JP2851189B2 - Short-circuit current suppression device and short-circuit current interruption device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for suppressing short-circuit current of various switches and an apparatus for interrupting short-circuit current.

[0002]

2. Description of the Related Art Recently, for example, in order to cope with an increase in short-circuit current due to an increase in capacity of a distribution system, a short-circuit current is suppressed.
An interrupting device is required.

[0003] Currently studied and proposed types of short-circuit current suppression devices forcibly interrupt the arc before the first wave of short-circuit current peaks. Examples of this type include a semiconductor commutation type in which a thyristor or a gate turn-off thyristor cuts off and commutates to a resistor, and an arc-driven type in which an arc is run between resistive parallel electrodes to limit the current. is there.

However, such a short-circuit current suppressing device requires a considerable amount of time to be put to practical use in terms of complexity, size, reliability, and economy.

Therefore, the present invention aims at suppressing the second and subsequent short-circuit currents. For this purpose, an attempt is made to provide a short-circuit current suppressing device that cuts off and commutates when the first zero point of the short-circuit current is reached. Is what you do.

That is, as shown in FIG. 7, when a detector detects a short-circuit current, the switch is opened, and after opening, a current of, for example, about 1000 A is loaded through a current limiter connected in parallel with the switch. Adopt a system to supply.

[0007]

By the way, according to the contact structure of the switch for interrupting a short-circuit current, a bridge type bridge between both fixed contacts or a movable contact has a fulcrum at a certain hinge point. There is a type called a rotary contact type, which rotates as a contact type, and a type called a butt contact type in which one of two rod-shaped contacts whose ends are contact points moves linearly with respect to the other. The former two have a problem that it is difficult to use them at high pressure because a gap between contacts cannot be made large in order to obtain an effective electromagnetic force. The latter is generally difficult to obtain using the electromagnetic force of a short-circuit current. However, in this butt contact type, if an effective electromagnetic force can be obtained in the direction of the butt contact, there is a possibility that it can be used at a high pressure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a short-circuit current suppressing device and a short-circuit current interrupting device having a trip mechanism that can be reduced in size.

[0009]

To solve this problem, the present invention provides a switch, a latch mechanism for holding a movable pole of the switch in a closed state, a fixed pole terminal of the switch and a movable pole. A short-circuit current suppression device comprising: an impedance connected between the movable electrode and a trip mechanism that opens the movable pole when a short-circuit current flows and cancels a closed state of the movable pole by the latch mechanism. The tripping mechanism is constituted by a pair of parallel conductors, one of which is arranged facing each other in a plane perpendicular to the moving direction of the movable pole and one of which can move along the moving direction of the movable pole. And

[0010] In the above configuration, by not providing the impedance, a short-circuit current interrupting device can be formed.

[0011] In the above two devices, the parallel conductor can be formed by a spiral conductor.

[0012]

In the above means, when a short-circuit current flows to the load side, the current flows to the pair of parallel conductors, and an electromagnetic repulsion is generated. This repulsive force moves the parallel conductor on the movable side, moving the movable pole away from the fixed pole, and simultaneously releasing the latch mechanism. Therefore, the movable pole is in the cutoff state. When the movable pole is cut off, impedance is inserted into the short circuit, and the short circuit current is suppressed.

[0013] Further, in the interrupting device having no impedance, the current is interrupted when the movable pole is turned off.

In the above, the length of the parallel conductor for obtaining the required electromagnetic repulsion becomes considerably long, but by forming it in a spiral shape, the size can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on an embodiment of a short-circuit current suppressing device shown in the drawings.

FIG. 1 is a right side view showing an embodiment of the present invention, and FIG. 2 is a left side view thereof omitting a current limiting resistor, both showing a normal energized state. FIG. 3 is a right side view of the operation state of the electromagnetic repulsion board, and FIG. 4 is a left side view showing the latch mechanism in an off state.

First, the configuration of the valve section will be described.
In FIG. 1, an insulating base 2 is mounted on a substrate 1, and a valve mounting bracket 3 is mounted on the insulating base 2. The fixed pole of the vacuum valve 5 is attached to the valve mounting bracket 3 with the fixed pole terminal 4 interposed therebetween. A movable pole terminal 6 and a connection shaft 7 are attached to a movable pole of the vacuum valve 5. The connecting shaft 7 passes through the hole of the movable insulating table 9,
The connection fitting 11 is attached to the tip.

