JPH0395816A - Gas-circuit breaker - Google Patents

Abstract

PURPOSE:To efficiently cool an arc to improve breaking performance by making a space outside an arc driving coil opened toward both sides of an axial direction in a pressure raising chamber. CONSTITUTION:When a movable contact 26 comes off a fixed contact 17 with a breaking instruction, an arc is generated between the two, and when the tip of the contact 26 reaches a nozzle 15 side, the arc transfers to a rotating electrode 23 so that an arc A is generated between a rotating plate 18 and the electrode 23 to cause gas in a pressure raising chamber 16 to be heated and expanded resulting in a rapid increase of gas pressure in the chamber. If the tip of the contact 26 is positioned lower than a rotating electrode 24, an arc A' is generated between the two, and arc current is flowed to a driving coil 20 so that its magnetic flux interlinks with the arcs A, A' resulting in high speed rotation of the respective arcs along the electrodes 23, 24 so that gas is blown against the respective arcs. When the contact 26 comes off the nozzle 15, gas in the chamber 16 is discharged through the nozzle 15 and gas is strongly blown against the arc A' resulting in elimination of the arc at a current zero point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas circuit breaker that uses both an arc rotation type arc extinguishing method and a self-expansion type arc extinguishing method.

C. Prior Art As arc extinguishing methods for cogas circuit breakers, there are known arc extinguishing methods: an arc rotation type arc extinguishing method and a self-expansion type (auto expansion type) arc extinguishing method.

The arc rotation type arc extinguishing method links the magnetic flux generated from the arc drive coil excited by the arc current with the arc, rotates the arc at high speed in arc extinguishing gas, and sprays gas relative to the arc. This method extinguishes the arc by

In addition, the self-expansion type arc extinguishing method has a pressure boosting chamber that surrounds the arc generation space, and the gas in the boosting chamber, whose pressure has increased due to self-expansion due to the powerful energy of the arc, is ejected from an insulated nozzle to generate high-speed gas. The arc is extinguished by generating a gas flow and spraying the gas flow onto the arc.

Figures 6 and 7 show a conventional gas circuit breaker that uses both an arc rotation type arc extinguishing system and a self-expansion type arc extinguishing system, with Figure 6 showing the closed state and Figure 7 indicates a blocked state.

In these figures, 1 is a cylindrical cylinder for forming a pressurization chamber, and 2 is
3 is a disk-shaped fixed contact side conductor attached to airtightly close the top end of the cylinder 1; 3 is an insulating plate attached to airtightly close the bottom of the cylinder 1; An insulating nozzle 4 is formed in the insulating nozzle 4. An external terminal (not shown) is connected to the fixed contact side conductor 2.

A pressurization chamber 5 is constituted by a cylinder 2 for forming a pressurization chamber, a conductor 2, and an insulating plate 3.

An annular fixed contact 6 is connected to the center of the inner surface of the conductor 2, and an arc drive coil 7 is arranged so as to concentrically surround the fixed contact.

One end of the arc drive coil 7 is electrically connected to the conductor 2, and the other end of the coil is electrically connected to an annular arc rotating electrode 8 disposed coaxially with the fixed contact.

Reference numeral 9 denotes a movable contact that enters and exits the pressurization chamber 5 through the nozzle 4, and this movable contact has two positions: as shown in FIG. and the cutoff position where the nozzle 4 is separated from the nozzle 4 by a distance of . The movable contact is electrically connected via a current collector to a movable contact side conductor (not shown) provided at a fixed location, and an external terminal is connected to the movable contact side conductor.

The above-mentioned parts constitute the main part of the interrupter, and the interrupter is housed in a circuit breaker container filled with SF6 gas.

When the above circuit breaker is in the closed state shown in Fig. 6,
A seed circuit current flows through a path of the fixed contact side conductor 2, the fixed contact 6, the movable contact 9, and the movable contact side conductor (not shown).

When the movable contact 9 is moved up and down in the drawing to separate it from the fixed contact 6 in order to open the circuit breaker, an arc At is generated between both contacts.

