Electrical equipment and circuit breakers

Abstract

The electrical equipment (40) includes a tank (1) filled with insulating gas, a high-voltage conductor (2) installed inside the tank (1) and to which a DC voltage is applied, and a foreign matter removal device (4) that removes conductive foreign matter (61) inside the tank (1). The foreign matter removal device (4) includes a ring-shaped shield ring (41) with a curved surface on its outer periphery and installed on the high-voltage conductor (2), and a firefly suppression unit (42) that is installed on the outer periphery of the shield ring (41) and prevents the conductive foreign matter (61) from maintaining a firefly state in which it floats around the high-voltage conductor (2).

Description

[Technical field]

[0001] The present disclosure relates to an electrical device and a circuit breaker that include a high-voltage conductor to which a DC voltage is applied, inside a tank filled with insulating gas. [Background technology]

[0002] In electrical equipment that has a high-voltage conductor to which a DC voltage is applied inside a tank filled with insulating gas, a method is used in which a shield ring made of a conductive material is attached to the high-voltage conductor to reduce the electric field in order to prevent corona discharge from the high-voltage conductor.

[0003] If a conductive foreign object gets into the tank and a high DC voltage is applied to the high voltage conductor, the conductive foreign object on the bottom of the tank will float toward the high voltage conductor due to electrostatic force and will be restrained and floating near the high voltage conductor, creating a state called a "fire fly." A conductive foreign object in the fire fly state will be referred to as a "fire fly foreign object" below.

[0004] Since fire-fly particles have the tendency to move toward areas with higher electric fields, when a shield ring is attached to a high-voltage conductor, the fire-fly particles move toward the tip of the shield ring. When the fire-fly particles reach the tip of the shield ring, the electric field relaxation effect of the shield ring is reduced.

[0005] Patent Document 1 discloses a gas-insulated device that provides a different characteristic area in a high-voltage conductor where the electric field is low, so that when a conductive foreign object reaches the different characteristic area, the firefly state can no longer be maintained, causing the firefly foreign object to fall into a foreign object collection area and be captured. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-262144 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the gas-insulated device disclosed in Patent Document 1 has a problem in that the electric field at the location of different characteristics is low, so that firefly contaminants are less likely to gather at the location of different characteristics, and conductive contaminants cannot be efficiently removed.

[0008] The present disclosure has been made in consideration of the above, and has an object to provide an electrical device equipped with a foreign matter removal device that can efficiently remove conductive foreign matter. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the electrical device according to the present disclosure includes a tank filled with an insulating gas, a high-voltage conductor installed inside the tank and to which a DC voltage is applied, and a foreign matter removal device that removes conductive foreign matter from inside the tank. The foreign matter removal device includes a shield ring that is ring-shaped with a curved surface on its outer periphery and is installed on the high-voltage conductor, and a firefly suppression unit that is installed on the outer periphery of the shield ring and prevents the conductive foreign matter from maintaining a firefly state in which it floats around the high-voltage conductor. Effect of the Invention

[0010] According to the present disclosure, it is possible to obtain an electric device equipped with a foreign matter removal device capable of efficiently removing conductive foreign matter. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a configuration of an electrical device according to a first embodiment. [Diagram 2] FIG. 13 is a diagram showing a configuration of an electrical device according to a second embodiment. [Diagram 3] FIG. 13 is an enlarged view of a foreign matter removal device for an electrical device according to a second embodiment; [Figure 4] FIG. 13 is a diagram showing the behavior of conductive foreign matter in the foreign matter removal device for an electrical device according to the second embodiment. [Diagram 5] 11 is an enlarged view of a foreign matter removal device for an electrical device according to a third embodiment. [Figure 6] FIG. 13 is an enlarged view of a foreign matter removal device for an electrical device according to a modified example of the third embodiment. [Figure 7] FIG. 13 is a diagram showing the behavior of conductive foreign matter in a foreign matter removal device for an electric device according to a modified example of the third embodiment. [Figure 8] FIG. 13 is a diagram showing the configuration of a foreign matter removal device for an electrical device according to a fourth embodiment; [Figure 9] FIG. 13 is a diagram showing a closed state of a circuit breaker according to a fifth embodiment. [Figure 10] FIG. 13 is a diagram showing an open state of a circuit breaker according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an electric device and a circuit breaker according to an embodiment will be described in detail with reference to the drawings.