Next, the structure of the repulsion board will be described.
In FIG. 1, a movable insulating table 9 is attached to a main shaft 10. The connection fitting 11 is connected to the repulsion shaft 13.
The repulsion shaft 13 passes through the repulsion board 16 and the repulsion board terminal 14 insulated. The repulsion board terminal 14 is tightened by bolts with the repulsion board 16 with the holding plate 15 interposed therebetween to be integrated. The holding plate 15 and the repulsion plate 16 are insulated by an insulating plate 17 except for the central portion. The repulsion board terminal 14 and the support frame 23 are insulated by the insulating plate 18. The operation panel 19 includes the repulsion shaft 13
To each other with a roll pin. The repulsion shaft 13 is the support frame 2
3 is supported through the insulating collar 22. A return spring 21 is mounted between the repulsion board terminal 14 ′ and the support frame 23 so as to cover the cushion material 20 and the operation board 19. In order to prevent the rotation of the repulsion board 16, the detent shaft 25 passes through the repulsion board 16, the holding plate 15 and the support frame 23. The support frame 23 and the substrate 1 are insulated by an insulating table 24.

FIG. 5 is a front view and a side view showing an example of the repulsion board 16.
4 is fixed with bolts and nuts.
b is connected to the opposing repulsion board 16 'by a lead wire 26. A spiral circuit is formed between the terminal mounting portions 16a and 16b by the groove 16c in order to increase the conductor distance.

Note that the electromagnetic repulsion force F of the unit length of the parallel conductor is
Is given by the following equation, where G is the distance between the centers of the parallel conductors.

F = 2.05 × (I _S ² / G) × 10 ⁻⁸ [kg / cm] Here, if G = 2 cm and I _S = 31.5 × 10 ³ A,
F = 10 kg / cm. Assuming that the electromagnetic repulsion force P required for tripping the movable pole of the vacuum valve is 2000 kg, the conductor length L is expressed by the following equation.

L = P / F = 2000/10 = 200 cm Since such a conductor length L is too long to be obtained by a linear conductor, the conductor plate is provided with a spiral groove to form a spiral conductor, thereby reducing the size. It is desirable to aim at.

Next, the configuration of the current limiting resistor will be described. The current limiting resistor mounting board 28 is coupled to the board 1. An insulating bush 29 is attached to the current limiting resistor mounting board 28, and the current limiting resistor terminal 34 is connected to the fixed pole terminal 4 and the movable pole terminal 6 by the lead wire 27 through the insulating bush. The current limiting resistor mounting frame 31 is mounted on the current limiting resistor mounting substrate 28 via the insulating base 30. The current limiting resistor plates 33 and the insulating plates 32 are alternately stacked on a predetermined number and attached to the current limiting resistor mounting frame 31. The overlapped current limiting resistance plates 33 are alternately welded at both ends and have a predetermined resistance value.

Next, the configuration of the latch release section will be described.
This will be described with reference to FIG. The main shaft 10 is rotatably attached to the substrate 1. The main arm 42 is attached to the main shaft 10 by welding. The main arm 42 is connected to the closing electromagnet 43. The latch plate support plate 44 is the latch plate 4
Supports 0. The roller 41 is attached to the latch plate 40. The main arm 42 is latched and held by the roller receiver 39, the latch plate 40, and the latch plate support plate 44. FIG. 2 shows a latch holding state. The roller receiver 39 is connected to the trip coil. The roller receiver 39 is the release plate 3
8, the trip arm 37, the trip arm shaft 36, and the trip plate 35 are connected to the repulsion board terminal 14 '. The trip arm shaft 36 is connected to the other phase.

The vacuum valve, the repulsion board, and the current limiting resistor are provided for three phases.

Next, the operation of the present embodiment will be described.

At the time of normal on-off operation On-off operation In the open state, the main arm 42 is in an open state by a blocking spring (not shown). Input electromagnet 43
Is turned on, the main arm 42 rotates, and the main shaft 10 rotates. When the main shaft 10 rotates, the movable insulating table 9 rotates,
The movable pole terminal 6 is pushed through the contact spring 8 and the vacuum valve 5 is turned on. When the main arm 42 completes the closing of the vacuum valve 5, the latch state is maintained by the roller receiver 39, the latch plate 40, and the latch plate support plate 44 as shown in FIG. Since the main arm 42 is in the latched state, the vacuum valve 5 maintains the closed state even when the excitation of the closing electromagnet 43 is released.

Disconnecting operation When the trip coil 45 is excited, the roller receiver 39 rotates and the roller 41 is not stopped, so that the main arm 42 is rotated by the breaking spring to the breaking completion point and stopped. The main shaft 10 and the movable insulating table 9 work with the main arm 42 to pull the vacuum valve 5 in the opening direction. Since the shut-off spring is always acting in the shut-off direction, the vacuum valve 5 is kept open.

