JP5379279B2 - Gas insulated electrical equipment - Google Patents

Description

  The present invention relates to a gas-insulated electric device in which a high-voltage conductor is housed in a ground tank, and the ground tank is filled with an insulating gas so as to insulate the high-voltage conductor from the ground tank. The present invention relates to a structure that captures foreign matter that enters a tank.

  In a conventional gas-insulated electric apparatus, a high-voltage conductor is housed in a ground metal tank, and the tank can be insulated by filling it with an insulating gas. In this case, when assembling a gas-insulated electrical device, metal foreign matter may enter the tank, and the metal foreign matter will rise and adhere to the high-voltage conductor due to the strong electric field generated when the high-voltage conductor is energized. The withstand voltage performance of the device may deteriorate due to or approaching. Therefore, in order to prevent a decrease in withstand voltage performance due to the floating of the metal foreign object, a structure for capturing the metal foreign object is usually installed in the gas-insulated electric apparatus.

  As a structure for capturing metal foreign objects in a conventional gas-insulated electric device, a concave opening is formed in the bottom of a metal container, and an adhesive substance is applied to the opening and the vicinity thereof. There is one that captures metal foreign matter with a chemical substance (see Patent Document 1).

  In addition, one or more metal rods are arranged in the same direction as the axial direction of the tank at the bottom of the tank containing the high voltage conductive portion, and the surface of the metal rod is covered with an insulating coating, and this metal rod is connected to the tank. Some have provided a particle collector for capturing particles in a low electric field portion in contact (see Patent Document 2).

Japanese Patent Laid-Open No. 05-091630 (page 2 right 28 to page 2 right 31 line, FIG. 1) Japanese Utility Model Publication No. 56-145313 (page 3, page 14, page 4, line 4, FIGS. 5-6)

  Since the conventional gas-insulated electrical device is configured as described above, in the gas-insulated electrical device disclosed in Patent Document 1, the depth of the opening and the opening that are factors that determine the electric field in the opening. The relationship between the width of the metal and the size of the metal foreign object is not specified, and the strength of the electric field at the portion where the metal foreign object captured in the opening is located is sufficient to prevent the metal foreign object from floating due to electrostatic force However, there is a problem that when the adhesive substance is deteriorated and the adhesive strength is lowered, the metal foreign matter floats up and approaches the high voltage conductor, and the withstand voltage performance may be lowered.

  Further, in the gas insulated electric device disclosed in Patent Document 2, metal foreign matter captured by a low electric field portion composed of a metal rod and a tank is generated by transporting or operating the device. There is a problem in that it jumps up or moves due to vibration and moves to a place where the electric field is high, and floats due to the electrostatic force generated by the applied voltage, thereby lowering the withstand voltage performance.

  The present invention has been made to solve the above-described problems, and can reliably capture the metal foreign matter in the gas-insulated electric apparatus, and the adhesive material may be deteriorated or the apparatus may be vibrated. It is an object of the present invention to provide a gas-insulated electric device that can reliably capture captured foreign metal particles without causing them to float again.

  A gas-insulated electric apparatus according to the present invention comprises a ground tank filled with an insulating gas and a high-voltage conductor installed in the ground tank via an insulating spacer, and a metal is provided at the bottom of the ground tank. A recess is provided to form a low electric field portion that does not allow foreign matter to float, and an adhesive layer is provided only in the low electric field portion of the recess, and the width of the recess is d, the depth is h, and the length of the metal foreign matter When the thickness is L and α = (h−L) / d, the concave portion is formed so that α is 0.8 or more.

  According to the gas-insulated electric apparatus according to the present invention, the grounded tank is filled with an insulating gas, and includes a high-voltage conductor installed in the grounded tank via an insulating spacer, and the bottom of the grounded tank Are provided with a recess for forming a low electric field portion so that the metal foreign matter does not float, and an adhesive layer is provided only on the low electric field portion of the recess, the width of the recess is d, the depth is h, and the metal foreign matter is provided. When the length of L is α and α = (h−L) / d, since the concave portion is formed so that α is 0.8 or more, the metal foreign matter is in a position of a low electric field that does not float by electrostatic force. The metal foreign object does not float, and the metal foreign object is reliably captured by the trapping force of the adhesive layer. Even if the adhesive layer is deteriorated and the adhesive force is reduced, the metal foreign object can be captured in the low electric field portion.

It is a perspective view which shows the gas insulated electric apparatus by Embodiment 1 of this invention. It is an expansion front fragmentary sectional view which shows the bottom part of a gas insulated electrical apparatus. It is a diagram which shows the relationship between a tank bottom surface electric field and the maximum flying height. It is a diagram which shows the relationship between the length of a foreign material, and a floating electric field. It is a diagram which shows the relationship between the shape factor of a metal plate recessed part, and the electric field of a recessed part bottom part. It is sectional drawing which shows the shape of a metal plate recessed part. It is sectional drawing which shows the metal plate recessed part shape, its electric field distribution, and the state in which the foreign material entered. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 2 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 3 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 3 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 4 of this invention. It is a perspective view which shows the gas insulated electric apparatus by Embodiment 5 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 5 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 5 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 5 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 5 of this invention. It is an expansion front fragmentary sectional view which shows the gas insulated electric apparatus by Embodiment 6 of this invention. It is a perspective view which shows the gas insulated electric apparatus by Embodiment 7 of this invention. It is a perspective view which shows the gas insulated electric apparatus by Embodiment 8 of this invention.