[0013] Embodiment 1 FIG. 1 is a diagram showing the configuration of an electric device according to a first embodiment. The electric device 40 includes a tank 1 filled with an insulating gas, a high-voltage conductor 2 installed inside the tank 1, an insulating spacer 3 supporting the high-voltage conductor 2 inside the tank 1, and a foreign body removal device 4 removing conductive foreign bodies 61 inside the tank 1. The foreign body removal device 4 includes a shield ring 41 installed on the high-voltage conductor 2, a firefly suppression unit 42 that prevents a firefly foreign body from maintaining a firefly state, a low electric field unit 47 provided on the high-voltage conductor 2, and a foreign body capture container 43 formed at the bottom of the tank 1. A high-voltage direct current voltage is applied to the high-voltage conductor 2. The high-voltage conductor 2 has a structure in which the surface of a metal conductor is covered with an insulating coating.

[0014] The shield ring 41 has a curved tip portion that is a high electric field portion. The firefly suppression portion 42 is disposed at the curved tip portion of the shield ring 41. In the foreign matter removal device 4 of the electric device 40 according to the first embodiment, the firefly suppression portion 42 is an insulator made of an insulating material.15 A material having a resistance greater than Ω·m is defined as an insulating material. The outer diameter of the fire-fly suppression portion 42 is the same as that of the shield ring 41. In the first embodiment, the fire-fly suppression portion 42 formed in a disk shape is sandwiched between the shield rings 41 as an example, but the fire-fly suppression portion 42 may be formed in a ring shape and disposed in a recess provided on the outer periphery of the shield ring 41. The low electric field portion 47 is formed by partially thickening the insulating coating covering the metal conductor of the high voltage conductor 2, and the electric field on the surface is lower than that of the other portions of the high voltage conductor 2 other than the low electric field portion 47. In FIG. 1, the low electric field portion 47 is formed below the high voltage conductor 2, but is not limited thereto. The low electric field portion 47 may be formed in a ring shape around the entire circumference of the high voltage conductor 2.

[0015] A conductive foreign object 61 in the tank 1 floats near the surface of the high-voltage conductor 2 and moves toward the high electric field portion where the electric field is higher. When a conductive foreign object 61 on the bottom surface of the tank 1 floats up and becomes a firefly foreign object on the shield ring 41, the firefly foreign object moves toward the high electric field portion at the tip of the shield ring 41 and reaches the firefly suppression portion 42. The firefly foreign object can continue to float by being supplied with electric charge from the high-voltage conductor 2, but since the firefly suppression portion 42 made of an insulating material is sandwiched in the curvature tip portion of the shield ring 41 that is the high electric field portion, the firefly foreign object that reaches the firefly suppression portion 42 loses the electric charge supply from the high-voltage conductor 2 and cannot maintain the firefly state. The conductive foreign object 61 that is no longer in the firefly state falls to the bottom surface of the tank 1 and enters the foreign object capture container 43. Also, when the fire-fly foreign matter reaches the low electric field section 47, the fire-fly foreign matter can no longer maintain the fire-fly state, and the conductive foreign matter 61 that is no longer in the fire-fly state falls to the bottom of the tank 1 and enters the foreign matter capture container 43.

[0016] The foreign object capture container 43 captures the conductive foreign object 61 so that it cannot re-float. By increasing the depth of the foreign object capture container 43, the electric field at the bottom of the foreign object capture container 43 can be made lower than the electric field at the bottom of the tank 1, and the electric field can be made large enough to prevent the conductive foreign object 61 from re-floating. This prevents the conductive foreign object 61 captured in the foreign object capture container 43 from becoming a firefly foreign object again, and ensures that the conductive foreign object 61 is captured reliably.