From the moment this arc contacts the arc rotating electrode 8, a current flows through the arc drive coil 7, and the coil is excited.

Since the magnetic flux generated from this coil interlinks with the arc AI, rotational force is applied to the arc, and the arc A1 rotates at high speed along the arc rotating electrode 8. As a result, gas is blown relative to the arc At, thereby cooling the arc.

Furthermore, since the gas in the boosting chamber 5 rapidly expands due to the strong energy of the arc, the pressure in the boosting chamber 5 increases while the movable contact 9 is fitted into the nozzle 4.

When the movable contact 9 is removed from the nozzle 4, the gas in the pressurizing chamber 5 is ejected through the nozzle 4, creating a high-speed gas flow. Since this gas flow is blown onto the arc A2, the arc is further cooled and extinguished at the zero point of the current.

[Problem to be Solved by the Invention] During the period when the movable contact 9 is fitted into the nozzle 4 in the process of shutting off the gas circuit breaker, the gas around it rotates with the high speed rotation of the arc Al. , is moved radially outward by centrifugal force. The gas moved radially outward flows into the space Q outside the arc drive coil 7 and increases the pressure in the space Q, but this space Q is closed at one end in the axial direction (conductor 2 side). Moreover, since the gas moved by the centrifugal force from the arc A1 side is flowing into the space Q, when the movable contact 9 leaves the nozzle 4, the gas in the space Q is immediately transferred to the nozzle. I couldn't get it to flow out from 4. Therefore, it is difficult to intensify the gas blow against the arc immediately after the movable contact 9 leaves the nozzle 4, and this has been one of the reasons for hindering the improvement of the interrupting performance.

The purpose of the present invention is to improve the breaking performance by strengthening the blowing of gas against the arc when the movable contact leaves the insulating nozzle, and by stirring the ionized gas and fresh gas well. An object of the present invention is to provide a gas circuit breaker that can achieve the following objectives.

[Means for Solving the Problems] The circuit breaker of the present invention is shown in FIGS.
As seen in the figure, the pressurization chamber l with an insulated nozzle 15
6, a fixed contact 17 provided in the pressurizing chamber while sharing an axis with the insulating nozzle, and a fixed contact 17 disposed coaxially with the fixed contact in a gas space located between the fixed contact in the pressurizing chamber and the insulating nozzle. an arc drive coil 20; first and second arc rotations disposed coaxially with the arc drive coil and electrically connected to an end on the fixed contact side and an end on the insulating nozzle side of the arc drive coil, respectively; electrodes 23 and 24, and a movable contact 26 that is displaced between a closing position in which it contacts the fixed contact through a passage including the inside of the insulated nozzle and the inside of the arc drive coil, and a cut-off position in which it separates from the fixed contact and leaves the insulated nozzle. We are prepared.

Insulating means 25 can be provided inside the arc drive coil to insulate the movable contact from the arc rotating electrode.

As can be seen in FIGS. 4 and 5, it is also possible to connect a contact 28 with a movable contact in sliding contact with the second arc rotating electrode 24'. In this case, the movable contact 26 is electrically connected to the second arc rotating electrode until it is detached from the second arc rotating electrode.

[Operation] In the above gas circuit breaker, when the movable contact separates from the fixed contact, an arc occurs between both contacts. When the tip of the movable contact moves further toward the second arc rotating electrode than the first arc rotating electrode, the arc moves to the first arc rotating electrode. The energy of this arc heats the gas in the pressurization chamber and causes it to expand.

At this time, the movable contact is fitted into the insulating nozzle and the pressurization chamber is substantially sealed, so the ionized gas near the arc flows as shown by arrow q in Figure 3 and enters the pressurization chamber. It is mixed with fresh gas Q in 16 and forced into the nozzle part 15.

This causes the pressure inside the pressurization chamber to rise rapidly. When the movable contact moves further and the tip of the movable contact reaches a position closer to the insulated nozzle than the second arc rotating electrode, an arc is also generated between the movable contact and the second arc rotating electrode.