Embodiment 1 FIG.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view showing a gas-insulated electric apparatus according to Embodiment 1 of the present invention, and shows a state in which a part of a ground tank is cut out in cross section. FIG. 2 is an enlarged front partial sectional view showing the bottom of the gas-insulated electric apparatus shown in FIG. 1, and shows a metal foreign substance capturing structure.

  In the figure, in the gas-insulated electrical apparatus 1 according to the present invention, a cylindrical ground tank 3 is filled with an insulating gas, and a high-voltage conductor 2 is disposed along the central axis of the ground tank 3. The high voltage conductor 2 is supported on the ground tank 3 by an insulating spacer (not shown) made of an insulating member.

  As the insulating gas filled in the ground tank 3, SF6, dry air, nitrogen, carbon dioxide and the like are used. In order to enhance the insulating performance of the insulating gas and to make the entire gas-insulated electric device 1 compact. In general, the pressure of the insulating gas is set higher than the atmospheric pressure, and the gas is sealed in the ground tank 3.

  A foreign matter capturing structure 4 is installed on the bottom surface of the ground tank 3, and the foreign matter capturing structure 4 is electrically connected to the ground tank 3 by being fixed to the ground tank 3 by welding or bolting. The foreign matter capturing structure 4 includes a plurality of concave and convex metal plates 5 and adhesive layers 6a and 6b installed only in low electric field portions formed in the concave portions 5a, 5b and 5c of the metal plate 5. 6c, and at least the surfaces of the convex portions 5e to 5h of the metal plate 5 are formed to be smooth curved surfaces. Note that FIG. 2 shows an example in which the metal plate 5 is formed so as to have a smooth waveform, but it is not necessary that all of the metal plates 5 have a smooth shape as long as the concave and convex portions are alternately arranged. .

  Here, the width of the concave portion of the metal plate 5 is d (mm) and the depth is h (mm). In addition, the length of the maximum foreign matter for capturing which is not shown is L (mm). In the metal plate 5, when the shape factor α = (h−L) / d is defined as one of the measures for defining the shape of the recess, in the present embodiment, the shape factor α of the metal plate 5 is L = 3 mm. The metal plate 5 is formed so that α ≧ 0.8 and α ≧ 1.0 when L = 6 mm. The reason for setting α ≧ 0.8 or α ≧ 1.0 will be described later.

  Next, the operation of the foreign substance capturing structure 4 will be described. When a voltage is applied to the high voltage conductor 2, the electric field on the inner surface of the ground tank 3 increases. At this time, if a metal foreign object is mixed in the ground tank 3, the metal foreign object is charged by the action of an electric field, and receives an electrostatic force in the direction of rising from the inner surface of the ground tank 3. When the electrostatic force becomes larger than the gravity due to the weight of the metal foreign object, the metal foreign object rises and starts moving toward the high voltage conductor 2.

  In general, since the electric field in the high voltage conductor 2 is higher than the electric field in the bottom surface of the ground tank 3, if a metal foreign object approaches or contacts the high voltage conductor 2, the withstand voltage performance of the high voltage conductor 2 decreases. become. When the shape of the metal foreign object is linear, the electric field concentrates on the tip thereof, and therefore the shape of the metal foreign object that has the greatest influence on the withstand voltage performance is when it is linear. Even if such a linear metallic foreign matter does not generate a sufficiently large electrostatic force to rise toward the high voltage conductor 2, for example, if the linear metallic foreign matter stands up due to mechanical vibration or the like, the electrostatic force Due to this, the standing state may continue. And when a linear metal foreign material stands up, the electric field of the metal foreign material tip will become large locally, and withstand voltage performance will fall.

  On the other hand, in the foreign matter capturing structure 4 according to the present invention, the adhesive layers 6a, 6b, and 6c are provided only in the low electric field portions of the concave portions 5a, 5b, and 5c of the metal plate 5, and the metallic foreign matter is When entering the low electric field part of the recesses 5a, 5b, and 5c, it is captured by the adhesive layers 6a, 6b, and 6c, so that it does not rebound and rise again. The strength of the electric field in the recesses 5a, 5b, and 5c is smaller than the strength of the electric field on the other bottom surface of the ground tank 3 where the foreign substance capturing structure 4 is not installed. It is difficult for the metal foreign matter that has entered to be subjected to electrostatic force that causes the surface to rise again.

  The strength of the electric field of the recesses 5a, 5b, and 5c is adjusted by adjusting the width and depth of the recesses 5a, 5b, and 5c, thereby increasing the electric field strength of the other bottom surface of the ground tank 3 where the foreign substance capturing structure 4 is not installed. It is possible to make it a fraction of 1 to 1/10 or less.