[0017] The electrical device 40 of embodiment 1 induces firefly foreign matter to the firefly suppression section 42 installed in the high electric field section of the shield ring 41, and cuts off the charge supply from the high voltage conductor 2, thereby making it impossible to maintain the firefly state, thereby making it possible to efficiently capture the conductive foreign matter 61.

[0018] In this embodiment, the firefly suppression portion 42 is made of an insulating material. However, the firefly suppression portion 42 may be made of a semiconductive material. 9 Ω m greater than 10 15 Materials with a resistance of Ω·m or less are considered semiconductive.

[0019] When a firefly foreign object approaches the firefly suppression portion 42 made of an insulating material and the firefly suppression portion 42 becomes charged by the charge of the firefly foreign object, the firefly foreign object may adhere to the surface of the firefly suppression portion 42. If an excessive voltage such as an impulse is applied to the high-voltage conductor 2 with the firefly foreign object attached to the firefly suppression portion 42, insulation breakdown may occur and a corona discharge may occur. If the firefly suppression portion 42 is made of a semiconductive material, the charge of the firefly foreign object flows to the high-voltage conductor 2 via the semiconductive firefly suppression portion 42 and is lost, so that the firefly foreign object does not adhere to the surface of the firefly suppression portion 42.

[0020] Embodiment 2 2 is a diagram showing the configuration of an electric device according to embodiment 2. A foreign matter removal device 4 of an electric device 40 according to embodiment 2 differs from embodiment 1 in that a firefly suppression unit 42 is recessed further than a shield ring 41. In embodiment 2, the distance between the firefly suppression unit 42 and the tank 1 is greater than the distance between the shield ring 41 and the tank 1.

[0021] 3 is an enlarged view of the foreign matter removal device for an electric device according to the second embodiment. Since the distance between the firefly suppression unit 42 and the tank 1 is greater than the distance between the shield ring 41 and the tank 1, the strength of the electric field E2 on the surface of the firefly suppression unit 42 is lower than the strength of the electric field E1 on the surface of the shield ring 41. Since the electrostatic force acting on the conductive foreign matter 61 is the product of the charge stored in the conductive foreign matter 61 and the electric field strength at the location where the conductive foreign matter 61 exists, the electrostatic force acting on the conductive foreign matter 61 at the firefly suppression unit 42 is smaller than the electrostatic force acting on the conductive foreign matter 61 at the shield ring 41.

[0022] 4 is a diagram showing the behavior of a conductive foreign object in the foreign object removal device for an electric device according to the second embodiment. As shown in FIG. 4, the electric field lines EL1 generated on the surface of the shield ring 41 and the electric field lines EL2 generated on the fire-fly suppression unit 42 move in a translational manner so as to almost join together in a space away from the shield ring 41 and the fire-fly suppression unit 42. The fire-fly foreign object moves while jumping along the electric field lines EL1 and EL2. At this time, in the space where the electric field lines EL1 generated on the surface of the shield ring 41 and the electric field lines EL2 generated on the fire-fly suppression unit 42 move in a translational manner, a phenomenon in which the fire-fly foreign object moves from the electric field lines EL1 generated on the surface of the shield ring 41 to the electric field lines EL2 generated on the surface of the fire-fly suppression unit 42 and a phenomenon in which the fire-fly foreign object moves from the electric field lines EL2 generated on the surface of the fire-fly suppression unit 42 to the electric field lines EL1 generated on the surface of the shield ring 41 randomly occur. This creates an opportunity for fire-fly foreign matter that would normally move toward the shield ring 41, which has a higher electric field, to move toward the fire-fly suppression unit 42, which has a lower electric field than the shield ring 41. The fire-fly foreign matter that reaches the fire-fly suppression unit 42 can no longer maintain the fire-fly state. The conductive foreign matter 61 that is no longer in the fire-fly state falls to the bottom of the tank 1 and enters the foreign matter capture container 43.

