Gas-insulated switchgear

Abstract

The objective of this invention is to provide a structure suitable for use as a gas-insulated switchgear when using an alternative gas to SF6 gas. The gas-insulated switchgear of this invention includes a pressure vessel, electrical contacts disposed within the pressure vessel, and an insulating gas filling the pressure vessel, wherein the cross-sectional shape of the pressure vessel is curved.

Description

Technical Field

[0001] This invention relates to a gas-insulated switch device. Prior Technology

[0002] As a switching device, a gas-insulated switchgear is known to achieve high-voltage operation by using an insulating gas as the insulating medium. Previously, SF6, known for its high-performance properties, was widely used as the insulating gas. However, the ozone layer depletion caused by fluorinated gases has become a social problem, leading to a demand for switchgear that can achieve high-voltage operation without using Freon gases.

[0003] Patent document 1 studies the miniaturization of machines when using alternative gases to SF6 gas. [Previous Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2006-352972 Summary of the Invention

[0005] [The problem that the invention aims to solve] Patent Document 1 describes a switching device that studies the miniaturization of the machine, but its study remains at the level of detail and does not delve into a thorough study of the overall structure.

[0006] In order to solve the above-mentioned problems, the present invention provides a structure of an ideal gas-insulated switchgear when using an alternative gas to SF6 gas. [Technical means to solve the problem]

[0007] If we take as an example one of the safe operating devices of the present invention used to solve the above-mentioned problems, it is as follows.

[0008] The gas-insulated switchgear has a pressure vessel, electrical contacts disposed within the pressure vessel, and insulating gas filling the pressure vessel, wherein the cross-sectional shape of the pressure vessel is curved. [Effects of the Invention]

[0009] According to the present invention, a structure suitable for use as a gas-insulated switchgear is provided when using an alternative gas to SF6 gas.

[0010] Further details and effects of the present invention will be made clear by the following full description. Simple Explanation of the Diagram

[0011] Figure 1 is a schematic cross-sectional view of an example of the gas-insulated switchgear of the present invention. Figure 2 is a top view of an example of the gas-insulated switchgear of the present invention. Figure 3 is a side view of an example of the gas-insulated switchgear of the present invention. Figure 4 is a rear view of an example of the gas-insulated switchgear of the present invention. Figure 5 is a front view of an example of the gas-insulated switchgear of the present invention. Figure 6 is an explanatory diagram of the base plate of an example of the gas-insulated switchgear of the present invention. Figure 7 is an explanatory diagram of the base plate of an example of the gas-insulated switchgear of the present invention. Implementation

[0012] [Example 1] Figure 1 is a schematic cross-sectional view of an example of the gas-insulated switchgear of the present invention.

[0013] 10 is the busbar compartment, and 12 is the machine compartment. Together, they form tank 11. Pressurized dry air is sealed in both the busbar compartment 10 and the machine compartment 12. This is an example of a substitute gas for SF6. Furthermore, the substitute gas used is not limited to pressurized dry air, provided that it does not exhibit ozone-depleting properties.

[0014] Furthermore, the insulation performance per unit volume of dry air is inferior to that of SF6. To compensate for this, in this embodiment, the dry air is pressurized and sealed in at a gas pressure of 0.31 MPa. This gas pressure is higher than that used when SF6 is typically employed. This substantially increases the amount of gas per unit volume, thereby mitigating the difference in insulation characteristics caused by the change in insulating gas.

[0015] The problem here is the point at which the gas pressure must be increased, or more specifically, increased. Therefore, the gas pressure applied to the tank increases, requiring a thicker and heavier tank to withstand this pressure. Patent Document 1 also partially studies the miniaturization of the machine when using alternative gases, but a thorough study of the tank body itself is insufficient.

[0016] There are two simple solutions. One is to increase the size of the tank. However, this contradicts another societal requirement for miniaturization. The other is to increase the wall thickness of the tank. However, this leads to an increase in the number of components used and the energy used during handling and manufacturing, which, from another perspective, leads to a deterioration in environmental characteristics.

[0017] Therefore, the most significant feature of this invention is that the construction of the groove is changed from the previously common rectangular shape to a curved surface.

