Sumitomo Electric Industries, Limited

Shigeki Isojima

Shuichi Nogawa

Kazuhiro Kuroda

Kouji Noguchi

Toru Okazaki

Katsuya Hasegawa

Shuuichi Nogawa

A current-limiting device is a current-limiting device that uses a superconductor to perform a current-limiting operation, the current-limiting device including: a superconducting current-limiting element including the superconductor; a capacitor; a reactor; and a bypass switch. The series capacitor is connected in series to the superconducting current-limiting element. The current-limiting reactor is further connected in series to a series circuit including the superconducting current-limiting element and the series capacitor. The thyristor switch is connected in parallel to the series circuit.

Current-limiting device utilizing a superconductor for a current-limiting operation

A current-limiting and power-flow control device according to the present invention includes a superconducting current-limiting element including a superconductor, a series capacitor, and a parallel circuit. The series capacitor is connected in series with the superconducting current-limiting element. The parallel circuit includes a reactor connected in parallel with a series circuit including the superconducting current-limiting element and the series capacitor. Accordingly, overcurrent at the time of occurrence of a fault causes transition of the superconductor of the superconducting current-limiting element to the normal conducting state, and thus causes autonomous current-limiting operation of the superconducting current-limiting element. Thus, application of an excessive load across the terminals of the series capacitor due to the aforementioned fault can surely be prevented. Accordingly, unlike the conventional device, it is unnecessary to install an arrester for protection of the series capacitor and the configuration of the current-limiting and power-flow control device can be simplified.

Current-limiting and power-flow control device

Provided is a fault current limiter that uses a superconductor and can rapidly restore a superconducting state after a current limiting operation. The fault current limiter is configured to perform a current limiting operation through the use of a superconductor and includes a superconducting member (a member including a holding container, a filler and a superconducting wire) including the superconductor, a cooling container, and a suppression member (fins). The cooling container is configured to hold therein the superconducting member and house therein a coolant for cooling the superconducting member. The suppression member (fins) is configured to prevent a boiling state of the coolant from transiting from a nucleate boiling state to a film boiling state in the case where the coolant boils on a surface of the superconducting member (a surface of the holding container) due to a temperature rise of the superconductor during the current limiting operation.

Fault current limiter

A saddle type dipole coil comprises a pair of elongated ring shaped upper and lower coil layers each having an assembly of coil conductors of series-connected turns. The upper and lower coil layers are opposed each other and disposed on the outer surface of a duct. The end portions of the upper and lower coil layers positioned in a range of a predetermined width are so extended by a predetermined length in the longitudinal direction that the integral value of only sextupole components of a magnetic field is minimized or set nearly zero among the entire multi-pole components of the magnetic field, thereby enabling to make a synchrotron radiation ray generating device with good efficiency of accelerating particles.

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Osaka, Japan

Shigeki Isojima