Quench detection method and apparatus of superconductive conductor
View Patent ↗When supplying electric power to a superconducting cable including a superconducting shield covering a superconductive conductor, a phase A of a current generated by a magnetic field leaking from the superconducting shield and a phase B of a current passing through the superconductive conductor are detected, and a phase difference between the phase A and the phase B is obtained so as to determine that a quench has occurred in the case where a difference between a reference phase difference and the obtained current phase difference exceeds a threshold.
1. A quench detection method of a superconductive conductor, on supplying electric power to a superconducting cable including a superconducting shield covering the superconductive conductor, the method comprising steps of: detecting a phase A of a current generated by a magnetic field leaking from the superconducting shield and a phase B of a current passing through the superconductive conductor; and obtaining a phase difference between the phase A and the phase B; and determining that a quench has occurred to the superconductive conductor when a difference between a reference phase difference and the obtained current phase difference exceeds a threshold.
2. The quench detection method of a superconductive conductor according to claim 1 , wherein the reference phase difference is the phase difference between the phase A and the phase B while supplying electric power in a state in which apparently no quench has occurred or in a state in which presumably no quench has occurred to the superconductive conductor.
3. The quench detection method of a superconductive conductor according to claim 2 , wherein the threshold is 0.2 degrees.
4. The quench detection method of a superconductive conductor according to claim 1 , wherein the reference phase difference is the phase difference between the phase A and the phase B obtained a certain time earlier than current time.
5. The quench detection method of a superconductive conductor according to claim 1 , wherein the threshold is 0.2 degrees.
6. The quench detection method of a superconductive conductor according to claim 4 , wherein the threshold is 0.2 degrees.
7. A quench detection apparatus of a superconductive conductor, comprising:
a first phase detector for detecting a phase A of a current generated by a magnetic field leaking from a superconducting shield of a superconducting cable including the superconducting shield covering the superconductive conductor;
a second phase detector for detecting a phase B of a current passing through the superconductive conductor;
a phase difference detector for obtaining a phase difference between the phase A and the phase B; and
a determiner for determining that a quench has occurred to the superconductive conductor when a difference between a reference phase difference and the obtained current phase difference exceeds a threshold.
8. The quench detection apparatus of a superconductive conductor according to claim 7 , wherein the reference phase difference is the phase difference between the phase A and the phase B while supplying electric power in a state in which apparently no quench has occurred or in a state in which presumably no quench has occurred to the superconductive conductor.
9. The quench detection apparatus of a superconductive conductor according to claim 8 , wherein the threshold is 0.2 degrees.
10. The quench detection apparatus of a superconductive conductor according to claim 7 , wherein the reference phase difference is the phase difference between the phase A and the phase B obtained a certain time earlier than current time.
11. The quench detection apparatus of a superconductive conductor according to claim 10 , wherein the threshold is 0.2 degrees.
12. The quench detection apparatus of a superconductive conductor according to claim 7 , wherein the threshold is 0.2 degrees.