JPH09260130A - Protection of superconductive current-carrying wire and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent burning of a superconductive coil current-carrying wire in the case of generated coil quenching at the time of current carrying through a superconductive coil from the outside for exciting and demagnetizing of the superconductive coil by detecting the coil quenching so as to cut a power supply current with an exciting power supply device set-up on the ground. SOLUTION: In a method of protecting a superconductive coil current-carrying wire 25 in the case of generated coil quenching at the time of current-carrying through the superconductive coils C1 to C4 from outside for exciting and demahnetizing the superconductive coils C1 to C4 being provided with and excited power supply device 11 to be arranged on the ground a superconductive magnet control device 21 to be mounted on a vehicle, when the coil quenching is detected basing on an abnormal voltage in an abnormal voltage detection tap T provided on the superconductive coils C1 to C4, a persistent current switch PCS to be in parallel connected to the superconductive coils C1 to C4 is put 'ON' so as to perform overvoltage detection through the superconductive coil current-carrying wire 25 and when this overvoltage exceeds a prescribed voltage, a breaker 13 is operated so as to cut off a power supply current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for protecting a superconducting coil current wire, and more particularly to a method and an apparatus for protecting a superconducting coil current wire used in a superconducting magnet of a superconducting magnetic levitation railway. .

[0002]

2. Description of the Related Art First, a conventional method of protecting a superconducting coil current line from quenching of a superconducting magnet during demagnetization in a superconducting magnetic levitation railway will be described. FIG. 2 is a block diagram of an excitation / demagnetization system of a superconducting magnet in such a conventional superconducting magnetic levitation railway.

In the conventional excitation / demagnetization of a superconducting magnet of a superconducting magnetic levitation type railway, as shown in FIG. 2, an abnormal voltage detecting wiring 5 for detecting an abnormal voltage generated at the time of quenching of the superconducting coils C1 to C4 is provided. , Pull up to the excitation power supply / control device 1 installed on the ground, judge the quench from the generated voltage, and forcibly cut off the power supply current from the excitation power supply / control device 1 that is supplying power at the time of demagnetization. It was a method of protecting 7. In addition, 2 is a quench detector, 3 is a PCS heater power source, 4 is a superconducting magnet, 6 is a control line of a permanent current switch for controlling the opening and closing of the permanent current switch PCS connected in parallel to the superconducting coils C1 to C4. .

In such a superconducting coil energizing wire protection system, an abnormal voltage detecting wiring 5 for detecting an abnormal voltage generated during quenching of the superconducting coils C1 to C4 is installed on the ground from all the superconducting coils C1 to C4. Excitation power supply
It is necessary to connect to the control device 1. In addition, in such a conventional protection system, for a moving object such as a superconducting magnetic levitation type railway vehicle, it is necessary to connect wiring from the ground during demagnetization and remove it when moving.

[0005]

In the future superconducting magnetic levitation railway, since the number of wiring lines for quench detection at the time of excitation and demagnetization as described above is large, it is not necessary to pull it into a device on the ground side. However, the wiring for detecting abnormal voltage of the superconducting coil is drawn into the superconducting magnet control device installed in the vehicle.

In this case, if a quench occurs in the superconducting coil when the superconducting magnet is energized and deenergized, the superconducting magnet controller installed in the vehicle can detect the quench, but the power supply current is supplied. On the side of the exciting power supply, the abnormality of the superconducting coil is not recognized and the power supply continues. As a result, the superconducting coil energizing wire may be blown.

Hereinafter, the process until the melting and cutting will be described. An example of the superconducting coil of the superconducting magnetic levitation railway has a wiring diagram as shown in FIG. As the superconducting coil conducting wires PL1 and PL2 shown in FIG. 3, thin wires are used to minimize heat intrusion from the outside, and superconducting wires are used so as to withstand a large current.

When the superconducting magnet having the above-mentioned current-carrying wire is excited and demagnetized, when the superconducting coil is in the permanent current mode and a coil quench occurs while the power is being supplied, the following mechanism is used. The superconducting coil energizing wire is blown. In the connection diagram, when the superconducting coil is quenched in the permanent current mode when energized in the excitation / demagnetization pattern as shown in FIGS. 4 and 5, the superconducting coil becomes normal conducting and generates heat as well as resistance. At this time, the current supplied from PL1 continues to flow to PL2 via the permanent current switch PCS because the permanent current switch PCS is closed.

