Switchgear

Abstract

To solve a problem in which an arc space of a switch gear is not sufficiently attached to a housing, and the arc space may fall off or be damaged.SOLUTION: Since a metal plate that constitutes an arc space is fastened to a housing with a metal bolt via an insulator, the dielectric strength of the arc space is improved and the arc space can be fastened to the housing with sufficient tightening torque.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present application relates to switchgear. [Background technology]

[0002] A structure is known in which the arc space of a DC circuit breaker is formed by an insulating plate, and this insulating plate is attached to a housing (see, for example, Patent Documents 1 and 2). The arc space is described as an arc extinguishing chamber 3 in Patent Document 1 and as an arc barrier 3 in Patent Document 2, but both documents describe it as a large box-shaped space for extinguishing the arc during circuit breaking, and it is thought that it has the same function as the arc space described in this application. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 60-138305 [Patent Document 2] Japanese Patent Application Publication No. 59-103504 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to make switchgear more compact, the housing itself tends to be made smaller, and the arc space is also being reduced. With this configuration, when the DC circuit breaker is interrupted, the pressure of the hot gas (gas that is conductive at high temperatures) that the insulating plate that makes up the reduced arc space is subjected to becomes greater than before, and there is a risk that the insulating plate may be damaged.

[0005] Furthermore, in a structure in which the arc extinguishing chamber 3 is attached to the housing by engaging an angle with a hook, as in Patent Document 1, or in a structure in which the arc barrier 3 is attached to the housing by engaging angles with each other, as in Patent Document 2, vibrations caused by the pressure of the hot gas can loosen or disengage the engagement, which could cause the arc extinguishing chamber 3 or the arc barrier 3 to fall off or be damaged.

[0006] To prevent this, it is conceivable to fix the arc space formed by the insulating plate to the housing with insulating bolts, but insulating bolts are weaker than regular steel bolts and cannot be tightened with sufficient torque. As a result, a rise in pressure inside the arc space causes stress to concentrate at the insulating bolt fastening points, which could cause the insulating bolts to loosen or break.

[0007] The present application has been made to solve the above-mentioned problems, and has an object to provide a switchgear having improved dielectric strength and an arc space that is fastened to a housing with sufficient tightening torque. [Means for solving the problem]

[0008] The switchgear disclosed in the present application has an arc space disposed in the housing for discharging hot gas generated when a DC circuit breaker is interrupted to the outside of the panel, and a metal plate serving as a side plate of the arc space The metal plates are separated into the front and rear, and an insulating plate connects the front and rear metal plates. , fixed to the housing with metal bolts via insulators been There are Characterized by . [Effects of the Invention]

[0009] According to the switchgear disclosed in the present application, the metal plates constituting the arc space are fastened to the housing with metal bolts via insulators, which improves the dielectric strength of the arc space and enables the arc space to be fastened to the housing with sufficient tightening torque. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a switchgear according to a first embodiment. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is a structural diagram of an arc space of the switchgear according to the first embodiment. [Figure 4] FIG. 2 is an enlarged view of the upper part of the cross section BB in FIG. [Figure 5]FIG. 10 is a structural diagram of an arc space of a switchgear according to a second embodiment. [Figure 6] FIG. 10 is a structural diagram of an arc space of a switchgear according to a third embodiment. [Figure 7] FIG. 10 is a structural diagram of an arc space of a switchgear according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiment 1 FIG. 1 is a perspective view of the switchgear according to the first embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. The switchgear 100 is configured by accommodating devices in a partitioned space within a housing 1. That is, a DC circuit breaker (hereinafter referred to as a circuit breaker) 2 is accommodated in the housing 1 so that it can be pulled out toward the front side of the page, and an arc space 3 is attached to the housing 1 above the circuit breaker 2.