[0023] In the foreign matter removal device 4 of the electrical device 40 according to the second embodiment, the firefly suppression section 42 may be formed using an antistatic material or a conductive material. 9 A material with a resistance of Ω·m or less is defined as a conductive material. When the fire-fly suppression section 42 is made of an antistatic material, the same effect can be obtained as when the fire-fly suppression section 42 is made of an insulating material. When the fire-fly suppression section 42 is made of a conductive material, the effect of cutting off the supply of electric charge to the fire-fly foreign matter cannot be obtained, but the fire-fly foreign matter can be led to the fire-fly suppression section 42, which has a low electric field, and therefore the fire-fly foreign matter can be efficiently removed.

[0024] Embodiment 3 5 is an enlarged view of a foreign matter removal device for an electric device according to embodiment 3. In the foreign matter removal device 4 for an electric device 40 according to embodiment 3, a gap is provided between a firefly suppression part 42 and a shield ring 41, forming a first groove part 44. The rest is the same as in embodiment 2.

[0025] 5 is a diagram showing the behavior of a conductive foreign object in a foreign object removal device for an electric device according to the third embodiment. As shown in FIG. 5, the electric field lines EL1 generated by the shield ring 41 and the electric field lines EL2 generated by the fire-fly suppression unit 42 move in a translational manner so as to substantially join together in a space away from the shield ring 41 and the fire-fly suppression unit 42. The fire-fly foreign object moves while jumping along the electric field lines EL1 and EL2. At this time, in the space where the electric field lines EL1 generated on the surface of the shield ring 41 and the electric field lines EL2 generated by the fire-fly suppression unit 42 move in a translational manner, a phenomenon in which the fire-fly foreign object moves from the electric field lines EL1 generated on the surface of the shield ring 41 to the electric field lines EL2 generated on the surface of the fire-fly suppression unit 42 and a phenomenon in which the fire-fly foreign object moves from the electric field lines EL2 generated on the surface of the fire-fly suppression unit 42 to the electric field lines EL1 generated on the surface of the shield ring 41 randomly occur. This creates an opportunity for fire-fly foreign matter that would normally move toward the shield ring 41 , where the electric field is high, to move toward the fire-fly suppression portion 42 , where the electric field is lower than that of the shield ring 41 .

[0026] Similarly, the electric field lines EL2 generated in the fire-fly suppression section 42 and the electric field lines EL3 generated in the first groove section 44 move in a translational manner so as to substantially join together in a space away from the fire-fly suppression section 42 and the first groove section 44. For this reason, in a space in which the electric field lines EL2 generated in the fire-fly suppression section 42 and the electric field lines EL3 generated in the first groove section 44 move in a translational manner, a phenomenon in which a fire-fly foreign object moves from the electric field lines EL2 generated on the surface of the fire-fly suppression section 42 to the electric field lines EL3 generated in the first groove section 44, and a phenomenon in which a fire-fly foreign object moves from the electric field lines EL3 generated in the first groove section 44 to the electric field lines EL2 generated on the surface of the fire-fly suppression section 42, occur randomly. As a result, an opportunity is created for a fire-fly foreign object that would normally move toward the fire-fly suppression section 42, which has a high electric field, to move toward the first groove section 44, which has a lower electric field than the fire-fly suppression section 42.

[0027] In a configuration in which the fire-fly suppression portion 42 is recessed further than the shield ring 41, the greater the recession of the fire-fly suppression portion 42, the lower the electric field, and the greater the effect of preventing the fire-fly foreign matter from maintaining the fire-fly state. On the other hand, if the difference between the strength of the electric field generated by the fire-fly suppression portion 42 and the strength of the electric field generated by the shield ring 41 becomes large, the probability that the fire-fly foreign matter is attracted to the stronger electric field generated by the shield ring 41 increases, and the fire-fly foreign matter becomes less likely to reach the fire-fly suppression portion 42. In the foreign matter removal device 4 of the electric device 40 according to the third embodiment, the fire-fly foreign matter is first guided to the fire-fly suppression portion 42, and then the fire-fly foreign matter is guided to the first groove portion 44. Therefore, the foreign matter removal device 4 of the electric device 40 according to the third embodiment can efficiently guide the fire-fly foreign matter to the first groove portion 44, where the electric field is low, and remove the conductive foreign matter 61.