At this time, since S-S 'and E-E' in FIG. 3 are in a state of being molded in the superconducting coil, S-S 'and E are generated by heat generated by quenching of the superconducting coil.
The superconducting wire between −E ′ also becomes normal conducting and resistance is generated, and if the power supply current continues to flow in that state, it will melt. Even if the current-carrying wire is not molded in the superconducting coil, the temperature around the current-carrying wire rises due to the heat generated by the coil quenching, and the resistance is generated in the current-carrying wire in the same manner as above, causing the power supply current to continue to melt and melt down. It will be.

That is, in FIG. 4, the left side of the dotted line shows the state in which the permanent current switch PCS is open, and the right side of the dotted line shows that the superconducting coil is in the persistent current mode. Further, when the coil quench occurs when the power supply current is particularly large in the section of T ₀₁ , the current-carrying wire is melted. Further, in FIG. 5, the left side of the dotted line indicates that the superconducting coil is in the permanent current mode, and the right side of the dotted line indicates that the permanent current switch PCS is in the open state. In addition, if a coil quench occurs when the power supply current is particularly large in the section of T ₀₂ , the current-carrying wire is blown.

The present invention eliminates the above-mentioned problems and, in order to demagnetize the superconducting coil, when a coil quench occurs while a current is being supplied to the superconducting coil from the outside, the coil quench is detected, and the ground quench is detected. It is an object of the present invention to provide a method of protecting a superconducting coil energizing wire and a device thereof, which can prevent the burning of the superconducting coil energizing wire by shutting off the power supply current with the exciting power supply device installed in.

[0012]

In order to achieve the above object, the present invention comprises (1) an excitation power source arranged on the ground and a superconducting magnet control device mounted on a vehicle, which excites a superconducting coil. In a method of protecting a superconducting coil current line when a coil quench occurs when a current is being supplied to the superconducting coil from the outside for degaussing, a coil quench is performed based on an abnormal voltage in an abnormal voltage detection tap provided in the superconducting coil. When it is detected, the permanent current switch PCS connected in parallel with the superconducting coil is opened, and the overvoltage is detected through the superconducting coil energizing wire. When the overvoltage exceeds a predetermined voltage, the breaker is operated to change the power supply current. It is designed to be cut off.

(2) An exciting power source arranged on the ground and a superconducting magnet control device mounted on a vehicle are provided, and in order to demagnetize the superconducting coil, a coil quench is generated when a current is externally applied to the superconducting coil. In the protection device for the superconducting coil energizing wire when it occurs, an abnormal voltage detection tap provided on the superconducting coil, and a permanent current switch PCS connected in parallel with the superconducting coil based on the abnormal voltage at the abnormal voltage detection tap. Opening control means, overvoltage detection means for detecting an overvoltage via the superconducting coil energization wire, comparison means for comparing the output voltage of the overvoltage detection means with a predetermined voltage, and the comparison means for setting the output voltage to a predetermined value. A circuit breaker for shutting off the power supply current when the voltage exceeds the voltage is provided.

With the above-described structure, when a coil quench occurs while a current is being supplied to the superconducting coil from the outside in order to demagnetize the superconducting coil of the superconducting magnet, the coil quench is detected and grounded. The power supply current can be interrupted by the excitation power supply device installed in the superconducting coil, and burnout of the superconducting coil energizing wire can be accurately prevented.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below by taking a case of a superconducting magnet of a superconducting magnetic levitation railway as an example. FIG. 1 is a configuration diagram of a protection system for a superconducting coil current-carrying wire showing an embodiment of the present invention. Here, for simplification of description, the diode and the protection resistor (see FIG. 6) connected to the persistent current switch PCS are omitted.

