| 摘要 |
PURPOSE:To obtain a simple and highly reliable DC current limiter by detecting an overcurrent by a first coil to automatically energize a second coil, and altering a superconducting state to a normal conducting state using this magnetic field. CONSTITUTION:The main circuit of a first coil 11 is held in a superconducting state in a steady state, the relation of a current i1= io is set. When an overcurrent flows due to a short-circuit accident, the current i1 increases, a voltage corresponding to the product of a current change and the reactance of the coil 11 is generated in the coil 11, and a current i2 flows, part of the current i2 becomes a current i4, thereby energizing a second coil 13. When a magnetic field generated from the coil 13 exceeds the critical magnetic field of the coil 11 of the superconducting member, the first coil 11 can not hold the superconducting state to generate a resistance, thereby limiting the current. In this case, the voltage of the coil 11 tends to abruptly rise, but a current flows to the parallel resistor 14 of the coil 13, thereby preventing an extreme overvoltage from generating. |