  In order to exert the effect of the foreign substance capturing structure 4 as described above, what is necessary is to perform so-called pre-application in which the voltage applied to the high-voltage conductor 2 is gradually increased before the gas-insulated electric apparatus 1 is operated. By doing so, the metallic foreign matter is gradually guided to the low electric field portion created by the foreign matter capturing structure 4 installed below the ground tank 3 while repeatedly floating and dropping by electrostatic force. In addition, by applying mechanical vibration, the metal foreign object can be moved downward by the gravity of the metal foreign object itself.

  Next, the reason why the shape factor α is set so that α ≧ 0.8 or α ≧ 1.0 will be described. The electric field on the bottom surface of the tank 3 needs to be designed so that the metal foreign object does not float due to electrostatic force during operation of the gas-insulated electrical apparatus 1. For example, the relationship between the electric field on the bottom surface of the tank and the floating of the metal foreign object and the relationship with the arrival of the high voltage conductor 2 is as shown in FIG.

  FIG. 3 shows the relationship between the tank bottom surface electric field (kVrms / mm) and the maximum flying height (mm) in the case of an aluminum wire having a metal foreign object length of 3 mm and a diameter of 0.2 mm. While the case where the inner wall is composed only of metal is shown, the dotted line shows the case where the tank inner wall is coated with a phthalic acid resin.

  In the figure, when the tank inner wall is formed only of metal, the tank bottom surface electric field is 0.4 kVrms / mm and the metal foreign matter has already floated, and reaches the high voltage conductor 2 at 1.0 kVrms / mm. On the other hand, when the inner wall of the tank is coated with a phthalic acid resin, the metal foreign matter floats at 0.7 kVrms / mm and reaches the high voltage conductor 2 at 1.3 kVrms / mm.

  As described above, assuming an aluminum wire foreign material having a length of 3 mm, the upper limit of the tank design electric field when the tank inner wall is made of metal only or coated with a phthalic acid resin is approximately 1 kVrms / mm. If it exceeds, the aluminum wire foreign matter may reach the high voltage conductor 2 to cause a dielectric breakdown.

  In addition, when an aluminum wire foreign matter longer than 3 mm is mixed, the aluminum wire foreign matter may reach the high voltage conductor 2 even in an electric field of 1 kVrms / mm or less, thereby causing a dielectric breakdown. Assuming a maximum size of 3 mm as the size of the metallic foreign matter that may be mixed into the tank, the upper limit of the tank design electric field is approximately 1 kVrms / mm as described above.

On the other hand, the electric field E for raising the linear metal foreign object upright on the metal surface can be theoretically calculated by the following equation (1) when the shape of the metal foreign object is assumed to be a half-spheroid. I can do it.
Floating electric field E = {ln (2L / r) -1} [2ρr ² g / (3ε ₀ L {ln (L / r) −0.5})] ^0.5 ... (1)
Here, r, L, and ρ are the radius, length, and density of the metal foreign object, g is the gravitational acceleration, and ε ₀ is the dielectric constant of vacuum. FIG. 4 is a diagram showing the relationship between the length L of the foreign matter and the floating electric field E for an aluminum linear foreign matter having a radius r of 0.2 mm based on the formula (1).

  The theoretical levitating electric field E of a metallic foreign object having a length L of 3 mm is about 0.1 kVrms / mm, and about 0.08 kVrms / mm in the case of a length of 6 mm, and the levitating electric field E increases as the length of the metallic foreign object increases. Will decline. Therefore, in order to reliably capture the metallic foreign matter with the foreign matter capturing structure 4, for example, when the maximum length of the metallic foreign matter existing in the tank 3 is 3 mm, it is 0.1 kVrms / mm or less, and when it is 6 mm, 0.08 kVrms / mm. It is necessary to set the shape and dimensions of the metal plate 5 so that a metal foreign object enters a region of mm or less.

  Next, the electric field distribution in the recesses 5a, 5b, and 5c of the metal plate 5 will be described. The curve (a) in FIG. 5 shows the case where β = h / d is defined as the shape factor β of the metal plate 5 when the foreign matter capturing structure 4 is installed on the bottom surface where the electric field at the bottom surface of the tank 3 is 1 kVrms / mm. It is a diagram which shows the result of having calculated | required the relationship between (beta) and the electric field of the recessed part bottom part of the metal plate 5 by the electric field analysis.

  Based on the characteristics of the electric field distribution of the metal plate recess, the shape that the metal plate recess should have will be described. For example, when the length of the maximum foreign material is 3 mm, as shown in FIG. 4, the electric field at the bottom of the metal plate recess needs to be 0.1 kVrms / mm or less. Here, the depth of the recess is assumed to be h1, Considering the metal plate 5 having a width d and a bottom surface electric field of 0.1 kVrms / mm, the shape factor β1 is β1 = h1 / d = 0.8, as shown in FIG. It is determined.