[0018] Figure 2 first illustrates the concept of the invention. Details will be described later, but its major feature is that the channel 11 has a curved surface structure, which, compared to a rectangular structure, i.e., one with extensive corners, can alleviate the concentration of gas pressure and thus increase the pressure resistance per unit area compared to a rectangle. As a result, the channel can be miniaturized or its wall thickness reduced. It is described here as a curved surface, but ideally, a circular shape is preferred. Therefore, the following description will use a circular shape as an example.

[0019] Returning to Figure 1, let's continue with the description of the internal structure of the gas-insulated switchgear. Furthermore, in this embodiment, the built-in mechanism itself does not require a special dedicated design. This is also one of the advantages of the invention in this application.

[0020] The busbar compartment has a side input / output section 19. A first input / output terminal 41 is inserted into a groove 11 from the side input / output section 19. The opening of the side input / output section 19 is firmly fixed and sealed by an insulating resin component, such as epoxy resin.

[0021] The current introduced from the first input / output terminal 41 is introduced into the circuit breaker 20 through the wire 40. The circuit breaker 20 drives either of the pair of first electrodes 21 by the drive unit, thereby controlling the conduction and interruption of the current by their contact and separation.

[0022] The current introduced by the circuit breaker 20 is introduced into the vacuum interrupter 22 through the conductor 40. This is a device that controls the conduction and interruption of current in a space that is maintained in a vacuum state by the contact and separation of a pair of electrodes.

[0023] Furthermore, conductor 40 extends from busbar compartment 10 to machine compartment 12, but a spacer 14 is provided in between to provide airtight separation between busbar compartment 10 and machine compartment 12. Moreover, this spacer 14 is insulated. This is to prevent the fault from spreading to other compartments in the event of a short circuit or other fault in either busbar compartment 10 or machine compartment 12, thereby preventing the fault from escalating.

[0024] Current flows through conductor 40 via vacuum interrupter 22 and is introduced to circuit breaker 23. Circuit breaker 23 drives either of the pair of second electrodes 24 by a drive unit, controlling the conduction and interruption of current by their contact and separation. The current that is conducting through circuit breaker 23 flows through conductor 40 to the second input / output terminal 42. In this way, the current of the gas-insulated switchgear is turned on and off.

[0025] One of the first input / output terminal 41 and the second input / output terminal 42 is an input, and the other is an output. Their names and functions vary depending on the method of use. Alternatively, one can be called the power source side and the other the power consumption machine side.

[0026] Furthermore, Figure 1 shows a grounding switch 25. This is used to drive either of the pair of third electrodes 26 to set the entire device to ground potential.

[0027] Furthermore, surge arrester 27 is disclosed. While it appears to be always connected in the diagram, it is characterized by the use of a special insulator that exhibits conductivity only at high voltages. Zinc oxide is an example. By using this, a configuration is achieved where, although formally connected, it is normally electrically insulated, but conducts under extremely high voltages such as lightning strikes. This device is used to prevent damage to machinery by releasing the high voltage to the ground potential connected to the front end of the surge arrester in the event of an accidental high voltage such as a lightning strike.

[0028] The structure of slot 11 will be further explained using Figure 1. 15 is the first circular hatch, and 16 is the second circular hatch. The first circular hatch 15 is larger than the second circular hatch 16. This is because the second input / output terminal 42 needs to be connected at the first circular hatch 15, especially since three terminals are required when the second input / output terminal 42 is three-phase. Therefore, it is larger than the second circular hatch 16 to ensure the required insulation distance between the terminals.

[0029] The second circular hatch 16 is primarily for inspection or machine installation during manufacturing. Therefore, it is not essential if other methods are used instead. However, it is ideal to have it installed considering the actual work environment or maintenance needs.

[0030] The groove 11 has a first rectangular hatch 17 and a second rectangular hatch 18 on the side opposite to the first circular hatch 15.

[0031] The second rectangular hatch 18 is used to house the circuit breaker 20 in the hatch of the slot 11. The first rectangular hatch 17 is used to house the drive unit of the circuit breaker 23 and the vacuum interrupter 22 in the hatch of the slot 11.