[0028] As with the foreign matter removal device 4 of the electric device 40 according to the second embodiment, the firefly suppression section 42 can also be made of an antistatic material or a conductive material.

[0029] 6 is an enlarged view of a foreign matter removal device for an electric device according to a modification of the third embodiment. In the foreign matter removal device 4 for an electric device 40 according to a modification of the third embodiment, the firefly suppression portion 42 is composed of two ring-shaped insulating materials, and a second groove portion 45 is provided between the firefly suppression portions 42. Since the distance between the firefly suppression portion 42 and the tank 1 is greater than the distance between the shield ring 41 and the tank 1, the intensity of the electric field E3 on the surface of the firefly suppression portion 42 is lower than the intensity of the electric field E1 on the surface of the shield ring 41. In addition, since the distance between the first groove portion 44 and the tank 1 is greater than the distance between the firefly suppression portion 42 and the tank 1, the intensity of the electric field E4 of the first groove portion 44 is lower than the electric field E3 on the surface of the firefly suppression portion 42.

[0030] As described above, the electrostatic force acting on the conductive foreign object 61 is the product of the charge stored in the conductive foreign object 61 and the electric field strength at the location where the conductive foreign object 61 is present, and therefore the electrostatic force acting on the conductive foreign object 61 in the firefly suppression section 42 is smaller than the electrostatic force acting on the conductive foreign object 61 in the shield ring 41. In addition, the electrostatic force acting on the conductive foreign object 61 in the first groove section 44 is smaller than the electrostatic force acting on the conductive foreign object 61 in the firefly suppression section 42.

[0031] 7 is a diagram showing the behavior of conductive foreign matter in a foreign matter removal device for an electric device according to a modification of embodiment 3. In foreign matter removal device 4 for electric device 40 according to a modification of embodiment 3, second groove portion 45 is provided between fire-fly suppression portions 42, which makes it easier for fire-fly foreign matter to reach first groove portion 44 or second groove portion 45, thereby further improving the performance of removing conductive foreign matter 61.

[0032] Embodiment 4 FIG. 8 is a diagram showing the configuration of a foreign matter removal device for an electric device according to a fourth embodiment. In the foreign matter removal device 4 according to the fourth embodiment, a recess is formed on the outer periphery of a shield ring 41, and a firefly suppression section 42 is disposed inside the recess. The firefly suppression section 42 is formed in a ring shape from a positively charged insulating material. An example of the positively charged insulating material is nylon, but other materials may be used. A negative high voltage DC voltage is applied to the high voltage conductor 2. In addition, in the foreign matter removal device 4 according to the fourth embodiment, a low voltage section is not provided on the high voltage conductor 2.

[0033] The fire-fly foreign matter that has become a fire-fly state on the shield ring 41 moves toward the outer periphery where the electric field is stronger. The fire-fly foreign matter that has moved to the outer periphery of the shield ring 41 is negatively charged and is therefore attracted to the fire-fly suppression section 42 which is likely to be positively charged. If the fire-fly foreign matter adheres to the fire-fly suppression section 42, it is captured by the fire-fly suppression section 42 and is unable to maintain the fire-fly state. The captured conductive foreign matter 61 remains attached to the surface of the fire-fly suppression section 42, but since the fire-fly suppression section 42 is disposed inside the recess and the surface of the fire-fly suppression section 42 is recessed below the surface of the shield ring 41, there is no risk of the insulation performance being reduced even if the conductive foreign matter 61 remains attached to the fire-fly suppression section 42.

[0034] Although the above example shows a configuration in which a negative high voltage DC voltage is applied to the high voltage conductor 2, when a positive high voltage DC voltage is applied to the high voltage conductor 2, the same effect as above can be obtained by using the fire-fly suppression portion 42 formed in a ring shape from a negatively charged insulating material. That is, if the fire-fly suppression portion 42 is formed from an insulating material having the property of being charged with an opposite attribute to the high voltage DC voltage applied to the high voltage conductor 2, the fire-fly foreign matter can be attached to the fire-fly suppression portion 42 and captured.