  However, the metal foreign object itself has a maximum length of 3 mm, and when the entire metal foreign object enters the region of 0.1 kVrms / mm or less, which is a theoretical levitating electric field, the levitating force of the metal foreign object due to electrostatic force is obtained. Can be weakened sufficiently. Accordingly, h ≧ h1 + 3 (mm) is required as the depth h of the recess in consideration of the length of 3 mm of the metal foreign matter. In other words, since h1 ≦ h−3, h1 = 0.8d obtained by modifying h1 / d = 0.8 is substituted into this equation and rearranged, and again defined as the shape factor α, α = (h−3) / d It is expressed as ≧ 0.8.

  FIG. 7 shows the shape of the concave portion of the metal plate 5 satisfying this condition, the electric field distribution thereof, and the state in which the metal foreign matter X enters. Similarly, when the maximum length of the metal foreign object is 6 mm, as shown in FIG. 4, it is necessary to make 0.08 kVrms / mm or less over the entire metal foreign object, so that 0.08 kVrms / mm as shown in FIG. In order to make it equal to or less than mm, the shape factor β needs to be 1.0 or more, and the shape factor α = (h−6) /d≧1.0 needs to be calculated in the same manner as in the case of 3 mm. There is.

  After that, when either the depth h or the width d of the recess is determined, the other dimension required is automatically determined. Even if the maximum length of the metallic foreign object is other than the above, the necessary shape factor can be obtained by the same method. Practically, the maximum value of the size of the metallic foreign matter mixed in the tank 3 is about 3 to 6 mm as described here, and the larger metallic foreign matter is removed in the manufacturing process. In order not to affect the performance of the apparatus, the shape factor α is, for example, α = (h−L) /d≧0.8 when L = 3 mm, and α = (h−L) when L = 6 mm. ) /D≧1.0 is generally sufficient.

  In terms of electrostatic force, for example, a linear metal foreign object in a standing state has a larger electrostatic force than other metal foreign objects such as spheres. Since aluminum is the lightest metal foreign substance that can be mixed in, if a linear aluminum metal foreign object is taken into consideration, there is an effective foreign substance capturing structure for almost all other metal foreign substances. Can be configured.

  As described above, by defining the shape factor α of the concave portion of the metal plate 5 in accordance with the size of the metal foreign matter mixed in the tank 3, the electrostatic force acting on the metal foreign matter having the targeted size can be sufficiently reduced. Therefore, the metal foreign object can be reliably captured only by the electric field reduction effect due to the recess.

  In order to reliably capture the metal foreign matter only by the electric field reducing effect of the concave portion, as described above, the concave portion is satisfied so as to satisfy the shape factor α according to the maximum length of the metallic foreign matter to be captured. It is necessary that the entire metal foreign object is located at a position below the theoretical levitating electric field, but the entire metal foreign object is not necessarily located at a position below the theoretical levitating electric field. It can also be good.

  That is, even if only the vicinity of the bottom of the recess is less than or equal to the theoretical levitation electric field, the metal foreign matter can be reliably captured by providing the adhesive layers 6a to 6c. That is, in this case, only the electric field at the bottom of the recess should be 0.1 kVrms / mm or less. For example, if the length of the metal foreign matter is 3 mm, the recess is set so that β = h / d ≧ 0.8. It is not necessary to form the recess so that α = (h−3) /d≧0.8.

  As described above, the shape factor of the concave portion of the metal plate 5 is configured such that, for example, if the length of the metal foreign matter is 3 mm, β = h / d ≧ 0.8, and the length of the metal foreign matter is If it is 6 mm, it is configured such that β = h / d ≧ 1.0, and by further installing the adhesive layers 6a to 6c, the electrostatic force generated in the metal foreign matter is sufficiently reduced, and further the metal foreign matter is removed. A foreign matter capturing structure that can be reliably captured can be configured.

  In the above, the case where the shape of the concave portion is determined in consideration of the electric field on the bottom surface of the tank 3 and the length of the metal foreign matter has been described. However, in the following, the processing efficiency of the metal plate and the ability to capture the metal foreign matter are referred to. How to determine the shape of the recess from the viewpoint will be described. Curve (b) in FIG. 5 shows a convex portion of the metal plate 5 when a metal plate concave portion having a shape factor β = 3 as shown in FIG. 6 is installed on the bottom surface of the tank 3 where the electric field on the bottom surface of the tank is 1 kVrms / mm. It is the diagram which showed the relationship between (gamma) = hi / d and the electric field in depth hi, when the depth of the recessed part from a top part is set to hi. As shown in FIG. 5, in the region where the electric field is 0.1 kVrms / mm or less, that is, in the region where the shape factor β ≧ 0.8, the curves (a) and (b) almost overlap. That is, in the region where the electric field is 0.1 kVrms / mm or less, the electric field at an arbitrary depth hi of the concave portion of the metal plate 5 as shown in FIG. 6 has a width of d and a depth h of hi. It can be seen that the electric field at the bottom of the concave portion of the metal plate 5 formed in is substantially the same.

