JPH07177648A - Dc interrupting system for superconducting unit - Google Patents

Dc interrupting system for superconducting unit

Info

Publication number
JPH07177648A
JPH07177648A JP32196093A JP32196093A JPH07177648A JP H07177648 A JPH07177648 A JP H07177648A JP 32196093 A JP32196093 A JP 32196093A JP 32196093 A JP32196093 A JP 32196093A JP H07177648 A JPH07177648 A JP H07177648A
Authority
JP
Japan
Prior art keywords
current
commutation
main circuit
superconducting
capacitor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP32196093A
Other languages
Japanese (ja)
Inventor
Kazuto Shimada
一人 島田
Original Assignee
Toshiba Corp
株式会社東芝
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, 株式会社東芝 filed Critical Toshiba Corp
Priority to JP32196093A priority Critical patent/JPH07177648A/en
Publication of JPH07177648A publication Critical patent/JPH07177648A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02Details
    • H01H33/59Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the ac cycle
    • H01H33/596Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the ac cycle for interrupting dc
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/001Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for superconducting apparatus, e.g. coils, lines, machines
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/60Superconducting electric elements or equipment or power systems integrating superconducting elements or equipment
    • Y02E40/68Protective or switching arrangements for superconducting elements or equipment

Abstract

PURPOSE:To interrupt a superconducting unit, where the current of main circuit varies with time, positively by detecting the current flowing through the main circuit and controlling the charging voltage of a commutation capacitor depending on the current thus detected. CONSTITUTION:A power supply 10 for charging a capacitor is provided with a circuit 12 for controlling the charging voltage of a commutation capacitor 7 based on the output from a detector 11 for detecting the current flowing through the main circuit. Charging voltage of the commutation capacitor 7 is controlled depending on the current flowing through the main circuit in order to optimize the commutation current at the time of interruption of the charging power supply 10. This constitution allows superposition of an optimal commutation current depending on the current flowing through the main circuit thus interrupting the main circuit positively at the time of abnormality and protecting a superconducting coil 1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a direct current interruption system for protecting a superconducting coil.

[0002]

2. Description of the Related Art In recent years, the progress of superconducting technology has been remarkable, and accordingly, the capacity of superconducting coils is gradually increasing. FIG. 3 shows an example of the configuration of the superconducting application device. The superconducting coil 1 is connected to an exciting power source 3 via a DC breaker 2. When an abnormality occurs in this system, it is common to close the switch 4 connected in parallel with the superconducting coil 1 and open the DC breaker 2 to divert a current to the damping resistor 5 to protect the superconducting coil. Target. Here, there is no problem when the energizing current of the superconducting coil is less than or equal to the rated breaking current of the breaker, but when the current becomes large, the DC breaker 2 needs to be configured by connecting a plurality of breakers in parallel. In the case of parallel operation like this,
Vacuum breakers are often applied because of the arc voltage-current characteristics.

FIG. 4 shows an example of the configuration of a direct current circuit breaker system in which a vacuum circuit breaker is connected in parallel to form a direct current circuit breaker. A forced commutation circuit including a commutation reactor 6, a commutation capacitor 7, and a closing switch 8 is connected in parallel with the DC breaker. The forced commutation circuit superimposes an oscillating current in the opposite direction to extinguish the arc generated when the direct current is cut off, and forcibly forms a current zero point. The capacitor charging power source 9 is for accumulating a predetermined charge in the commutation capacitor 7.

[0004]

By the way, in such a DC interruption system, the constant current of the commutation circuit is determined based on the maximum interruption current of the main circuit and is invariable. There is a problem that the interruption becomes uncertain in a superconducting application device that changes dynamically. When the circuit is interrupted while the maximum current is flowing in the main circuit, the current change rate (di / dt value) of the current flowing through the circuit breaker near the current zero point is determined by the characteristic of the circuit breaker.
Since the constants are determined so as to be equal to or less than the dt value, the main circuit current can be cut off without fail. However, when the energizing current is small under the condition that the commutation capacitor constant is the same, the di / dt value near the current zero becomes severe.
If the i / dt value exceeds the di / dt value allowed by the circuit breaker, the case of failure of the circuit occurs, which adversely affects the protection of the coil. SUMMARY OF THE INVENTION An object of the present invention is to provide a DC cutoff system for a superconducting application device in which the cutoff is reliable.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a direct current interruption system for a superconducting application device according to the present invention detects an energizing current of a main circuit and charges a commutation capacitor in accordance with the energizing current. The configuration has a function of controlling the voltage.