[0035] Embodiment 5. Fig. 9 is a diagram showing a closed state of the circuit breaker according to the fifth embodiment. Fig. 10 is a diagram showing an open state of the circuit breaker according to the fifth embodiment. The circuit breaker 50 includes a cylindrical tank 1, an opening / closing unit 24 having a movable electrode portion 51 and a fixed electrode portion 52, and a movable outer conductor 34 and a fixed outer conductor 36 disposed in a pair of bushings 22 extending above the tank 1. In the circuit breaker 50 according to the fifth embodiment, the tank 1 and the bushings 22 are integrally formed to form a sealed container in which insulating gas is sealed.

[0036] The movable end of the tank 1 is plate-shaped with a hole formed in the center. In the arrangement direction of the movable electrode section 51 and the fixed electrode section 52, the direction from the fixed electrode section 52 toward the movable electrode section 51 is referred to as the "movable side", and the direction from the movable electrode section 51 toward the fixed electrode section 52 is referred to as the "fixed side". In Figures 9 and 10, the movable electrode section 51 and the fixed electrode section 52 are aligned in the left-right direction of the paper, so the right side of the paper is the movable side and the left side is the fixed side.

[0037] The circuit breaker 50 has a cylindrical movable side frame 18 connected to the lower end of the movable side outer conductor 34, and a cylindrical fixed side frame 16 connected to the lower end of the fixed side outer conductor 36. The movable side frame 18 and the fixed side frame 16 are made of a conductive material.

[0038] The movable electrode section 51 includes a cylindrical puffer cylinder 92, a movable shield 93 provided at the end of the fixed side of the puffer cylinder 92, a puffer piston 91 installed in the puffer cylinder 92, a conductor rod 14 having a smaller diameter than the puffer cylinder 92 and fixed to the puffer piston 91, a movable contact 5a fixed to the conductor rod 14, and a nozzle 11 arranged around the movable contact 5a. The conductor rod 14 is connected to an insulating rod 12 connected to a shaft of an operating device (not shown) installed outside the tank 1 to operate the movable contact 5a. The puffer piston 91 surrounds the conductor rod 14 from the outer periphery of the tank 1 to close the gap between the conductor rod 14 and the puffer cylinder 92.

[0039] The fixed end of the movable frame 18 is a cylindrical portion 18a that is inserted into the puffer cylinder 92. The movable frame 18 is formed with a through hole 18b that extends in the axial direction of the cylindrical portion 18a, and at least one point on the inner circumferential surface of the through hole 18b is in contact with the conductor rod 14. Therefore, the movable outer conductor 34 is electrically connected to the movable contactor 5a via the movable frame 18 and the conductor rod 14. The fixed outer conductor 36 is electrically connected to the fixed contactor 5b via the fixed frame 16.

[0040] Between the movable side outer conductor 34 and the fixed side outer conductor 36, a direct current flows through the movable side outer conductor 34, the movable side frame 18, the conductor rod 14, the movable side contactor 5a, the fixed side contactor 5b, the fixed side frame 16, and the fixed side outer conductor 36. Therefore, each of the movable side frame 18, the conductor rod 14, the movable side contactor 5a, the fixed side contactor 5b, and the fixed side frame 16 forms a part of the high-voltage conductor 2 to which a high voltage DC voltage is applied.

[0041] The fixed electrode portion 52 has a fixed contact 5b and a cylindrical fixed shield 15 that surrounds the fixed contact 5b from the outer circumferential direction of the tank 1. The fixed contact 5b and the fixed shield 15 are supported by a fixed frame 16.

[0042] The movable electrode section 51 is installed inside the tank 1 so as to be movable in the axial direction of the tank 1. In the fifth embodiment, a state in which the movable contact 5a and the fixed contact 5b are in contact with each other is called a "closed state", and a state in which the movable contact 5a is separated from the fixed contact 5b is called an "open state". An operation of transitioning from the closed state to the open state is called an "interrupting operation", and an operation of transitioning from the open state to the closed state is called an "closing operation". The circuit breaker 50 switches between an open state and a closed state when the movable electrode section 51 moves and the movable contact 5a comes into contact with the fixed contact 5b, or when the movable contact 5a, which was in contact with the fixed contact 5b, separates from the fixed contact 5b.

