Switchgear

Abstract

To provide a switchgear with partition plate grade PM while securing an insulation strength even in the switchgear using a shutter having an existing nonmetal part.SOLUTION: A switchgear (1) comprises a shutter (4) having a nonmetal part covering circuit terminals (3, 33) in an enclosure (2) when a circuit breaker (9), which is a drawer type device, is pulled out of the connection position. In the switchgear (1) formed with partition plate grade PM, the shutter (4) has a metallic ground plate (12) grounded, securing an insulation strength.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In conventional switchgear, when a circuit breaker is pulled out from its housing for maintenance or inspection, the live parts that are normally housed inside are exposed to the outside. To protect workers entering the panel from electric shock, the live parts, that is, the main circuit terminals, are partitioned and covered with a structure such as a shutter. In this case, a shutter device has been proposed that uses an insulator to shorten the insulation distance and a composite material with a grounded metal on the outside to allow leakage current to escape, thereby achieving both a shortened insulation distance and a suppression of leakage current (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6995248 [Patent Document 2] Japanese Patent Application Publication No. 4-190607 Summary of the Invention [Problem to be solved by the invention]

[0004] The standard "JEM1425:2011," which conventional switchgear complies with, includes a classification for metal-clad switchgear. "JEM1425:2011" defines metal-clad switchgear as "switchgear in which each piece of equipment is placed in a compartment separated by grounded metal partitions (if non-metallic shutters and barriers are used, the respective regulations must be met)," and allows the use of not only metal partitions but also non-metallic partitions and shutters that meet the conditions set out in "JEM1425:2011," such as non-metallic partitions and shutters with a leakage current not exceeding 0.5 mA, so switchgear can be treated as metal-clad switchgear even when non-metallic partitions and shutters are used.

[0005] However, the standard will be replaced by "JIS C 62271-200:2021," which places emphasis on safety, maintenance, and inspectability. This JIS standard defines a new specification, LSC2B-PI / PM, in which all compartments are separated by grounded metal or non-metallic partitions, so that operators can safely perform maintenance and inspection work in other compartments (non-live sections) even when some compartments are live. Partition class PM is defined as "a class of switchgear equipped with grounded, continuous metal partitions and / or shutters (if necessary) between an open, accessible compartment and a high-voltage live section," while partition class PI is defined as "a class of switchgear equipped with one or more non-metallic partitions or shutters between an open, accessible compartment and a high-voltage live section."

[0006] Therefore, metal-clad switchgear using conventional non-metallic partitions and shutters can no longer be distinguished from partition grade PM and is treated as partition grade PI. This has created the problem that conventional metal-clad switchgear may experience problems if partition grade PM is required.

[0007] The present disclosure discloses a technology for solving the above-mentioned problems, and aims to provide a switchgear that can ensure insulation strength and be used as a partition plate class PM even when the existing shutter itself is made of a non-metal or when the switchgear uses a shutter with a non-metal plate or the like attached to a metal shutter. [Means for solving the problem]

[0008] The switchgear of the present disclosure comprises: A switchgear including a shutter having a non-metallic portion that covers a circuit terminal in a housing when a drawable device is drawn out from a connected position, The shutter is with a metal grounded ground plate It is something. [Effects of the Invention]

