초록 ▼

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel conne

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

대표청구항 ▼

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] Fault current limiting apparatus for limiting excessive current in a circuit, said apparatus comprising:a first coil carrying a first current producing a first magnetic flux;a seco

[ The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:] [1.] Fault current limiting apparatus for limiting excessive current in a circuit, said apparatus comprising:a first coil carrying a first current producing a first magnetic flux;a second coil magnetically coupled to said first coil and carrying a second current producing a second magnetic flux, wherein said first and second magnetic fluxes are opposed and cancel each other to provide a low impedance under normal operating conditions; andfault detection means connected in series with said second coil and responsive to a large fault current in said second coil for producing a magnetic flux density imbalance and inductively increasing the impedance in said first and second coils for limiting the fault current in the circuit.