When short-circuit current is supplied, the normal conduction path is as follows: lead wire 26 → fixed pole terminal 4 → vacuum valve 5 → movable pole terminal 6 → lead wire 26 → repulsion board terminal 14 → repulsion board 16 → lead wire 26 → Repulsion board 16 ′ → repulsion board terminal 14 ′ → lead wire 26. At this time, the vacuum valve 5 is in a contact pressure state of the contact spring 8.

When a short-circuit current flows, the repulsion disks 16, 16 '
Are the same spiral-shaped conductors, and have the same spiraling direction, so that the conductors are parallel conductors with opposite energizing directions, and a large electromagnetic repulsive force is generated between the repulsion disks 16, 16 '. . For example, in the case of a conductor distance of 20 mm and a parallel length of 2000 mm, the repulsive force 2 at a peak of 31.5 KA
000 kgf is obtained.

The repulsion board 16 is immovable in a state where it hits the support frame 23, so that the free repulsion board 16 'is
Open to 6. Next, the repulsion board 16 ′ strikes the operation board 19 and pushes the repulsion shaft 13. When the repulsion shaft 13 is pushed,
The movable pole of the vacuum valve 5 connected by the connection plate 12, the connection fitting 11, and the connection shaft 7 is separated. When the vacuum valve 5 is opened, the short-circuit current is cut off, and the current flows through the lead 27, the terminal 34, the current limiting resistor 33, the terminal 34 '→ the lead 27. Repulsion board 16 ', repulsion board terminal 1
4 'collides with the cushion material 20 via the operation panel 19 and rebounds. However, the repulsion disk 16' and the repulsion disk terminal 14 'are rebounded with respect to the repulsion shaft 13 in the direction in which the vacuum valve 5 is applied. Has no effect on the reinjection force.

Since the laminated portion of the current limiting resistor 33 has a resistance of 4.2Ω in this embodiment, the short-circuit current is limited to 1000 A. If the current is limited to 1000 A, the electromagnetic repulsion between the repulsion disks 16 and 16 'is reduced to such an extent that the repulsion disks 16 and 16' cannot be kept open, and the force for pushing the repulsion shaft 13 is almost eliminated. The contact spring 8 acts as a force for closing the vacuum valve 5, but the repulsion shaft 13, the connecting plate 1
2. It is absorbed by the open inertial force of the connecting fitting 11, the connecting shaft 7, the movable pole terminal 6, and the like, and there is a time delay before it acts. When the repulsion board terminal 14 'starts to move by the electromagnetic repulsive force, the tripping plate 35 directly connected to the repulsion board terminal 14' causes the roller receiver 3 via the tripping arm 37 and the tripping plate 38.
Pull 9 The latch state of the main arm 42 is released,
The main arm 42 is moved in the opening direction by a blocking spring (not shown), and stops when the opening is completed. Main arm 42
In the opening direction, the main shaft 10 and the movable insulating base 9 linked to the main arm 42 also move in the opening direction, and the opening is completed. Before the contact spring 8 acts on the throwing input, the movable insulating table 9 is opened, so that the throwing input of the contact spring 8 is released. The re-input of the vacuum valve 5 is performed by the input electromagnet 43.

FIG. 6 shows the state of short-circuit current interruption according to the present embodiment, and shows a change in current of a certain phase when a short-circuit current flows. When a short-circuit current flows, the repulsion disks 16, 1
Although the vacuum valve 5 is cut off by the electromagnetic repulsive force acting on 6 ', the current continues to flow through the arc even after the movable pole is opened, and when the AC zero point is reached within 1/2 cycle of the power supply frequency, the short-circuit current becomes Disappear.

In this manner, the short-circuit current is rapidly cut off (1/1) by the shut-off capability of the vacuum valve 5 by the electromagnetic repulsion.
(Within 2 cycles). The short-circuit current can be suppressed to 1000 A by the current limiting resistance of 4.2Ω. The reclosing of the vacuum valve can be prevented by the rebound caused by the breaking impact of the electromagnetic repulsion board. The overall size of the device is, for example, 800 × 8
The size is about 00 × 840 (mm ³ ) and the weight is about 150 kg, so that the size and weight can be reduced. Therefore, installation on a pillar becomes possible. In addition, repeated use has become possible. Since the arc region when the short-circuit current is interrupted is limited within the vacuum valve, it is not necessary to take a special insulating space as a circuit breaker. The magnitude of the impedance is determined by the value of the current and the time of the current.
A, If the energizing condition is about 0.4 seconds, the size may be as large as that described above. Depending on the energization conditions, it is conceivable that only the impedance is separately provided.