[0032] Here, it is evident that the first rectangular hatch 17 is larger when comparing the first rectangular hatch 17 and the second rectangular hatch 18. Therefore, from the perspective of pressure response to increased gas pressure, the study of the first rectangular hatch 17 becomes more important.

[0033] Therefore, in this invention, starting with the curved surface of the slot 11, a study is conducted on the ideal configuration for dealing with the increase in gas pressure, taking into account the shape or size of the hatch.

[0034] As a result, the inventors of this application discovered that the greater the maximum width of the opening in the lateral direction, the greater the pressure that can be applied through the hatch.

[0035] Therefore, in this invention, as a further configuration, in a gas-insulated switchgear having multiple hatches, a configuration is adopted where the width of the hatch in the lateral direction increases, and the wall thickness of the hatch is also increased. For example, the first circular hatch 15, relative to a circle of 830 mm (i.e., a lateral width of 830 mm), has a wall thickness of 32 mm. Furthermore, the first rectangular hatch 17, relative to a lateral width of 590 mm, has a wall thickness of 9 mm. Thus, in a gas-insulated switchgear using dry air with enhanced pressurization, safety is ensured even with hatches, and wall thickness reduction is achieved in some areas, resulting in weight reduction and improved environmental characteristics due to reduced component capacity.

[0036] Furthermore, the evaluation results indicate that, based on the pressure resistance of the groove, the difference in maximum width in the longitudinal direction has a smaller impact than the difference in maximum width in the transverse direction. Although the exact reason is not clearly determined, it is presumed that when using a circular groove, the transverse cross-section changes continuously, making it more susceptible to the effects of gas pressure or shape differences. In contrast, since the longitudinal cross-section is uniform and does not change, it is currently presumed to be less affected by gas pressure or shape differences.

[0037] Using Figure 2 (top view), we will continue with the construction description. Furthermore, since the component with the same symbol as in Figure 1 is the same component, further explanation is omitted.

[0038] The 45 series base plate, viewed from above, is exposed from the groove 11, particularly at its corners. In Figure 2, the first input / output terminals 41 are grouped into three pairs. They are respectively positioned at the top and bottom of the figure. However, there are also cases where only one is provided.

[0039] Also, in the diagram, 17 is hidden below 18. Similarly, in the diagram, 22 and 23 are hidden below 20.

[0040] The first circular hatch 15 has an opening and closing door 55 shown on its front surface. Furthermore, the figures in this specification also include various hatches that do not have separately shown opening and closing doors, but actually have opening and closing doors.

[0041] Figure 3 is a side view of an example of the gas-insulated switchgear of the present invention. Furthermore, since the component with the same symbol as in Figure 1 is the same component, further explanation is omitted. Compared to the cross-sectional view in Figure 1, because the slot 11 is circular, it is shown that each hatch is formed in the slot 11 in a manner that meanders into the side.

[0042] Figure 4 is a rear view of an example of the gas-insulated switchgear of the present invention. It corresponds to the view of the shape of Figure 1 from the right side. Furthermore, since the component with the same symbol as that in Figure 1 is the same component, further explanation is omitted. It can be seen that the first circular hatch 15 is larger than the second circular hatch 16.

[0043] Figure 5 is a front view of an example of the gas-insulated switchgear of the present invention. It corresponds to the view of the shape of Figure 1 from the left. Furthermore, since the components with the same symbol as those in Figure 1 are the same components, further explanation is omitted.

[0044] Figure 6 is an explanatory diagram of the base plate of an example of the gas-insulated switchgear of the present invention. Because the groove 11 is circular, it has the structural feature of creating a larger space at the corner of the base plate 45. Therefore, mounting holes 59 are provided using this larger space. This not only simplifies the installation process but also eliminates the need to ensure additional space for providing mounting holes, further enabling miniaturization.

[0045] Figure 7 is a variation of Figure 6. Observing Figure 6, it can be seen that there is still space in the direction of the mounting hole 59 leading to the slot 11. Therefore, in Figure 7, the mounting hole 59 is designed as an elongated hole leading to the slot 11. This facilitates positioning during combined operations or setup operations, thereby improving work efficiency or reducing time.

[0046] The aforementioned technical concepts can be used individually or in combination. Such applications are also included within the scope of this invention.