In the figure, reference numeral 21 is a superconducting magnet control device mounted in the vehicle, 22 is a pair of superconducting magnets mounted on both sides of the vehicle, and is composed of superconducting coils C1 to C4 and respective superconducting coils C1 to C4. It has a corresponding persistent current switch PCS connected in parallel. An abnormal voltage detection tap T is provided on each of the superconducting coils C1 to C4. When a quench occurs in the superconducting coils C1 to C4, the abnormal voltage due to the quench is detected to detect the abnormal voltage detection wiring 23. Through the superconducting magnet control device 21 via the superconducting coils C1 to C4
And the quench of the superconducting coils C1 to C4 can be detected.

The permanent current switch PCS includes a heater H and an opening / closing section, and the permanent current switch control line 2
The heater H is turned on and off by the superconducting magnet control device 21 via the switch 4, and the permanent current switch P
The opening / closing part of the CS can be controlled. On the other hand, the excitation power supply device 11 arranged on the ground has the superconducting coil conducting wire 25.
The superconducting coils C1 to C4 are energized via. The excitation power supply device 11 includes an overvoltage detection device 15, which will be described later, a detection voltage of the overvoltage detection device 15 and a predetermined voltage (reference voltage).
Comparing section 14 for comparing with, circuit breaker 13, excitation power supply 1
2 is provided.

Therefore, when the superconducting coils C1 to C4 are in the permanent current mode and a coil quench occurs while the power supply current is being supplied, the superconducting magnet controller 21 mounted on the vehicle quenches the superconducting coils. Detect C1-C4 and its quench. At the same time, the superconducting magnet controller 21 energizes and heats the heater H of the permanent current switch PCS of the quenched superconducting coil.

Then, resistance is generated in the permanent current switch PCS. The voltage generated by the resistance of the parallel circuit of the resistance of the permanent current switch PCS and the resistance generated by the coil quench and the power supply current operates the overvoltage detection device 15 of the excitation power supply device 11, and is detected by the comparison unit 14. The overvoltage is compared with a predetermined voltage stored in advance, and when the overvoltage exceeds the predetermined voltage, the circuit breaker 13 is operated to cut off the energized power supply current.

Specific examples of the present invention will be described below.
The overvoltage detection device 15 and the comparison unit 14 shown in FIG. 1 are a meter in which a power supply current output voltage meter and an output overvoltage operation relay are incorporated between the superconducting coil conducting wires 25 connected to the excitation power supply device 30 (see FIG. 6). It is composed of a relay 31. The circuit breaker 32 is a DC circuit breaker (DCC
B) is used. Incidentally, 33 is an exciting power source.

The set value of this output overvoltage operation relay is currently set to ± 300V. Therefore, the output voltage is ± 300 V when connected to the superconducting magnet 22 which is a load and energized.
When the voltage exceeds, the output overvoltage operation relay operates (contact opens), the relay relay is demagnetized, the relay operation contact closes, the DC circuit breaker (DCCB) is cut off, and the energization is cut off.

FIG. 6 is an electric circuit diagram of a superconducting magnet showing a specific example of the present invention. In this figure, L1 to L8 are superconducting coils, for example, 2.7H, P1 to P8 are permanent current switches PCS, and R1 to R8 are protective resistors (0.1).
Ω) and D1 to D8 are diodes. FIG. 7 is a diagram showing an output voltage when the superconducting magnet is normally excited.

As shown in FIG. 7, time t when the power supply current is 0
The output voltage is about 110V from ₁₁ to time t ₁₂ when it reaches about 500A. That is, in the superconducting magnet shown in FIG.
During excitation, most of the power supply current flows to the superconducting coil side, and the output voltage V is V = L ₁ (di / dt) + L ₂ (di / dt) + ... + L ₈ (di / dt) = 8L (di /Dt)=8×2.7(H)×5(A/sec)=108(V).

FIG. 8 shows the output when the superconducting magnet is demagnetized under normal conditions.
It is a figure which shows a voltage. As shown in this figure,
Time t 0_{twenty one}From time t to about 500A _{twenty three}Up to
The output voltage is 0 because the permanent current switch PCS is closed.
Yes, at this time t_{twenty three}Permanent current switch PCS opens with
The power supply current is gradually reduced at time t_{twenty four}Power on
The current becomes zero. In that case, time t_{twenty three}Gradually from-direction
Output voltage V (voltage due to back electromotive force) is generated at
The pressure becomes -V about 100V. When degaussing, the permanent current
Protection resistors R1 to R8 connected in parallel to the switch PCS
Current will also flow to.