  That is, if the electric field at the bottom of the concave portion is set to 0.1 kVrms / mm or less, a metal plate formed so as to satisfy β = 0.8 will be described, for example, in the example of FIG. Even if the metal plate 5 formed so as to be formed is provided, it can be similarly reduced to 0.1 kVrms / mm or less. Therefore, it can be said that forming the metal plate 5 so as to satisfy β = 0.8 can reduce the size of the metal plate 5 itself, facilitate processing, and be efficient. Further, as shown in FIG. 5, when the foreign matter capturing structure 4 according to the present invention is not provided, the electric field at the bottom surface of the tank 3 is 1 kVrms / mm, whereas the foreign matter capturing structure 4 is provided and β = 0.8. When designed, the electric field at the bottom of the recess is 0.1 kVrms / mm, and the electric field is 1/10, and a large electric field reduction effect can be obtained efficiently. In the above description, the electric field at the bottom surface of the tank 3 is 1 kVrms / mm, but the electric field at the bottom of the recess is considerably lower than the electric field at the bottom surface of the tank 3 even if the electric field at the bottom surface of the tank 3 is other values. Thus, it is possible to capture the metal foreign matter. As described above, regardless of the electric field on the bottom surface of the tank 3, if it is configured so that β ≧ 0.8, the metal foreign matter can be reliably captured. Further, as described above, when the length L of the metal foreign matter is taken into consideration, the recess may be formed so that α ≧ 0.8.

  Next, the reason why the adhesive layers 6a to 6c are provided only in the low electric field portion and the effect thereof will be described while forming the concave portions 5a to 5c by the metal plate 5 to constitute the low electric field portion structure. The gas-insulated electrical apparatus 1 assembled at the factory is subjected to a withstand voltage test in order to confirm the quality of insulation. At this time, if a test voltage is applied in a state where metal foreign matter is mixed in the tank 3, the metal foreign matter floats and reaches the high-voltage conductor 2 as described above, and the withstand voltage performance may be reduced.

  Therefore, before applying the test voltage, so-called pre-application that gradually increases the applied voltage to the high-voltage conductor 2 is performed. By doing so, the metallic foreign matter is gradually guided to the low electric field portion created by the foreign matter capturing structure 4 installed below the ground tank 3 while repeatedly rising and falling by electrostatic force, and the electrostatic force is reduced. Further, the foreign metal is reliably captured by the capturing force of the adhesive layers 6a to 6c.

  In addition, by applying mechanical vibration, the metal foreign matter is moved downward by the gravity of the metal foreign matter itself and is captured by the foreign matter capturing structure 4. The metal foreign matter captured by the foreign matter capturing structure 4 remains fixed to the low electric field portion of the foreign matter capturing structure 4 even when a test voltage is applied to the high voltage conductor 2, and the withstand voltage performance is degraded in the withstand voltage test. Absent. The gas-insulated electrical apparatus 1 that has been subjected to a series of tests including a withstand voltage test is transported on land or sea and installed on-site.

  Operation is started after confirming that there is no problem in performance by conducting a withstand voltage test or the like at the site. Here, when the metallic foreign matter is captured only by the electrostatic force reduction effect by providing the low electric field portion without providing the adhesive layers 6a to 6c in the foreign matter capturing structure 4, due to vibration or tilt during transportation, or due to natural disasters, etc. There is a possibility that the metal foreign matter captured by the pre-application during the test at the factory may move out of the foreign matter capturing structure 4.

  Therefore, it is necessary to pre-apply again after installation at the site and capture the metal foreign matter in the foreign matter capturing structure 4 again. On the other hand, if the adhesive layers 6a to 6c are provided in the low electric field part, the metal foreign matter is surely captured without moving out of the foreign matter capturing structure 4 between the shipment from the factory and the installation at the site. Therefore, the pre-application work at the site can be omitted or simplified.

  On the other hand, when the metal foreign matter is captured only by the adhesive layer provided on the bottom surface of the ground tank 3, the metal foreign matter is moved to a place where the adhesive layer is not installed during transportation from factory shipment to field installation. However, if the adhesive layer is deteriorated and the adhesive force is reduced while the gas-insulated electrical apparatus 1 is operated for a long period of time, the metal foreign matter may float due to electrostatic force. Furthermore, for example, if a linear metal foreign object is captured in the adhesive layer in an upright state, the electric field at the tip of the linear metal foreign object increases, so that the withstand voltage performance decreases during the withstand voltage test, or during operation Partial discharge may occur, and long-term insulation reliability may decrease.

  On the other hand, in the foreign matter capturing structure 4 in which the concave portions 5a to 5c are formed so that the floating of the metallic foreign matter can be suppressed only by the electrostatic force reduction effect by the low electric field as in the present embodiment, the concave portions 5a to 5c are further provided. By providing the adhesive layers 6a to 6c only in the low electric field part, even if the adhesive strength of the adhesive layers 6a to 6c is decreased or lost due to aging during operation or for some reason, the metal foreign matter is low. Since it can be surely captured by the electric field part, it does not rise again and deteriorates the insulation performance.

  Further, by forming the recesses 5a to 5c in consideration of the shape factor α as in the present embodiment, even if the linear metal foreign object is fixed to the adhesive layers 6a to 6c while standing upright, the recess in the foreign object capturing structure 4 Since 5a to 5c have a sufficiently low electric field, it is possible to suppress the concentration of the electric field at the tip of the metal foreign object, and it is possible to prevent the withstand voltage performance from being reduced and the partial discharge from occurring.

