Superconductor Fault Current Limited (SFCL)

The critical factors of a superconductor are very different than a regular conductor. With a superconductor there is a critical temperature that all of the superconducting material must remain below for super-conduction to happen. The maximum current density will increase non-linearly as one is able to chill the superconductor below the critical temperature. Metallic superconductors have a critical temperature requiring liquid helium. The recently developed warm superconductors have a critical temperature just above liquid nitrogen. Unlike metallic superconductors these warm superconductors are poor conductors when not superconducting. This is one of the reasons these conductors are normally "sandwiched" between two copper foils. Quenching the superconductor by exceeding the current for the temperature will immediately cause the copper to conduct instead. This then creates self heating at the location and a potential quick runaway condition. This is why most superconductor work is done in a cryogenic bath. To make things more interesting there is a little understood very tiny amount of self heating that happens to a superconductor while in super-conduction.

Another aspect that people forget is that a superconductor only changes the resistance of a circuit path. The inductive coupling effects from the current path are still present. So a quick change in current can generate a voltage across the superconductor from this inductance. With the copper clad versions of this conductor current can now flow in the copper making for self heating and another possibility of a quench.

This is not simple work.

To directly answer your question, yes, I work with superconductors. There are many aspects I would need to know to be able to give sound advice. The first two things are will my employer allow me to work with you and will you pay me my fee?

Thanks, but I am well know about the theorical philosophy of the SFCL from academic papers, What I try to find is if any of the Forum member has experienced of this equipment and results in any industrial scheme or manufacturer suppliers.

Would you help please

Bye

So far you've not provided any information that I can help you with. I have fiduciary responsibilities with my employer, experimenters and vendors. You haven't explained anything that tells me why you wish for details on quenching a superconductor.

You've yet to even demonstrate a working knowledge of the hazards of working with a superconductor, let alone a current fault condition. For starters, can you identify some of the hazards of working with a superconductor?

From the beginning I only asked for the results of the possible application of the SFCL in your MV internal distribution system to limit the fault current instead reactor or high impedence transformer.

Yes, there are hazards condition from the superconductor related to the quenching process phenomenon during transition between the superconductor and normal conducting regime in terms of heating during quenching process which is incontrolled (is what hazard you referes to ?)

Other technologies alternative can be used like shielded-core saturable SFCL (now in service By Zenergy Power Inc.), Hybrid Resistence SFCL , Solid-state and Is-Limited (from ABB).

I insist please let me know based from your experiences or results of any above mentioned method

Bye everyone