From the moment this state occurs, current flows to the arc drive coil, and the magnetic flux generated from the arc drive coil becomes the first
The arc rotates at high speed along the first arc rotating electrode and the second arc rotating electrode, respectively, because it interlinks with the arc generated on the arc rotating electrode side and the second arc rotating electrode side, respectively.

When the movable contact moves further toward the cutoff position and is removed from the insulating nozzle, the gas in the pressurizing chamber is ejected from the insulating nozzle all at once, and the gas is sprayed onto the arc. The arc is cooled by both the relative gas blowing performed by high-speed rotation and the gas blowing ejected from the pressurization chamber through an insulated nozzle, and is extinguished at the current zero point.

When the arc drive coil is placed in the space between the fixed contact and the insulated nozzle as described above, the space outside the arc drive coil becomes a space open on both sides in the axial direction within the booster chamber, so the movable contact is insulated. The moment the gas is removed from the nozzle, the gas in each part of the pressurizing chamber is smoothly guided to the insulated nozzle, allowing a large amount of gas to flow out at once from the gas insulated nozzle. Further, the gas pressure in the pressurizing chamber can be sufficiently increased by the preceding arc generated on the side of the first arc rotating electrode. Therefore, it is possible to intensify the gas blow against the arc at the moment when the movable contact comes off the insulating nozzle, and the synergistic effect of this gas blow and the relative gas blow that occurs as the arc rotates at high speed suppresses the arc. It can be effectively cooled to improve interrupting performance.

[Example] Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figures 1 to 3 show the main parts of the cut-off section of the first embodiment of the present invention. Figure 1 is a longitudinal sectional view showing the closed state, and Figure 2 is the - 3 is a vertical sectional view showing the cut-off state.

In these figures, reference numeral 11 denotes a cylindrical body for forming a pressurization chamber made of an insulating material or a conductive material.

In this embodiment, a cylindrical body 11 is made of an insulating material, and a plate-shaped portion 12a of an annular conductor 12 is hermetically connected to one end of this cylindrical body. A cylindrical protrusion l2b protruding toward the side opposite to the cylinder 11 is provided at the center of the annular conductor 12, and a conductive plate 13 is attached to airtightly close the end of the protrusion 12b.

An insulating plate 14 is connected to the other end of the cylinder 11.
An insulating nozzle 15 that shares an axis with the cylinder 11 is provided at the center of the cylinder 4 . Cylindrical body 11, annular conductor 12, and conductive plate 1
3 and the insulating plate 14 constitute a boosting chamber 16.

A rear end portion of an annular fixed contact 17 that shares an axis with the insulating nozzle 15 is connected to the inner surface of the conductor l3. The fixed contact 17 has its tip connected to the plate-shaped portion 1 of the annular conductor 12.
A contact portion 17a is provided inside the tip portion of the fixed contact. The tip of the fixed contact 17 and the plate-shaped portion 12a of the annular conductor
A disc-shaped arc rotating plate 18 is fixed across the inner surface of the arc plate 18. This rotary plate l8 is made of an arc-resistant conductive material such as W-Cu sintered alloy, and has a fixed contact 1 in its center.
A hole 18a having an inner diameter slightly larger than that of No. 7 is provided.

An arc drive coil 20 is arranged coaxially with the fixed contact 17 in the gas space between the fixed contact 17 and the insulating nozzle 15 in the boosting chamber 16 . This arc drive coil 20 is arranged in a support tube 21 made of an insulating material, and the support tube 21 is arranged in support arms 2 that are radially provided.
It is supported on the inner surface of the cylindrical body 11 via 2.

An annular first arc rotating electrode 23 is electrically connected to the fixed contact side end of the arc drive coil 20, and a second arc rotating electrode 24 is electrically connected to the insulated nozzle side end. The first arc rotating electrode 23 has a plate-shaped portion 2
3a and a cylindrical portion 23b,
The plate-shaped portion 23a is arranged along the end surface of the arc drive coil 20 on the fixed contact side. The second arc rotating electrode 24 is made of an annular plate, and is arranged along the end surface of the arc drive coil 20 on the insulated nozzle side. First and second arc rotating electrodes 2
3 and 24 are made of an arc-resistant conductive material like the arc rotating plate 18.

