COMPLEX SUPERCONDUCTING FAULT CURRENT LIMITER
First Claim
1. A complex superconducting fault current limiter comprising:
- a superconductor which is connected in series to a power line;
a first switch which is connected in series to the superconductor, is closed to allow the current to flow on the power line when a normal current flows on the power line, and opened, when a large current flows on the power line, to break the power line, the first switch being opened by a magnetic force;
a first reactor which has a first impedance that is smaller than an impedance of the superconductor when a larger current flows on the power line, is connected in parallel to the superconductor, and serves as a branch path for the current flowing through the superconductor and the first switch when a larger current flows on the power line, the first reactor being magnetized by the current flowing through the branch path thus to switch the first switch to be opened;
a second reactor which is connected in series to the branch path formed by the first reactor, and has a second impedance that is larger than the first impedance of the first reactor so as to limit the large current;
a semiconductor switch which is connected in parallel to the second reactor and capable of turning on by a trigger signal; and
a trigger controller which stops sending a trigger signal to the semiconductor switch in response to the opening of the first switch.
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Accused Products
Abstract
The present invention relates to a complex superconducting fault current limiter which adds a current limiting reactor to a superconductor to protect the power line from a fault current, and more particularly, to a complex superconducting fault current limiter using a minimum number of superconducting fault current limiters, while avoiding series and parallel connections of a plurality of superconductors and coils, in order to economically manufacture the fault current limiter in a small size. A superconductor, a high speed switch, and a circuit breaker are connected in series to each other, and a first reactor with a low impedance and a second reactor with a high impedance are connected in parallel to the power line so as to provide a branch circuit for the current to the series circuit. A semiconductor switch is connected in parallel to the second reactor with a high impedance in accordance with the opening high speed switch. A circuit is breaker trip drive controller is configured so as to be connected to the superconductor and the branch circuit, and when a fault current occurs, the fault current is branched into the branch circuit, so that the second reactor limits the fault current. When a fault current occurs, the circuit breaker trip drive controller provides a trip drive signal to the circuit breaker for tripping in accordance with the voltage of the superconductor or the current of the branch circuit.
30 Citations
10 Claims
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1. A complex superconducting fault current limiter comprising:
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a superconductor which is connected in series to a power line; a first switch which is connected in series to the superconductor, is closed to allow the current to flow on the power line when a normal current flows on the power line, and opened, when a large current flows on the power line, to break the power line, the first switch being opened by a magnetic force; a first reactor which has a first impedance that is smaller than an impedance of the superconductor when a larger current flows on the power line, is connected in parallel to the superconductor, and serves as a branch path for the current flowing through the superconductor and the first switch when a larger current flows on the power line, the first reactor being magnetized by the current flowing through the branch path thus to switch the first switch to be opened; a second reactor which is connected in series to the branch path formed by the first reactor, and has a second impedance that is larger than the first impedance of the first reactor so as to limit the large current; a semiconductor switch which is connected in parallel to the second reactor and capable of turning on by a trigger signal; and a trigger controller which stops sending a trigger signal to the semiconductor switch in response to the opening of the first switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A complex superconducting fault current limiter comprising:
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a superconductor which is connected in series to the power line; a first switch which is connected in series to the superconductor, is closed to allow the current to flow on the power line when a normal current flows on the power line, and opened, when a large current flows on the power line, to break the power line, the first switch being opened by a magnetic force; a first reactor which has a first impedance that is smaller than an impedance of the superconductor when a larger current flows on the power line, is connected in parallel to the superconductor, and serves as a branch path for the current flowing through the superconductor and the first switch when a larger current flows on the power line, the first reactor being magnetized by the current flowing through the branch path thus to switch the first switch to be opened; a second reactor which is connected in series to the branch path formed by the first reactor, and has a second impedance that is larger than the first impedance of the first reactor so as to limit the large current; a semiconductor switch which is connected in parallel to the second reactor and capable of turning on by a trigger signal; a trigger controller which stops sending a trigger signal to the semiconductor switch in response to the opening of the first switch; a circuit breaker which breaks the power line when a large current flows on the power line, the circuit breaker being connected to the power line behind the superconductor, the first switch and the branch path; a current transformer which is connected to the branch path so as to detect the current flowing through the branch path, and outputs a first voltage signal corresponding to the detected current; and a circuit breaker trip drive controller which comprises a first input that is connected to the superconductor and to which a second voltage signal corresponding to the voltage of the superconductor is input, and a second input to which a first voltage signal from the current transformer is input, and provides a trip drive signal to the circuit breaker when either the first voltage signal or the second voltage signal is input.
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Specification