[0012] The arc space 3 surrounds the arc extinguishing chamber 21 attached to the circuit breaker 2, with its sides made of metal plates 31a, 31b, 31c, 31d and insulating plates 32a, 32b, and its front and back made of metal plates 31e, 31f and insulating plates 32c, 32d. The arc space 3 extends to the ceiling of the housing 1, where a ventilation tower 11 with an exhaust port is provided. Behind the circuit breaker 2, bus conductors 4 and various cables 5 are stored.

[0013] A face plate 22 is attached to the front of the circuit breaker 2, and is provided with a handle for pulling out the circuit breaker 2, a hole for inserting a manual closing handle for manually closing the circuit breaker 2, and a hole for attaching a handle for moving the circuit breaker 2 body between the test position and the connection position.

[0014] Fig. 3 is a structural diagram of the arc space in Fig. 1, and Fig. 4 is an enlarged view of the upper part of the B-B cross section in Fig. 1. In the arc space 3, the front metal plate 31a on the upper side and the rear metal plate 31b on the upper side are connected by a strip-shaped insulating plate 32a, and the front metal plate 31c on the lower side and the rear metal plate 31d on the lower side are connected by an insulating plate 32b, thereby forming an insulating separation between the front and rear conductive barriers by the metal plates and preventing restriking of the DC circuit breaker.

[0015] The area around the hot gas outlet of arc extinguishing chamber 21 in arc space 3 is surrounded by insulating plate 32b at the front of the arc space, insulating plate 32c at the side, and insulating plate 32d at the rear, all of which have larger areas than insulating plate 32a, to surround arc extinguishing chamber 21 and improve insulation. Metal plates 31c and 31d are stacked and arranged to surround the outside of insulating plate 32b, and are fastened together with metal bolts 7. As a result, it is the metal plates that are fastened to housing 1 via insulators 6, and the insulating plates are not fastened directly to housing 1, which prevents damage to the insulating plates when they are attached to housing 1.

[0016] Immediately after the DC circuit breaker is turned off, the arc space 3 temporarily has electrical conductivity due to the hot gas, so the arc space 3 is at an intermediate potential relative to the grounded housing 1 to ensure strength to the ground. For this reason, as shown in Figure 4, the frame 8 of the housing 1 and the arc space 3 are fastened together with metal bolts 7 such as iron bolts via insulators 6. This allows the insulators 6 that insulate and support the arc space 3 to increase the creepage length and strengthen the dielectric strength.

[0017] As a method for insulating and isolating the metal plates 31a and 31b, it is possible to arrange a columnar insulating material between the metal plates 31a and 31b and fix this columnar insulating material to the housing 1. However, in the case of a columnar insulating material, the columnar insulating material is fixed directly to the housing 1, rather than being fixed to the housing 1 via an insulator. This results in an insufficient creepage length, which may create a ground fault path.

[0018] As described above, in this embodiment, 3As shown in Fig. 1, metal plates 31a, 31b, 31c, and 31d, which constitute the side plates of arc space 3, are fixed to housing 1 via insulators 6 (circled by dashed lines). This eliminates any differences in dielectric strength between arc space 3 and housing 1, allowing for uniformly strengthened dielectric strength. Furthermore, metal plates 31a and 31b are connected by insulating plate 32a, and metal plates 31c and 31d are connected by insulating plate 32b, ensuring reliable insulation and isolation of the conductive barrier. Furthermore, metal plates 31a, 31b, 31c, and 31d are fixed to housing 1 via insulators 6 with metal bolts 7, allowing for fastening with sufficient torque to prevent loosening or damage to the bolts due to pressure buildup within arc space 3. While metal plates 31a and 31b and insulating plate 32a, or metal plates 31c and 31d and insulating plate 32b, are fastened together with metal bolts 7, this is not a limitation.