[0009] According to the switchgear of the present disclosure, Even in switchgear that uses shutters with existing non-metallic parts, insulation strength can be ensured and the product can be provided as a partition plate grade PM. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic side cross-sectional view showing the configuration of a switchgear according to a first embodiment. FIG. [Figure 2] Fig. 2A is a partial cross-sectional side view showing a state in which a circuit breaker is inserted into the switchgear shown in Fig. 1. Fig. 2B is a partial cross-sectional side view showing a state in which a circuit breaker is drawn out from the switchgear shown in Fig. 1. [Figure 3] 3 is a perspective view showing the configuration of a shielding plate and a ground plate of the shutter shown in FIG. 2. FIG. [Figure 4] 4 is a perspective view showing the attachment state of the shielding plate and the ground plate of the shutter shown in FIG. 3. FIG. [Figure 5] Fig. 5A is a perspective view showing the configuration of a shielding plate and an arm of a shutter of a switchgear according to embodiment 2. Fig. 5B is a perspective view showing a state in which a ground plate is attached to the shielding plate of the shutter shown in Fig. 5A. [Figure 6] FIG. 11 is a perspective view showing the configuration of a carriage that is moved in and out of a switchgear according to a third embodiment. [Figure 7] FIG. 7 is a schematic side cross-sectional view showing the configuration of the switchgear when the bogie shown in FIG. 6 is inserted. [Figure 8] 8 is a schematic front cross-sectional view showing the configuration of a part of the switchgear when the bogie shown in FIG. 7 is inserted. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiment 1 Fig. 1 is a schematic side cross-sectional view showing the configuration of a switchgear according to embodiment 1. Fig. 2A is a partial cross-sectional view showing a state in which a circuit breaker is inserted into the switchgear shown in Fig. 1. Fig. 2B is a partial cross-sectional view showing a state in which the circuit breaker is pulled out from the switchgear shown in Fig. 1. Fig. 3 is a perspective view showing the configuration of the shielding plate and grounding plate of the shutter shown in Fig. 2. Fig. 4 is a perspective view showing the attached state of the shielding plate and grounding plate of the shutter shown in Fig. 3.

[0012] As shown in Figure 1, the switchgear 1 has a housing formed with three independent compartments: a circuit breaker compartment 2, a busbar compartment 6, and a cable compartment 8. The circuit breaker compartment 2 is located on the front side of the switchgear 1, and is a room in which a circuit breaker 9 (see Figure 2) as an insertable, drawable device is housed and arranged, and the circuit breaker 9 (see Figure 2) is inserted and removed from the front side. The busbar compartment 6 includes a three-phase busbar 5 and a main circuit terminal 3 as a circuit terminal formed at one end of the three-phase busbar 5.

[0013] The cable compartment 8 is disposed behind and below the busbar compartment 6, and includes a load-side cable 7 and a cable circuit terminal 33 as a circuit terminal formed at one end of the cable 7. The main circuit terminal 3 and the cable circuit terminal 33 are installed in the high-voltage charging unit 14. When the circuit breaker 9 is inserted, the main circuit terminal 3 and the cable circuit terminal 33 are connected to the circuit breaker 9. When the circuit breaker 9 is pulled out, the metal shutter 4 is closed, completely separating the circuit breaker compartment 2 from the main circuit terminal 3 and the cable circuit terminal 33 (high-voltage charging unit 14).

[0014] As shown in Fig. 3, the shutter 4 includes a shielding plate 10 and a grounding plate 12 as non-metallic parts. The shielding plate 10 is made of a non-metallic material and separates the main circuit terminal 3 and cable circuit terminal 33 from the circuit breaker compartment 2 when the circuit breaker 9 is not inserted. On the surface of the shielding plate 10 opposite the main circuit terminal 3 and cable circuit terminal 33, there is provided a metallic grounding plate 12 that is in contact with the shielding plate 10 and is arranged to cover the shielding plate 10. The grounding plate 12 is arranged in a grounded state.

[0015] As shown in Fig. 2, the shutter 4 is configured to be moved up and down by a grounded metal arm 11. Note that the connection between the shutter 4 and the arm 11 is not shown in Fig. 2. The state shown in Fig. 2A shows the state in which the circuit breaker 9 is inserted, and the state shown in Fig. 2B shows the state in which the circuit breaker 9 is removed. Note that the grounded state of the arm 11 is not shown in each drawing. The arm 11 is configured to move in accordance with the removal or insertion of the circuit breaker 9 to open and close the shutter 4.

[0016] For this reason, as shown in Fig. 2A, when the circuit breaker 9 is inserted, the shutter 4 is moved downward by the arm 11 and controlled to an open state, connecting the main circuit terminal 3 and the cable circuit terminal 33 with the circuit breaker 9. Furthermore, as shown in Fig. 2B, when the circuit breaker 9 is pulled out, compared to Fig. 2A, the shutter 4 is moved upward by the arm 11 and controlled to a closed state, hiding the main circuit terminal 3 and the cable circuit terminal 33 and establishing the circuit breaker compartment 2. Note that the configuration of the arm 11 shown in Fig. 2 is just one example, and other configurations may be used as long as the opening and closing of the shutter 4 can be controlled in the same manner as described above.

