JPH04363825A - Switch - Google Patents

Abstract

PURPOSE:To enhance power of a grounded switch for GIS against electromagnetic induction current. CONSTITUTION:The movable contact of the ground switch is constituted of movable main contacts 5 connected to movable electrodes 6, and movable commuting contacts 9 having higher resistance than the main contacts 5. An arc spot generated from an arc horn during contact parting operation, is commuted from the contacts 5 to the contacts 9. According to this construction, metal vapor discharged to a gap between the electrodes 6 before current breaking can be reduced, and insulation recoverability after current breaking can be improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc extinguishing chamber for a switch.

0002

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional example of a grounding switch for GIS. In FIG. 4, a fixed electrode 1 is connected to a tulip contact 2 and an arc horn 3, which are fixed contacts. The fixed electrode 1, tulip contact 2, and arc horn 3 are shielded by a fixed shield 4. The movable main contact 5 is moved up and down by an operation member (not shown) to move between a closed position and an open position. The movable side electrode 6 is connected to the movable main contact 5, and the movable side electrode 6 is shielded by a movable side shield 7.

[0003] In the above-mentioned conventional grounding switch for GIS, the electromagnetic induction current is cut off when the arc generated between the electrodes is
This is achieved by natural cooling by F6 gas and by increasing the distance between the electrodes to improve dielectric strength.

0004

[Problem to be Solved by the Invention] Since the conventional grounding switch for GIS is constructed as described above, during the arc generation period, the tip of the electrode is heated and melted by the arc spot, and metal vapor is emitted from the tip of the electrode. Released during the arc. In an ordinary grounding switch where there is almost no flow of insulating gas, the metal vapor remains between the electrodes and is difficult to diffuse, so the insulation recovery characteristics immediately after the current is interrupted deteriorates as the interrupting current increases.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to improve the electromagnetic induction current interrupting ability of a grounding switch for GIS, for example.

[0006]

[Means for Solving the Problems] A switch according to the present invention includes a fixed side contact and an arc horn connected to a fixed side electrode on a fixed side of the switch, and a movable side contact and an arc horn connected to a fixed side electrode on a movable side of the switch. a movable main contact that is connected to the fixed side contact in a closed state, and a relationship that is relatively closer to the fixed side contact than the movable main contact after the middle of the process where the movable main contact opens from the fixed side contact. A high-resistance commutation movable contact is provided, which is placed at a position such that the movable main contact is connected to the movable main contact.

[0007]

[Effect] As the distance between the arc horn and the movable main contact increases during opening operation, the arc spot moves to the tip of the high-resistance commutation movable contact, reducing the amount of metal vapor released between the electrodes. At the same time, the current is limited by the high resistance of the contact.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a GIS earthing switch according to the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows the state immediately after opening. FIG. 2 is a diagram at the moment when the arc spot moves to the movable contact for commutation and the stepped portion 5a of the movable main contact 5 engages with the stepped portion 9a of the movable contact for commutation 9. FIG. 3 shows a state in which the electrode opening operation is completed.

In FIG. 1, the fixed side is the same as the conventional example. On the movable side, a commutation movable contact 9 is coupled to the outer periphery of the movable main contact 5 so as to generate a frictional force, and the commutation movable contact 9 is coupled to the movable side shield 7 with a friction greater than the above friction. The movable commutation contact 9 is made of a material with a high melting point and high resistance, such as stainless steel. Therefore, when opening the operating member (not shown), the movable main contact 5 until the stepped portion 5a of the movable main contact 5 engages with the stepped portion 9a of the commutation movable contact 9
After the step portion 5a engages with the step portion 9a, the commutation movable contact 9 moves downward together with the movable main contact 5. The other configurations on the movable side are the same as the conventional example.

The operation of the embodiment will be explained below. In the closed state, current flows from the fixed electrode 1 through the fixed tulip contact 2 and the movable main contact 5 to the movable electrode 6, but in the state shown in FIG. An arc 10 is generated from the arc 1 through the arc horn 3 and flows to the movable main contact 5. As the opening progresses, the movable main contact 5 enters the movable contact for commutation 9, so that the arc 10 is commutated to the movable contact for commutation 9. Since the commutation movable contact 9 does not need to be energized in the closed state, it has a built-in high resistance and is made of a material with a high melting point, such as stainless steel, so after commutation, the metal vapor released from the arc spot The amount decreases and the arc is extinguished. As the electrode opening progresses further, the step portion 5a of the movable main contact 5 engages with the step portion 9a of the movable commutation contact 9, and both the movable main contact 5 and the movable commutation contact 9 move downward to reduce the distance between the electrodes. 3 and move to the open position shown in FIG.

In the above embodiment, the friction between the movable main contact 5 and the movable commutation contact 9 is made smaller than the friction between the movable commutation contact 9 and the movable shield 7. Therefore, the movable main contact 5 enters inside the commutation movable contact 9, the step 5a of the movable main contact 5 engages the step 9a of the commutation movable contact 9, and then the commutation movable contact 9 moves. be. In addition to the above configuration, methods other than frictional engagement may be used as long as they perform the same operations as above.

In the above embodiment, the commutation movable contact 9 is provided outside the movable main contact 5, but the commutation movable contact 9 may be provided inside the movable main contact 5.

[0013] In the above embodiment, a GIS earthing switch has been described, but a disconnector or other switch can also produce similar effects.

[0014]

As described above, according to the present invention, since the arc generated between the electrodes when opening is commutated from the movable main contact 5 to the commutation movable contact having a higher resistance, the current can be interrupted. The amount of metal evaporation released between the electrodes before heating can be reduced. Therefore, it has the effect of improving insulation recovery characteristics after current interruption.

[Brief explanation of drawings]

[Fig. 1] A cross-sectional view showing the GIS grounding switch immediately after opening according to an embodiment of the present invention.

[Figure 2] Cross-sectional view showing the middle of opening of the embodiment in Figure 1

[Figure 3]
A cross-sectional view showing the final open state of the embodiment shown in FIG.

FIG. 4 is a sectional view of a conventional GIS earthing switch.

[Explanation of symbols]

1 Fixed side electrode 2 Fixed side contact 3 Arch horn 5 Movable main contact 6 Movable side electrode 9 Movable contact for commutation

Claims (2)

[Claims] 1. A fixed side contact and an arc horn connected to a fixed side electrode on the fixed side of the switch, movably connected to the movable side electrode on the movable side of the switch,
A movable main contact contacts the fixed side contact in a closed state, and is placed at a position where the movable main contact is relatively closer to the fixed side contact than the movable main contact after the middle of the process of opening from the fixed side contact. A switch comprising a high resistance movable commutation contact connected to the movable main contact. 2. The switch according to claim 1, wherein the movable contact for commutation is made of a material with a high melting point and high resistance.