[0006]

According to the present invention, the optimum commutation current can be superimposed by controlling the charging voltage of the commutation capacitor in accordance with the current flowing through the main circuit, and the cutoff can be surely performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a DC cutoff system for a superconducting application device according to the present invention will be described below with reference to FIGS. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. The difference between FIG. 1 and FIG. 3 is that the commutation capacitor 7 is provided inside the capacitor charging power source 10 on the basis of the output from the detector 11 for detecting the energizing current of the main circuit.
That is, the control circuit 12 for controlling the charging voltage of is provided.
FIG. 2 is a diagram showing the relationship between the conduction current of the main circuit, the commutation current, and the breaking current when the commutation current is superimposed. When the charging voltage is not controlled as in the conventional case, the commutation current is determined based on the maximum energizing current and is unchanged. When the current flowing through the main circuit changes and is small at the time of interruption, di / dt near the point where the current flowing through the interrupter crosses the zero point
The higher the value, the more uncertain the interruption. But,
If the energizing current of the main circuit is detected and the charging voltage of the commutation capacitor is controlled according to the value, di / d near the current zero point
The t value can be suppressed to the di / dt value allowed by the circuit breaker.

The commutation capacitor charging power supply 10 controls the charging voltage of the commutation capacitor in accordance with the energizing current of the main circuit in order to make the commutation current at the time of interruption an optimum value. For example, by configuring the charging power source with a forward conversion device and a reverse conversion device, the reverse conversion device discharges the commutation capacitor when the energizing current of the main circuit decreases, and when it increases, the forward conversion device charges the commutation capacitor to convert the current. It is possible to control the charging voltage of the flow capacitor to an optimum value.

It should be noted that the same effect can be expected if the charging power source is composed of a forward converter and a discharge resistor and the capacitor charging voltage is controlled. Further, the same effect can be expected by varying the capacity of the commutation condenser or the capacity of the commutation reactor to control them.

[0010]

According to the present invention, since the commutation capacitor charging voltage can be controlled according to the energizing current of the main circuit, it is possible to superimpose an optimum commutating current according to the energizing current of the main circuit. When abnormal, the main circuit can be cut off surely and the coil can be protected.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a superconducting application device showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a main circuit energization current, a commutation current, and an energization current of a circuit breaker.

FIG. 3 is a configuration diagram showing an embodiment of a conventional superconducting application device.

FIG. 4 is a configuration diagram showing an embodiment of a conventional DC breaker.

[Explanation of symbols]

1 ... Superconducting coil, 2 ... DC breaker, 3 ... Excitation power supply,
4 ... switch, 5 ... damping resistance, 6 ... commutation reactor, 7
... commutation capacitor, 8 ... closing switch, 9 ... capacitor charging power supply, 10 ... capacitor charging power supply, 11 ... detector, 12 ...
Control circuit.

Claims (5)

[Claims]
1. A superconducting coil, an exciting power source for exciting the superconducting coil, a breaker interposed between the superconducting coil and the exciting power source to cut off a main circuit current, and in parallel with the breaker. A forced commutation circuit that is connected and that has a commutation capacitor that superimposes a reverse current between the contacts of the circuit breaker when cutting off the main circuit current; a charging power supply that accumulates charges in the commutation capacitor; A DC cutoff system for a superconducting application device, comprising: a control circuit for controlling a charging voltage of a capacitor according to a main circuit current.
2. The DC cutoff system for a superconducting application apparatus according to claim 1, wherein the control circuit for controlling the charging voltage of the commutation capacitor comprises a forward converter and an inverse converter.
3. The DC cutoff system for a superconducting application device according to claim 1, wherein the control circuit for controlling the charging voltage of the commutation capacitor comprises a forward converter and a discharge resistor.
4. The DC cutoff system for a superconducting application device according to claim 1, wherein the control circuit controls the capacity of the commutation capacitor according to the main circuit current.
5. The DC cutoff system for a superconducting application apparatus according to claim 1, wherein the control circuit controls the commutation reactor capacity according to the main circuit current.
JP32196093A 1993-12-21 1993-12-21 Dc interrupting system for superconducting unit Pending JPH07177648A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP32196093A JPH07177648A (en) 1993-12-21 1993-12-21 Dc interrupting system for superconducting unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP32196093A JPH07177648A (en) 1993-12-21 1993-12-21 Dc interrupting system for superconducting unit

Publications (1)

Publication Number Publication Date
JPH07177648A true JPH07177648A (en) 1995-07-14

Family

ID=18138353

Family Applications (1)

Application Number Title Priority Date Filing Date
JP32196093A Pending JPH07177648A (en) 1993-12-21 1993-12-21 Dc interrupting system for superconducting unit

Country Status (1)

Country Link
JP (1) JPH07177648A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011205887A (en) * 2010-03-25 2011-10-13 Abb Schweiz Ag Bridging unit
CN105244219A (en) * 2014-07-02 2016-01-13 株式会社日立制作所 Commutation type direct current breaker and monitoring method of the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011205887A (en) * 2010-03-25 2011-10-13 Abb Schweiz Ag Bridging unit
CN105244219A (en) * 2014-07-02 2016-01-13 株式会社日立制作所 Commutation type direct current breaker and monitoring method of the same
CN105244219B (en) * 2014-07-02 2017-09-19 株式会社日立产机系统 Commutation type DC breaker and its monitoring method

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