[0017] As explained with reference to FIG. 3 , the shutter 4 has a grounded metallic ground plate 12 attached to it so as to cover the surface of the non-metallic shielding plate 10 opposite the main circuit terminal 3 and the cable circuit terminal 33. Note that the grounded state of the ground plate 12 is not shown in FIG. 3 . With this configuration, the ground plate 12 is located in front of the non-metallic shielding plate 10 in the circuit breaker compartment 2, and for safety during maintenance and inspection, a structure is achieved in which workers touch the ground plate 12 before the non-metallic shielding plate 10. Furthermore, workers will not come into contact with the high-voltage charging part 14. This allows workers to perform their work without any problems.

[0018] Another installation method for the ground plate 12 is to fasten the ground plate 120 to a grounded metal arm 11 via the shielding plate 10 using a metal fastening screw 13, as shown in Figure 4. This configuration ensures that the ground plate 120 is grounded via the screw 13 and the arm 11, ensuring zero potential and ensuring contact with the shielding plate 10, allowing for the same opening and closing operation as the shielding plate 10. This configuration ensures safety during maintenance and inspection, ensuring that workers touch the ground plate 12 before the non-metallic shielding plate 10. Furthermore, this prevents workers from touching the high-voltage charging part 14. This allows workers to perform their work without any problems. Therefore, the shutter 4 satisfies the requirements for metal partition plates and shutters in "JISC62271-200:2021" and can be considered a grounded, continuous metal shutter.

[0019] Furthermore, "JIS C 62271-200:2021" states, "Partition Class PM: Class for switchgear equipped with a grounded, continuous metal partition and / or shutter (if necessary) between an open, accessible compartment and a high-voltage live part." Therefore, by configuring the shutter 4 as in the present embodiment described above, in the switchgear 1 shown in FIG. 1, after the circuit breaker 9 is pulled out, the grounded ground plate 12 is in contact with the shielding plate 10 between the open, accessible circuit breaker compartment 2 and the main circuit terminal 3 and the cable circuit terminal 33 (high-voltage live part 14), resulting in a substantially continuous metal shutter 4. Therefore, the switchgear 1 can be treated as partition class PM rather than partition class PI.

[0020] According to the switchgear of the first embodiment configured as described above, A switchgear including a shutter having a non-metallic portion that covers a circuit terminal in a housing when a drawable device is drawn out from a connected position, The shutter is It is equipped with a metal grounded ground plate. It is composed of: Furthermore, according to the switchgear of the first embodiment configured as described above, The non-metallic portion of the shutter is a shielding plate made of a nonmetallic material on the circuit terminal side of the ground plate, The ground plate is disposed so as to cover the shielding plate. It is composed of: "JISC62271-200:2021" states, "Partition Class PM: Class for switchgear equipped with a grounded, continuous metal partition and / or shutter (if required) between an open, accessible compartment and a high-voltage live part." Therefore, by arranging the ground plate in contact with the non-metallic shielding plate as in the first embodiment, the ground plate is at zero potential, and in consideration of safety during maintenance and inspection, the structure allows workers to touch the ground plate before the non-metallic shielding plate.Furthermore, the structure also prevents workers from touching the circuit terminals. In addition, since the switchgear satisfies the requirements for metal partitions and shutters in "JISC62271-200:2021," it can be treated as a partition grade PM. Furthermore, even for metal-clad switchgear that uses existing non-metallic shielding plates, if a grounding plate is installed in the same way, the insulation strength can be ensured and the switchgear can be treated as partition plate class PM while maintaining its previous size.

[0021] Furthermore, according to the switchgear of the first embodiment configured as described above, a grounded metal arm for opening and closing the shutter; The ground plate is fastened to the arm via the shielding plate by a metal fastening part. So, The ground plate can be reliably installed on the shielding plate, and the ground plate can be reliably opened and closed in accordance with the opening and closing operation of the shielding plate.

[0022] Embodiment 2 Fig. 5A is a perspective view showing the configuration of the shielding plate and arm of the shutter of the switchgear according to embodiment 2. Fig. 5B is a perspective view showing a state in which a ground plate is attached to the shielding plate of the shutter shown in Fig. 5A. In each figure, the same parts as those in embodiment 1 above are given the same reference numerals.