In this embodiment, an insulating sleeve 25 is arranged inside the arc drive coil 20, and this insulating sleeve 25 allows the second
The inner periphery of the arc rotating electrode 24 and the inner periphery of the arc drive coil are insulated.

26 is a rod-shaped movable contact, and this movable contact connects the space inside the insulating nozzle 15 and the arc drive coil 20.
The first
It is provided so as to be displaced between a closed position where it contacts the fixed contact 17 as shown in the figure, and a shut off position where it is separated from the fixed contact and separated from the insulating nozzle as shown in FIG. In this example, the first arc rotating electrode 23
The inner diameter of the cylindrical portion 23b is formed slightly smaller than the inner diameter of the insulating sleeve 25, and the movable contact 26 is
It is designed so that it does not come into direct contact with the arc rotating electrode 23.

In order to prevent the pressure in the pressurizing chamber 16 from rising when the movable contact 26 is turned on, which would hinder the closing of the movable contact, the movable contact 26 is fitted into the nozzle l5 relatively loosely, or the arc It is desirable that the inside and outside of the pressurization chamber 16 be communicated through a communication passage that is small enough not to interfere with the rise in pressure within the pressurization chamber 16 at the time of occurrence.

The above-mentioned parts constitute the main parts of the interrupter, and the interrupter is housed in a breaker container (not shown) filled with SF6 gas.

When the above circuit breaker is in the closed state shown in Figure 1,
Conductive plate 13 - fixed contact 17 - movable contact 26
The main circuit current flows through the − path.

When a cutoff command is given and the movable contact 26 separates from the fixed contact 17, an arc is generated between both contacts. When the tip of the movable contact 26 reaches a position below the first arc rotating electrode 23 (on the nozzle 15 side), the arc moves to the arc rotating electrode 23 and the arc rotating plate 18 and the arc rotating electrode 23 are connected. Arc A occurs between. The energy of this arc A heats and expands the gas within the pressurizing chamber 16, causing the gas pressure within the pressurizing chamber to rise rapidly.

The tip of the movable contact 26 is the second arc rotating electrode 24
When reaching a position lower than , an arc A' is generated between the movable contact 26 and the second arc rotating electrode 24,
Arc current flows through the arc drive coil 20. As a result, a magnetic flux is generated from the arc drive coil, and this magnetic flux interlinks with the arcs A and A-, so a rotational force is applied to the arcs A and A-, and these arcs are connected to the arc rotating electrode 23.2.
Rotate at high speed along 4. As a result, gas is blown relative to the arcs A and A-.

When the movable contact 26 separates from the insulating nozzle 15,
Since the gas in the pressurization chamber 16 is released through the insulating nozzle 15 all at once, the gas is strongly blown onto the arc A'.
The arc disappears at the current zero point.

FIGS. 4 and 5 show a shut-off section according to a second embodiment of the present invention, with FIG. 4 showing a closed state and FIG. 5 showing a shut-off state. In FIGS. 4 and 5, the same parts as those in the embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the insulated nozzle 1 of the arc drive coil 20
An annular contact holding conductor 27 is connected to the end of the 5 side, and a contact 2 made of a tulip contact is connected to this conductor 27.
8 is installed.

A bowl-shaped second arc rotating electrode 24' is attached to the outer periphery of the contact holding conductor 27 so as to cover the contact 28. The movable contact 26 inserted into the pressurizing chamber 5 through the insulating nozzle 15 contacts the fixed contact 17 through the space inside the arc drive coil 20 while maintaining contact with the contact 28 . Other points are first
The structure is similar to that of the embodiment shown in FIGS.

In this embodiment, since the movable contact 26 is electrically connected to the nozzle side end of the arc drive coil 20 via the contactor 28, the tip of the movable contact 26 is connected to the first end.
When moving below the arc rotating electrode 23, the fixed contact 17 - the arc rotating plate 18 - the arc A-first
A current flows through the arc drive coil through the arc rotating electrode 23 - arc drive coil 20 - contactor 28 - movable contact 26, and the coil is excited. As a result, magnetic flux is generated from the arc drive coil 20 and interlinks with the arc A, so that the arc A rotates between the first arc rotating electrode 23 and the arc rotating plate 18.