  As described above, the recesses 5a to 5c considering the shape factor α as in the present embodiment are installed at the bottom of the ground tank 3 of the gas-insulated electrical apparatus 1, and the low electric field portions of the recesses 5a to 5c are provided. By providing only the pressure-sensitive adhesive layers 6a to 6c, it is possible to provide the gas-insulated electric device 1 with much higher insulation reliability as compared with the case where only the concave portion is provided or the case where only the pressure-sensitive adhesive layer is provided.

  In the above description, the case where the metal plate 5 is used to form the recesses 5a to 5c serving as the low electric field portions has been described. However, other methods may be used for forming the recesses, for example, Embodiment 4 described later. As shown, the tank 3 itself may be provided with a recess that satisfies the shape factor α.

Embodiment 2. FIG.
FIG. 8 is an enlarged cross-sectional front view showing a gas insulated electric device according to Embodiment 2 of the present invention. In the present embodiment, the adhesive layers 8b, 8c, 8d are installed in the concave portions of the metal plate 7 formed into a shape in which a plurality of concave portions and convex portions are alternately arranged, and the convex portions 7a at both ends of the metal plate 7 are further provided. Adhesive layers 8a and 8e are installed on the inner surface of the ground tank 3 located below 7b.

  By configuring as described above, the metal foreign matter moved while repeatedly flying and dropping due to pre-application to the high voltage conductor 2 (not shown) is captured by the adhesive layers 8b, 8c and 8d of the low electric field portion in the recess, The metal foreign matter that has entered both ends of the metal plate 7 so as to slide down the inner surface of the ground tank 3 is captured by the adhesive layers 8a and 8e located below the both ends.

  Therefore, it is possible to capture the metal foreign matter by sliding the metal foreign matter along the inner surface of the ground tank 3 by applying an external mechanical vibration such as hitting with a hammer in addition to the pre-application, and the adhesive layer 8a. Since the electric field at the position where 8e is installed is sufficiently low, it is possible to reliably capture the metal foreign object while suppressing the re-floating of the metal foreign object due to the decrease in adhesive force and the occurrence of partial discharge at the metal foreign object tip. Therefore, it is possible to provide a gas-insulated electric device with high insulation reliability.

Embodiment 3 FIG.
FIG. 9 is an enlarged cross-sectional front view showing a gas insulated electric device according to Embodiment 3 of the present invention. In the present embodiment, the insulating layers 9a, 9b, 9c, 9d are provided on the convex portions of the metal plate 7 formed into a shape in which a plurality of concave portions and convex portions are alternately arranged, and the adhesive layers 8b, 8c, 8d is provided, and adhesive layers 8a and 8e are further provided on the inner surface of the ground tank 3 positioned below the convex portions at both ends of the metal plate 7.

  By configuring as described above, when the metal foreign matter that has moved while repeating the floating and dropping by pre-application to the high voltage conductor 2 (not shown) falls on the convex portion of the metal plate 7, the insulating layer is formed on the convex portion. Since it is provided, the movement of charges from the metal plate 7 is limited. This suppresses the charging of the metal foreign object and suppresses the electrostatic force of the metal foreign object. Therefore, the flying height when the metal foreign object falls on the convex portion and jumps up is suppressed, and the metal foreign object becomes the high-voltage conductor 2. Can be prevented from reaching. Therefore, it is possible to prevent a decrease in withstand voltage performance caused by the foreign metal reaching the high voltage conductor 2 during pre-application, and to provide a gas insulated electric device with high insulation reliability.

  In FIG. 9, the case where the insulating layers 9a, 9b, 9c, and 9d are provided only on the convex portions has been described. However, as shown in FIG. 10, the insulating layer 10 is applied to the entire upper surface of the metal plate 7, and the adhesive layer 8b. , 8c, 8d may be provided on the insulating layer 10.

Embodiment 4 FIG.
FIG. 11 is an enlarged sectional front view showing a gas insulated electric device according to Embodiment 4 of the present invention. In the present embodiment, a recess 11 is provided at the bottom of the ground tank 3, and an adhesive layer 12 is provided at the bottom of the recess 11. The recess 11 is configured to be a groove formed in the same direction as the central axis of the high-voltage conductor 2 of the gas-insulated electric apparatus 1, and the width d and the depth h thereof are described in the first embodiment. It is set based on the shape factors α and β.

  By configuring as described above, the metal foreign matter moved while repeatedly flying and dropping due to pre-application to the high voltage conductor 2 (not shown) is captured by the adhesive layer 12 provided at the bottom of the recess 11 and grounded. The metal foreign matter that slides down the inner surface of the tank 3 also falls into the recess 11 and is captured by the adhesive layer 12.

  Therefore, it is possible to capture the metallic foreign matter by sliding the metallic foreign matter along the inner surface of the ground tank 3 by applying an external mechanical vibration such as hitting with a hammer in addition to the pre-application. Since the electric field at the position where the layer 12 is installed is sufficiently low, the metallic foreign matter can be reliably captured while suppressing the re-floating of the metallic foreign matter due to the decrease in adhesive force and the partial discharge at the tip of the metallic foreign matter. A highly reliable gas-insulated electric device can be provided.