[0023] In the above-mentioned first embodiment, an example was shown in which the switchgear 1 is made to be of partition plate class PM by fastening the ground plate 12 to the arm 11 that moves the shutter 4 via the non-metallic shielding plate 10. "JISC62271-200:2021" states, "An insertable partition plate may be used temporarily to prevent the fixed contacts from being exposed during charging. If the partition plate and shutter between the opened compartment and other high-voltage live parts are made of metal, the class shall be PM."

[0024] 5A, in the case of shielding plate 10 installed on arm 11 via screw 131 as a metal fastening part, the top surface of screw 131 appears on the side of shielding plate 10 opposite main circuit terminal 3 and cable circuit terminal 33. Then, during maintenance and inspection, a detachable metal grounding plate 121 made of, for example, tape is temporarily attached so that it comes into contact with the top surface of screw 131. With this configuration, switchgear 1 can be made to meet partition plate class PM.

[0025] As in the first embodiment, the ground plate 121 is attached to cover the surface of the shielding plate 10 opposite the main circuit terminal 3 and the cable circuit terminal 33. Therefore, as shown in FIG. 5, the ground plate 121, which is temporarily attached during maintenance and inspection, is attached in contact with the screw 131 that is electrically continuous with the arm 11, and is connected to the grounded arm 11 via the screw 131, so that the ground plate 121 is at zero potential. In consideration of safety during maintenance and inspection, the structure is such that a worker touches the ground plate 121 before the shielding plate 10. Furthermore, the structure is such that the worker is prevented from touching the high-voltage charging portion 14 of the main circuit terminal 3 and the cable circuit terminal 33.

[0026] As a result, the shutter 4 satisfies the requirements for metal partition plates and shutters in "JISC62271-200:2021" and can be considered a grounded, continuous metal shutter. In addition, because the ground plate 121 is temporarily attached to the shielding plate 10 with tape or the like, it can be attached more easily and in less time than with fastening parts such as screws. Furthermore, because the ground plate 121 is temporarily attached to the shielding plate 10 with tape or the like, the ground plate 121 can be removed when maintenance and inspection are complete. Furthermore, by removing the ground plate 121 when maintenance and inspection are complete, there is no need to worry about it falling off and durability is not required, making it possible to realize the switchgear 1 at low cost.

[0027] The switchgear of the second embodiment configured as described above has the same effects as those of the first embodiment, and also has the following advantages: The ground plate is formed so as to be detachable from the shielding plate. It is composed. JISC62271-200:2021 states, "Temporary insert partitions may be used to prevent the fixed contacts from being exposed during charging. If the partitions and shutters between the open compartment and other high-voltage charging parts are made of metal, the classification shall be PM." Therefore, as in the second embodiment, by attaching a detachable metallic ground plate to a non-metallic shielding plate and temporarily using it during maintenance and inspection, the ground plate becomes zero potential, and for safety during maintenance and inspection, a structure is created in which workers touch the ground plate before the non-metallic shielding plate, and further, touching the circuit terminals can be prevented. In addition, even switchgear that uses non-metallic shielding plates can be converted to partition plate class PM. By preparing a grounding plate that can be used temporarily and then removed when maintenance and inspection are complete, the grounding plate can be installed in a short time and then removed when maintenance and inspection are complete, eliminating the need to worry about it falling off and requiring durability, making it possible to inexpensively convert switchgear from partition plate class PI to partition plate class PM.

[0028] Embodiment 3 Fig. 6 is a perspective view showing the configuration of a carriage that is inserted into and removed from the switchgear according to embodiment 3. Fig. 7 is a schematic side cross-sectional view showing the configuration of the switchgear when the carriage shown in Fig. 6 is inserted. In Fig. 7, the left side of the paper is the front. Fig. 8 is a schematic front cross-sectional view showing the configuration of a part of the switchgear when the carriage shown in Fig. 7 is inserted. In each drawing, parts that are the same as those in the above embodiments are given the same reference numerals.

[0029] In the above-described second embodiment, an example has been described in which a detachable ground plate 121 is temporarily attached during maintenance and inspection to make the switchgear 1 a partition plate class PM. In the third embodiment, as shown in Fig. 6, an empty cart 15 is used that does not carry a circuit breaker 9 equipped with a metal ground plate 122. Then, as shown in Fig. 7, the cart 15 is temporarily inserted during maintenance and inspection, and the ground plate 122 is brought into contact with the screws 131 of the shielding plate 10 of the shutter 4.