Next, the output voltage at the time of abnormality of the present invention will be described. (1) During excitation / demagnetization, if a coil quench occurs when the permanent current switch PCS is open, the resistance (several Ω) generated by the coil quench × the voltage generated by the power supply current is
Excitation power supply reference voltage (overvoltage detection set value) (± 300
V) or more. (2) When a coil quench occurs when the permanent current switch PCS is closed during excitation / demagnetization, according to the present invention,
When the permanent current switch PCS is opened simultaneously with the detection of the quench, the voltage generated by the resistance (several Ω) generated by the coil quench × the power supply current becomes equal to or higher than the reference voltage (overvoltage detection set value) (± 300 V) of the excitation power supply.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0027]

As described above in detail, according to the present invention, when a coil quench occurs while a current is externally applied to the superconducting coil in order to demagnetize the superconducting coil of the superconducting magnet, The coil quench is detected, and the power supply current is cut off by the excitation power supply device installed on the ground, so that the burnout of the superconducting coil energizing wire can be accurately prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a superconducting coil current-carrying wire protection system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an excitation / demagnetization system of a superconducting magnet in a conventional superconducting magnetic levitation railway.

FIG. 3 is an explanatory view of melting of a superconducting coil current-carrying wire.

FIG. 4 is an explanatory view (No. 1) of energization state of the superconducting coil and fusing.

FIG. 5 is an explanatory view (No. 2) of energization state of the superconducting coil and fusing.

FIG. 6 is an electric circuit diagram of a superconducting magnet showing a specific example of the present invention.

FIG. 7 is a diagram showing an output voltage when a superconducting magnet is normally excited.

FIG. 8 is a diagram showing an output voltage when the superconducting magnet is normally demagnetized.

[Explanation of symbols]

 11,30 Excitation power supply device 12,33 Excitation power supply 13,32 Circuit breaker 14 Comparison unit 15 Overvoltage detection device 21 Superconducting magnet control device (mounted in vehicle) 22 Superconducting magnet 23 Abnormal voltage detection wiring 24 Permanent current switch control line 25 Superconducting coil energizing wire 31 Meter relay C1 to C4 Superconducting coil PCS Persistent current switch (P1 to P8) T Abnormal voltage detection tap H Heater R1 to R8 Protection resistance D1 to D8 Diode

Claims (2)

[Claims] 1. A coil quench is generated when an electric current is supplied to the superconducting coil from the outside in order to demagnetize the superconducting coil, which comprises an exciting power source arranged on the ground and a superconducting magnet control device mounted on the vehicle. In the method of protecting the superconducting coil conducting wire in the case of, when detecting the coil quench based on the abnormal voltage in the abnormal voltage detection taps provided in the superconducting coil,
The permanent current switch connected in parallel with the superconducting coil is opened, overvoltage detection is performed through the superconducting coil energizing wire, and when the overvoltage exceeds a predetermined voltage, the circuit breaker is operated to interrupt the power supply current. A method of protecting the superconducting coil current conductor. 2. A coil quench is generated when an electric current is supplied to the superconducting coil from the outside in order to demagnetize the superconducting coil, which comprises an exciting power source arranged on the ground and a superconducting magnet control device mounted on the vehicle. In the protection device for the superconducting coil energization wire in such a case, (a) an abnormal voltage detection tap provided on the superconducting coil, and (b) a permanent connection connected in parallel with the superconducting coil based on the abnormal voltage at the abnormal voltage detection tap. Control means for opening the current switch, (c) overvoltage detection means for detecting an overvoltage via the superconducting coil energizing wire, (d) comparison means for comparing the output voltage of the overvoltage detection means with a predetermined voltage, (E) A protection device for a superconducting coil energizing wire, comprising a circuit breaker for interrupting a power supply current when the output voltage exceeds a predetermined voltage by the comparing means.