  In addition, in FIG. 11, although the case where it comprised so that it might become the groove | channel shape formed in the same direction as the central axis of the high voltage conductor 2 as a shape of the hollow part 11 was demonstrated, the said conditions of shape factors (alpha) and (beta) are mentioned. If satisfying, the shape of the opening of the depression 11 (the shape seen from above in FIG. 11) is, for example, a circle having a diameter d, a square having a dimension of one side d, and a direction intersecting the central axis of the high-voltage conductor 2. Even in the case of the formed groove or the like, the same effects as described above are obtained.

Embodiment 5 FIG.
FIG. 12 is a perspective view showing a gas-insulated electric apparatus according to Embodiment 5 of the present invention, and shows a state in which a part of the ground tank is cut out in cross section. FIG. 13 is an enlarged front partial cross-sectional view showing the gas insulated electric device shown in FIG.

  In the figure, metal round bars 13 a, 13 b, 13 c, 13 d, and 13 e are arranged at predetermined intervals on the bottom surface of the ground tank 3 in the same direction as the central axis of the high voltage conductor 2 and are electrically connected to the ground tank 3. It is connected. Adhesive layers 14b, 14c, 14d, and 14e are installed at the bottoms of the recesses formed between the metal round bars 13a, 13b, 13c, 13d, and 13e, and outside the metal round bars 13a and 13e at both ends. Adhesive layers 14a and 14f are installed.

  Here, the diameter and installation interval of the metal round bars 13a, 13b, 13c, 13d, and 13e are set such that the diameter is h and the installation interval is d as shown in FIG. The shape factors α and β are set as shown in the first embodiment. The reason why the metal round bar is used instead of the metal square bar is that when the square bar is used, the electric field may concentrate on the corner.

  By configuring as described above, the metal foreign matter that has moved while repeating floating and dropping due to pre-application to the high-voltage conductor 2 is provided in the recess formed between the metal round bars 13a, 13b, 13c, 13d, and 13e. Further, the metal foreign matter that slides down on the inner surface of the ground tank 3 is captured by the adhesive layers 14a and 14f while being captured by the adhesive layers 14b, 14c, 14d, and 14e.

  Therefore, it is possible to capture the metallic foreign matter by sliding the metallic foreign matter along the inner surface of the ground tank 3 by applying an external mechanical vibration such as hitting with a hammer in addition to the pre-application. Since the electric field at the position where the layers 14b, 14c, 14d and 14e are installed is sufficiently low, and the electric field at the position where the adhesive layers 14a and 14f are installed is also relatively low, metal due to a decrease in adhesive force It is possible to provide a gas-insulated electrical device with high insulation reliability capable of reliably capturing a metal foreign object while suppressing the re-floating of the foreign object and the occurrence of partial discharge at the tip of the metal foreign object.

  Further, as shown in FIG. 14, the adhesive layer 15 is installed over a part of the inner surface of the ground tank 3, and the metal round bars 13 a, 13 b, 13 c, 13 d, and 13 e are placed on the adhesive layer 15. Anyway. Further, as shown in FIG. 15, insulating layers 16a, 16b, 16c, 16d, and 16e may be provided on the upper surfaces of the metal round bars 13a, 13b, 13c, 13d, and 13e. With this configuration, the electrostatic force of the metal foreign object is restricted by restricting the movement of the electric charge from the metal round bar 13a, 13b, 13c, 13d, 13e to the metal foreign object falling on the metal round bar 13a, 13b, 13c, 13d, 13e. Therefore, the flying height when the metallic foreign object jumps up can be suppressed. Therefore, it is possible to prevent the insulation performance from being lowered during pre-application.

Further, as shown in FIG. 16, the metal bars 17a to 17e formed so that the surface facing the high voltage conductor 2 is a smooth curved surface, and between the metal bars 17a to 17e and between the metal bars 17a and 17e. Adhesive layers 18a to 18f may be provided on the outer side. In this way, if the surface facing the high voltage conductor 2 is a smooth curved surface, it is possible to suppress the concentration of the electric field on the metal rod, and therefore the metal rod does not necessarily have a circular cross section.
13 to 16, the case where the metal round bar or the metal bar is arranged in the same direction as the central axis of the high voltage conductor 2 has been described. However, the direction intersecting the central axis, that is, the ground tank You may arrange | position along 3 inner circumferences.

Embodiment 6 FIG.
FIG. 17 is an enlarged front partial sectional view showing a gas insulated electric device according to Embodiment 6 of the present invention. In the figure, the metal support members 19a, 19b, 19c formed so that the upper surface facing the high voltage conductor 2 has a smooth curved surface have a predetermined height h from the bottom surface of the ground tank 3. While being fixed by 20a, 20b, 20c, it is electrically connected to the ground tank 3.

