Superconducting current limiting element
A superconducting current limiting element has a parallel circuit including a first superconductor and a normal conductor connected in parallel, and a second superconductor connected in series to the parallel circuit and having a critical current value higher than that of the first superconductor. Further, at least one of the normal conductor and the first superconductor, and the second superconductor are disposed on the same insulating substrate.
1. A superconducting current limiting element comprising:
an insulating substrate;
a parallel circuit including a first superconductor and a normal conductor connected in parallel, the first superconductor and the normal conductor being formed on a first surface of the insulating substrate; and
a second superconductor connected in series to the parallel circuit and having a critical current value higher than that of the first superconductor, the second superconductor being formed on a second surface of the insulating substrate.
2. The superconducting current limiting element according to claim 1 , wherein the first superconductor has a higher critical current density and causes transition to a normal-conducting state easier than the second superconductor.
3. The superconducting current limiting element according to claim 1 , wherein the normal conductor is formed of nickel, and the first and second superconductors are formed of a Y-based superconductor, respectively.
4. The superconducting current limiting element according to claim 1 , wherein the insulating substrate is formed of sapphire.
5. The superconducting current limiting element according to claim 4 , wherein the second superconductor is epitaxially deposited on CeO2 which is epitaxially deposited on the sapphire substrate.
6. The superconducting current limiting element according to claim 4 , wherein the first superconductor is epitaxially deposited on CeO2 which is epitaxially deposited on the sapphire substrate.
7. The superconducting current limiting element according to claim 1 , wherein heat generated both in the first superconductor and in the normal conductor is conducted to the second superconductor.