As the arc rotates, the gas in the R part in the pressurizing chamber 16 rotates with the arc, is stirred with fresh gas Q by centrifugal force and thermal expansion due to arc energy, and is pushed into the second arc rotating electrode 24 part. . As a result, the pressurization chamber 16
The gas pressure inside increases rapidly.

When the movable contact 26 separates from the contactor 28, an arc A' is generated between the second arc rotating electrode 24' and the movable contact 26; Rotate. Other operations are similar to those in the previous embodiment.

According to the embodiment shown in FIGS. 4 and 5, the arc generated between the first arc rotating electrode 23 and the arc rotating plate 18 is transferred between the second arc rotating electrode and the movable contact. Since it is possible to rotate at high speed before the arc A' is generated, the interrupting performance can be further improved than in the first embodiment.

[Effects of the Invention] As described above, according to the present invention, the arc drive coil is disposed in the space between the fixed contact and the insulating nozzle, and the space outside the arc drive coil is spaced on both sides in the axial direction within the boosting chamber. Because it is an open space, the moment the movable contact comes off the insulating nozzle, the gas in each part of the pressurizing chamber is smoothly guided to the insulating nozzle side, and a large amount of gas can flow out from the gas insulating nozzle at once. Further, the gas pressure in the pressurizing chamber can be sufficiently increased by the preceding arc generated on the side of the first arc rotating electrode. Therefore, it is possible to intensify the gas blow against the arc at the moment when the movable contact comes off the insulating nozzle, and the synergistic effect of this gas blow and the relative gas blow that occurs as the arc rotates at high speed suppresses the arc. It has the advantage of being able to effectively cool and improve interrupting performance.

[Brief explanation of drawings]

Figures 1 to 3 show the main parts of the cut-off part of the embodiment of the first step of the present invention, where Figure 1 is a longitudinal cross-sectional view showing the closed state, and Figure 2 is the section shown in Figure 1. ■A line sectional view, FIG. 3 is a vertical sectional view showing the shut-off state, and FIGS. FIG. 6 and FIG. 7 are longitudinal sectional views showing the closed state and the closed state of the interrupting section of a conventional circuit breaker, respectively. 11... Cylindrical body for boosting chamber structure, 12... Annular conductor, 1
3... Conductive plate, 14... Insulating plate, ■5... Insulating nozzle, 16... Boosting chamber, 17... Fixed contact,
18... Arc rotating plate, 20... Arc drive coil, 21... Support tube, 22... Support arm, 23... First arc rotating electrode, 24... Second arc rotating Electrode, 25... Insulating sleeve, 26... Movable contact. Figure 1 Figure 5 Figure 3 Figure 4 Figure 6 Figure 7

Claims (3)

[Claims] (1) A pressurization chamber equipped with an insulated nozzle, a fixed contact provided in the pressurization chamber while sharing an axis with the insulated nozzle, and a gas space located between the fixed contact and the insulated nozzle in the pressurization chamber. an arc drive coil disposed coaxially with the fixed contact; and an electrically conductive coil disposed coaxially with the arc drive coil at an end on the fixed contact side and an end on the insulating nozzle side of the arc drive coil, respectively. first and second arc rotating electrodes connected to each other; a closing position in which the fixed contact is contacted through a passage including the inside of the insulated nozzle and the inside of the arc drive coil; and a cut-off position in which the fixed contact is separated from the insulated nozzle. A gas circuit breaker characterized by comprising a movable contact that is displaced between positions. (2) The gas circuit breaker according to claim 1, wherein an insulating means for insulating the movable contact from the second arc rotating electrode is provided inside the arc drive coil. (3) The gas circuit breaker according to claim 1 or 2, wherein a contact element with which the movable contact makes sliding contact is connected to the second arc rotating electrode.