  An adhesive layer 21 is provided on the inner surface of the ground tank 3 located below the metal plates 19a, 19b, 19c. Here, the height of the metal plates 19a, 19b, and 19c from the bottom surface of the ground tank 3 is h, and the interval between the end portions of the metal plates 19a, 19b, and 19c is d, and the metal plates 19a, 19b, The shape factors α and β of the recess formed by 19c and the inner surface of the tank 3 are set to the same values as those shown in the first embodiment.

  By configuring as described above, the metal foreign matter that has moved while repeating floating and dropping due to pre-application to the high-voltage conductor 2 is disposed on the bottom surface of the recess formed by the metal plates 19a, 19b, and 19c. In addition to being captured by 21, metal foreign objects that slide down the inner surface of the ground tank 3 are also captured by the adhesive layer 21.

  Therefore, it is possible to capture the metallic foreign matter by sliding the metallic foreign matter along the inner surface of the ground tank 3 by applying an external mechanical vibration such as hitting with a hammer in addition to the pre-application, and the adhesive layer 21. Since the electric field at the position where the is installed is sufficiently low, the metal foreign matter is reliably captured while suppressing the re-floating of the metal foreign matter due to the decrease in adhesive force and the occurrence of partial discharge at the tip of the metallic foreign matter. Therefore, a gas insulated electric device with high insulation reliability can be provided.

  In addition, by providing an insulating layer on the upper surface of the metal plates 19a, 19b, and 19c, the jumping height of the metal foreign matter dropped on the metal plates 19a, 19b, and 19c is suppressed, and the withstand voltage performance degradation during pre-application is reduced. It becomes possible to prevent.

Embodiment 7 FIG.
FIG. 18 is a perspective view showing a gas-insulated electric apparatus according to Embodiment 7 of the present invention, and shows a state where a part of the ground tank is cut out in cross section. In the present embodiment, a foreign substance capturing structure 22 is installed on the bottom surface of the ground tank 3. The foreign matter capturing structure 22 includes a metal plate 23 provided with a slit 24 that is an opening, and an adhesive layer 25 installed on the inner surface of the ground tank 3 positioned below the metal plate 23. The metal plate 23 is installed along the inner surface of the ground tank 3, and the metal plate 23 is fixed to the ground tank 3 by welding or bolting, and both are electrically connected. .

  With the above-described configuration, the metal foreign matter that has moved while repeating flying and dropping due to pre-application to the high voltage conductor 2 falls from the slit 24 and is captured by the adhesive layer 25. Since the place where the adhesive layer 25 is installed is surrounded by the metal plate 23 and the ground tank 3, the electric field is low. Since it is possible to suppress re-levitation or partial discharge from occurring at the tip of the foreign metal, it is possible to provide a gas-insulated electric device with high insulation reliability.

Embodiment 8 FIG.
FIG. 19 is a perspective view showing a gas-insulated electric apparatus according to Embodiment 8 of the present invention, and shows a state in which a part of the ground tank is cut out in cross section. In the present embodiment, the foreign substance capturing structure 26 is installed on the bottom surface of the ground tank 3. The foreign matter capturing structure 26 includes a metal plate 27 provided with a through-hole 28 that is an opening, and an adhesive layer 29 installed on the inner surface of the ground tank 3 positioned below the metal plate 27. The metal plate 27 is installed along the inner surface of the ground tank 3, and the metal plate 27 is fixed to the ground tank 3 by welding or bolting, and both are electrically connected. .

  By configuring as described above, the metal foreign matter that has moved while repeating floating and dropping due to pre-application to the high voltage conductor 2 falls from the through hole 28 and is captured by the adhesive layer 29. Since the place where the adhesive layer 29 is installed is surrounded by the metal plate 27 and the ground tank 3, the electric field is low. Since it is possible to suppress re-levitation or partial discharge from occurring at the tip of the foreign metal, it is possible to provide a gas-insulated electric device with high insulation reliability.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 Gas insulated switchgear, 2 High voltage conductor, 3 Ground tank,
5, 19a-19c metal plate, 5a-5c recess, 6a-6c adhesive layer,
11 hollow part, 12 adhesion layer, 13a-13e metal rod.

Claims (5)

In a gas-insulated electrical apparatus comprising a ground tank filled with an insulating gas and a high-voltage conductor installed in the ground tank via an insulating spacer, a low electric field that prevents metallic foreign objects from floating at the bottom of the ground tank And a pressure-sensitive adhesive layer is provided only in the low electric field portion of the recess. The width of the recess is d, the depth is h, the length of the metal foreign object is L, and α = ( The gas-insulated electric device according to claim 1, wherein the recess is configured such that α is 0.8 or more when h−L) / d. 2. The gas insulated electric device according to claim 1, wherein the recess is formed of a metal plate. The gas-insulated electric device according to claim 1, wherein the concave portion is formed by a hollow portion provided in a bottom portion of the ground tank. 2. The gas insulated electric device according to claim 1, wherein the recess is constituted by a plurality of metal rods installed in the ground tank and an inner wall of the ground tank. The concave portion is composed of a metal plate that is installed at a predetermined height from the bottom of the ground tank and has a smooth curved upper surface, and an inner wall of the ground tank. Item 2. A gas insulated electric device according to Item 1.

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