stocks of silver bullion to make transformer wire, like the calutrons used!

Magnetic induction causes heat by inducing eddy currents in a conductor (specifically, the iron core, iron not being a brilliant electrical conductor (fantastic magnetic)) and the currents causing resistive heating. This is why the iron cores of any magnetic device (transformers, motors, etc) are layered: to keep the sizes of the eddies, and thus the amount of heating, to a minimum.

Eddy currents in a superconductor won't create much heat (though they might quench the SC).

SC transformers won't do anything to reduce the magnetic heating of the core, but they will reduce the resistive heating of the coils. This will reduce the difficulty of keeping the core cool as the only source of heating has become the magnetically induced eddy currents as there will no longer be any heat conducted from the coils.

In fact, since even HSC still require cooling (liquid nitrogen, AIUI), this will have the side "benefit"* of cooling the core as well.

*not so good for the cooling of the coils.

I speculate that the size and isolation of a pole transformer would make cooling it very difficult unless the superconductor workes well above room temperature (rolled graphine may be an alternative). If efficient thermocuple coolers could keep the transformer cool enough at a low enough electrical cost, I suppose it might worthwhile.
How big of a quench explosion would you get if someone shot the transformer?

A supeconducting substation might be a more pratical target for superconducters. How much power is lost at substations compared to all of the pole PIGS that are fed from the substation?

Dan Tibbets

D Tibbets wrote:I speculate that the size and isolation of a pole transformer would make cooling it very difficult unless the superconductor workes well above room temperature (rolled graphine may be an alternative). If efficient thermocuple coolers could keep the transformer cool enough at a low enough electrical cost, I suppose it might worthwhile.
How big of a quench explosion would you get if someone shot the transformer?

A supeconducting substation might be a more pratical target for superconducters. How much power is lost at substations compared to all of the pole PIGS that are fed from the substation?

Dan Tibbets

Most of our AC low power (under 100 KW or so) will not change. Heat loss/gain goes down linearly with a linear decrease in dimensions. Substations and up will benefit.