[0019] Embodiment 2 figure 5 1 is a perspective view showing an arc space 3a of a switchgear 100 according to Embodiment 2. Description of parts having the same configuration as the arc space 3 of Embodiment 1 will be omitted. In the first embodiment, insulating plate 32b is disposed around the upper portion of circuit breaker 2 to improve insulation, but insulating separation may also be achieved by disposing strip-shaped insulating plate 32a from the top to the bottom of arc space 3a and connecting metal plates 31a, 31b, metal plates 31c, 31d, metal plates 31g, 31h to insulating plate 32a. This reduces the area of insulating plates used and reduces costs.

[0020] Like the insulating plate 32b in the first embodiment, the metal plates 31g and 31h may be configured to cover only the top of the circuit breaker 2, or may be configured to cover the sides of the circuit breaker 2 from top to bottom so as to reliably prevent hot gas from being released outside the arc space in the housing 1. This is particularly effective when fins are attached to the circuit breaker 2.

[0021] Embodiment 3 figure 6is a perspective view showing an arc space 3b of a switchgear 100 according to embodiment 3. The configuration is the same as that of embodiment 1 except for the insulating plate 32d. By covering the side of the circuit breaker 2 with two insulating plates 32d rather than covering the side of the circuit breaker 2 with a structure in which metal plates 31g and 31h are connected by a strip-shaped insulating plate 32a as in embodiment 2, the configuration can be simplified, the number of parts can be reduced, and insulation can be improved.

[0022] Embodiment 4 figure 7 FIG. 10 is a perspective view showing the arc space 3c of the switchgear 100 according to the fourth embodiment. As in the second embodiment, the structure is such that a strip-shaped insulating plate 32a is arranged from the top to the bottom of the arc space 3a, and metal plates 31a, 31b, 31c, 31d, 31g, and 31h are connected to insulating plate 32a to provide insulation and separation. In addition, a frame is attached to the front metal plate 31e via insulators, and a control panel is arranged on top of the frame. This makes it possible to arrange some of the control devices (e.g., relays 9, etc.) of the control panel, which cannot be arranged in the control room due to the miniaturization of the switchgear, in front of the arc space.

[0023] Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are conceivable within the scope of the technology disclosed in the present specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment. [Explanation of symbols]

[0024] 1: Housing, 2: DC circuit breaker, 3, 3a, 3b, 3c: Arc space, 4: Bus conductor, 5: Cable, 6: Insulator, 7: Metal bolt, 8: Frame, 9: Relay, 31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h: Metal plate, 32a, 32b, 32c, 32d: Insulating plate, 100: Switchgear

Claims

1. In a switchgear in which an arc space is disposed within a housing to exhaust hot gas generated when a DC circuit breaker is interrupted to the outside of the panel, the metal plates that are the side plates of the arc space are disposed separately in a front portion and a rear portion, the front and rear metal plates are connected by an insulating plate, and the metal plates are fixed to the housing with metal bolts via insulators.

2. The switchgear according to claim 1, wherein the insulating plate is fastened together with the metal plate by a metal bolt.

3. A switchgear in which an arc space, which discharges hot gas generated when a DC circuit breaker is shut off, is arranged inside a housing, the metal plates which are the side plates of the arc space being fixed to the housing with metal bolts via insulators, the metal plates being arranged in separate upper front and upper rear parts, and lower front and lower rear parts of the arc space, the metal plates of the lower front and lower rear parts being located around the arc extinguishing chamber of the DC circuit breaker, the upper front and upper rear metal plates being connected from the inside by a first insulating plate, and the lower front and lower rear metal plates being connected from the inside by a second insulating plate, the switchgear being characterized in that the area of the second insulating plate is larger than the area of the first insulating plate.

4. The switchgear according to claim 3 , wherein the first insulating plate and the second insulating plate are fastened together with the metal plate by metal bolts.

5. The switchgear according to any one of claims 1 to 4, wherein an insulating plate is disposed below the metal plate.

6. The switchgear according to any one of claims 1 to 5, wherein a control device is arranged on a metal plate in front of the arc space via an insulator.

Images