[0030] Therefore, by making the shutter 4 between the circuit breaker compartment 2 and the main circuit terminal 3 and cable circuit terminal 33 (high voltage charging section 14) substantially out of metal due to the presence of the ground plate 122 of the bogie 15, the switchgear 1 can be treated as a partition plate class PM. In consideration of safety during maintenance and inspection, the bogie 15 equipped with the ground plate 122 is configured so that an operator will touch the ground plate 122 before the shielding plate 10, as shown in Figure 8.

[0031] As in the second embodiment, the ground plate 122 comes into contact with the screw 131 that is electrically continuous with the arm 11. As a result, the ground plate 122 is connected to the grounded arm 11 via the screw 131, and the ground plate 122 is at zero potential. Therefore, in consideration of safety during maintenance and inspection, the structure is such that an operator touches the ground plate 122 before the shielding plate 10. Furthermore, the structure is such that the operator does not come into contact with the main circuit terminal 3 and the cable circuit terminal 33 (high-voltage charging section 14). The switchgear 1 satisfies the requirements for metal partition plates and shutters in "JISC62271-200:2021" and can be considered to be made of a grounded, continuous metal.

[0032] The bogie 15 is temporarily inserted into the circuit breaker compartment 2 during maintenance and inspection. Therefore, if a bogie 15 equipped with the grounding plate 122 is prepared in advance, the same bogie 15 can be used repeatedly for other maintenance and inspection. Because it is temporarily inserted, it can be completed more easily and in a shorter time than fastening with screws or the like, and since it can be used repeatedly, there is no need to prepare parts for each maintenance and inspection, and the only necessary expense is the initial cost. Therefore, the switchgear 1 can be realized inexpensively.

[0033] The switchgear of the third embodiment configured as described above has the same effects as those of the above embodiments, and also has the following advantages: The ground plate is disposed on a carriage that can be inserted into and removed from the housing. So, By providing a ground plate mounted on a bogie that can be used temporarily and retrieved when maintenance and inspection are completed, the ground plate can be installed in a short time, and by retrieving the ground plate when maintenance and inspection are completed, there is no need to worry about it falling off, and durability is not required, so it is possible to change the switchgear from partition plate class PI to partition plate class PM at low cost.

[0034] In each of the above embodiments, an example is shown in which the circuit breaker is pulled out from the housing, but this is not limited to this, and the same can be done when the circuit breaker is pulled out from the connection position, and the same effect can be achieved.

[0035] Furthermore, in the above embodiments, the shutter is made of metal, but the shutter mechanism may have an arm made of metal and an insulating shutter attached thereto, eliminating the need for a shielding plate.

[0036] Furthermore, in each of the above embodiments, a circuit breaker has been shown as an example of a draw-out type device inserted into a switchgear, but the draw-out type device is not limited to this, and may be, for example, a disconnecting switch, an instrument transformer, or the like.

[0037] While the present disclosure 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 exemplified are conceivable within the scope of the technology disclosed in this 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]

[0038] 1. Switchgear, 2. Circuit breaker compartment, 3. Main circuit terminal, 33 Cable circuit terminal, 4 Shutter, 5 Three-phase busbar, 6 Busbar compartment, 7 cable, 8 cable compartment, 9 circuit breaker, 10 shielding plate, 11 arm, 12 ground plate, 120 ground plate, 121 ground plate, 122 ground plate, 13 screws, 131 screws, 14 high voltage charging part, 15 trolley.

Claims

1. A switchgear including a shutter having a non-metallic portion that covers a circuit terminal in a housing when a drawable device is drawn out from a connected position, The shutter is Switchgear with a metal earthed earth plate.

2. The non-metallic portion of the shutter is a shielding plate made of a nonmetallic material on the circuit terminal side of the ground plate, The switchgear according to claim 1 , wherein the ground plate is disposed so as to cover the shielding plate.

3. a grounded metal arm for opening and closing the shutter; The switchgear according to claim 2 , wherein the ground plate is fastened to the arm via the shielding plate by a metal fastening portion.

4. The switchgear according to claim 2 , wherein the ground plate is formed so as to be detachable from the shielding plate.

5. The switchgear according to claim 1 , wherein the ground plate is disposed on a carriage that can be moved in and out of the housing.

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