[0047] Furthermore, any variations or slight differences in structure that apply the technical concepts detailed above are also included within the scope of this invention.

[0048] The invention disclosed in this specification, for example, is as follows.

[0049] <Part 1> A gas-insulated switchgear includes a pressure vessel, electrical contacts disposed within the pressure vessel, and insulating gas filling the pressure vessel. The aforementioned pressure vessel has a curved cross-sectional shape.

[0050] <Part 2> Such as the gas-insulated switchgear in <Part 1>, in which The aforementioned curved surface is circular.

[0051] <Part 3> Such as the gas-insulated switchgear in <Part 2>, in which... The aforementioned insulating gas system is made of pressurized dry air.

[0052] <Part 4> Such as the gas-insulated switchgear in <Part 3>, in which... The aforementioned pressure vessel has a switch hatch, which is a circular hatch.

[0053] <Part 5> For example, the gas-insulated switchgear in section 4, its It has a rectangular hatch, which is different from the aforementioned circular hatch.

[0054] <Part 6> Such as the gas-insulated switchgear in <Part 5>, in which... The width of the aforementioned rectangular hatch in the lateral direction is narrower than that of the aforementioned circular hatch, and the wall thickness is thinner.

[0055] <Part 7> Such as the gas-insulated switchgear in <section 6>, in which... The wider the lateral width of the aforementioned rectangular hatch or the aforementioned circular hatch, the thicker the wall thickness.

[0056] <Part 8> Such as the gas-insulated switchgear in <Part 5>, in which... The aforementioned rectangular hatch is for mounting drive components, and the size of the parts mounted on the aforementioned rectangular hatch is larger than the size of the parts mounted on the aforementioned circular hatch.

[0057] <Part 9> Such as the gas-insulated switchgear in <Part 3>, in which... The aforementioned pressure vessel has a rectangular base on its lower surface, with mounting holes provided at the corners of the base.

[0058] <Part 10> Such as the gas-insulated switchgear in <No. 9>, in which... The aforementioned mounting hole is an elongated hole leading to the aforementioned pressure vessel.

[0059] 10: Busbar compartment 11: Slot 12: Machine Room 14: Spacer 15: First circular hatch 16: Second circular hatch 17: First rectangular hatch 18: Second rectangular hatch 19: Side Input / Output Section 20: Circuit breaker 21: A pair of first electrodes 22: Vacuum interrupter 23: Circuit breaker 24: A pair of second electrodes 25: Grounding switch 26: A pair of third electrodes 27: Surge arrester 40: Wire 41: First input / output terminal 42: Second Input / Output Terminal 45: Base Plate 55: Opening and closing doors 56: Opening and closing doors 59: Mounting Hole

Claims

1. A gas-insulated switchgear, comprising a pressure vessel, an electrical contact disposed within the pressure vessel, and an insulating gas filling the pressure vessel, wherein the cross-sectional shape of the pressure vessel in the transverse direction is curved; the pressure vessel has a switch hatch in the portion of the cross-sectional shape having the curved surface, and the switch hatch is circular; the pressure vessel has a rectangular hatch different from the circular hatch; and the wider the transverse width of the rectangular hatch or the circular hatch, the thicker the wall.

2. The gas-insulated switchgear as claimed in claim 1, wherein the aforementioned curved surface is circular.

3. The gas-insulated switchgear as claimed in claim 2, wherein the aforementioned insulating gas system is pressurized with dry air.

4. The gas-insulated switchgear as claimed in claim 1, wherein the width of the rectangular hatch in the lateral direction is narrower than that of the circular hatch, and the wall thickness is thinner.

5. The gas-insulated switchgear as claimed in claim 1, wherein the aforementioned rectangular hatch is for mounting the drive component, and the size of the part mounted on the aforementioned rectangular hatch is larger than the size of the part mounted on the aforementioned circular hatch.

6. The gas-insulated switchgear as claimed in claim 3, wherein the aforementioned pressure vessel has a rectangular base on its lower surface, and mounting holes are provided at the corners of the base.

7. The gas-insulated switchgear as claimed in claim 6, wherein the aforementioned mounting hole is an elongated hole leading to the aforementioned pressure vessel.

Images