The above embodiment is a short-circuit current suppressing device. However, if the impedance, that is, the current limiting resistor 33 is not provided, the device becomes a short-circuit current interrupting device, and the short-circuit current can be interrupted in the same manner.

[0036]

As described above, according to the present invention, by providing the electromagnetic repulsion board, the electromagnetic repulsion force due to the short-circuit current can be effectively and easily taken out to withstand the contact pressure of the contact point of the vacuum valve during energization. Then, the vacuum valve is separated, and the short-circuit current can be cut off within 1/2 cycle. At the same time as the cut-off is completed, the short-circuit current is transferred to the impedance. it can. When the device is used as a breaking device without providing an impedance, the breaking of the short-circuit current can be completed within １ ／ cycle.

In the electromagnetic repulsion disk, the required length of the conductor can be accommodated in a narrow space by forming the spiral groove, so that the size and weight can be reduced.

[Brief description of the drawings]

FIG. 1 is a right side view showing an embodiment of the present invention.

FIG. 2 is a left side view in which a current limiting resistor is omitted.

FIG. 3 is a right side view of an operation state of the electromagnetic repulsion board.

FIG. 4 is a left side view showing the latch mechanism in an off state.

FIG. 5 is a front view and a side view showing an example of an electromagnetic repulsion board.

FIG. 6 is a time chart showing a current interruption state in the embodiment.

FIG. 7 is a block diagram showing a basic configuration of an apparatus according to the present invention.

[Explanation of symbols]

Reference Signs List 1 board, 2 insulating stand, 3 valve mounting bracket, 4 fixed pole terminal, 5 vacuum valve, 6 movable pole terminal, 7 connecting shaft, 8 contact spring, 9 movable insulating stand, 10 main shaft,
11 connecting bracket, 12 connecting plate, 13 repulsive shaft, 14
Repulsion board terminal, 15 holding plate, 16 repulsion board, 17, 18
Insulating plate, 19 operation panel, 20 cushion material, 21 return spring, 22 insulating collar, 23 support frame, 24
Insulation stand, 25 non-rotating shaft, 26, 27 lead wire,
28 current limiting resistor mounting board, 29 insulating bush, 30 insulating base, 31 current limiting resistor mounting frame, 32 insulating plate, 33 current limiting resistor plate, 34 terminal, 35 trip board, 36 trip arm axis, 37 trip arm , 38 release plate, 39 roller receiver, 40 latch plate, 41 rollers,
42 main arm, 43 closing electromagnet, 44 latch plate support plate

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Taketomi 1-1, Odaikita-cho, Saga City, Saga Prefecture Inside the Togami Electric Works, Ltd. (72) Inventor Hiroaki Nakayama 1-1, Oitakita-machi, Saga City, Saga Prefecture (56) References Japanese Patent Publication No. 3-59920 (JP, B2) Japanese Patent Publication No. 64-8887 (JP, B2) Japanese Patent Publication No. 59-42445 (JP, B2) (58) Field (Int.Cl. ⁶ , DB name) H01H 33/59 H01H 73/36

Claims (4)

(57) [Claims] 1. A switch, a latch mechanism for holding a movable pole of the switch in a closed state, an impedance connected between a fixed pole terminal and a movable pole terminal of the switch, and a short-circuit current flowing therethrough. A trip mechanism for opening the movable pole when the movable pole is opened and releasing the movable pole from the closed state by the latch mechanism, wherein the trip mechanism is perpendicular to the moving direction of the movable pole. A short-circuit current suppressing device characterized by comprising a pair of parallel conductors, one of which is arranged facing each other in a flat plane and which can move along the moving direction of the movable pole. 2. The short-circuit current suppressing device according to claim 1, wherein the parallel conductor is formed by a spiral conductor. 3. A switch, a latch mechanism for holding a movable pole of the switch in a closed state, and opening of the movable pole when a short-circuit current flows, and changing a closed state of the movable pole by the latch mechanism. A tripping mechanism for releasing the short-circuit current interrupter, wherein the tripping mechanism is disposed so as to face each other in a plane perpendicular to the moving direction of the movable pole, one of which is arranged in the moving direction of the movable pole. A short-circuit current interrupter comprising a pair of parallel conductors that can move along. 4. The short-circuit current interrupting device according to claim 3, wherein the parallel conductor is formed by a spiral conductor.