[0043] In a closed state where the movable contact 5a and the fixed contact 5b are in contact with each other, the fixed shield 15 and the movable shield 93 are in contact with each other. In an open state where the movable contact 5a is separated from the fixed contact 5b, the movable shield 93 is not in contact with the fixed shield 15.

[0044] The puffer piston 91 has a through hole 91a. Therefore, the puffer chamber 32, which is a space surrounded by the puffer cylinder 92, the puffer piston 91, and the cylindrical portion 18a, is connected to the nozzle 11. During a break operation in which the closed state transitions to an open state, the volume of the puffer chamber 32 decreases, and insulating gas is sprayed from the nozzle 11 toward the fixed contact 5b. That is, during a break operation in which the closed state in which the movable contact 5a contacts the fixed contact 5b transitions to an open state in which the movable contact 5a is separated from the fixed contact 5b, the movable electrode portion 51 blows the insulating gas in the puffer chamber 32, which is a space formed between the puffer cylinder 92, the puffer piston 91, and the cylindrical portion 18a, toward the fixed contact 5b. An arc formed between the movable contact 5a and the fixed contact 5b during a break operation is cooled and extinguished by the insulating gas being blown from the nozzle 11.

[0045] The movable frame 18 is provided with a foreign matter removal device 4a. The foreign matter removal device 4a is composed of a movable shield ring 41a having a hollow structure, a first air hole 42a connecting the internal space of the movable shield ring 41a to the puffer chamber 32, and a second air hole 43a connecting the internal space of the movable shield ring 41a to the external space of the movable shield ring 41a. The puffer chamber 32 is connected to the external space of the movable shield ring 41a through the first air hole 42a, the internal space of the movable shield ring 41a, and the second air hole 43a. In the foreign matter removal device 4a, the first air hole 42a and the second air hole 43a are movable firefly suppression parts that prevent firefly foreign matter from maintaining a firefly state.

[0046] The fixed frame 16 is also provided with a foreign matter removal device 4b. The foreign matter removal device 4b is composed of a hollow fixed shield ring 41b, a third air hole 42b connecting the internal space of the fixed shield ring 41b to the internal space of the tube of the fixed shield 15, and a fourth air hole 43b connecting the internal space of the fixed shield ring 41b to the external space of the fixed shield ring 41b. The internal space of the tube of the fixed shield 15 is connected to the external space of the fixed shield ring 41b through the third air hole 42b, the internal space of the fixed shield ring 41b, and the fourth air hole 43b. In the foreign matter removal device 4b, the third air hole 42b and the fourth air hole 43b are fixed firefly suppression parts that prevent firefly foreign matter from maintaining a firefly state.

[0047] When the volume of the puffer chamber 32 increases during the closing operation to transition from the open state to the closed state, insulating gas is sucked into the space inside the movable shield ring 41a from the outside of the movable shield ring 41a through the second air hole 43a. At this time, firefly foreign matter adhering to the movable shield ring 41a is sucked into the space inside the movable shield ring 41a from the second air hole 43a together with the insulating gas. Because the electric field strength inside the movable shield ring 41a is zero, the firefly foreign matter sucked into the space inside the movable shield ring 41a can no longer maintain the firefly state, and falls into the interior of the movable shield ring 41a and is captured.

[0048] Furthermore, when the volume of the puffer chamber 32 increases during the closing operation, insulating gas is sucked from the outside of the fixed shield ring 41b through the fourth air hole 43b into the space inside the fixed shield ring 41b. At this time, firefly foreign matter adhering to the fixed shield ring 41b is sucked into the space inside the fixed shield ring 41b through the fourth air hole 43b together with the insulating gas. Because the electric field strength is zero inside the shield ring, the firefly foreign matter sucked into the space inside the fixed shield ring 41b can no longer maintain its firefly state, and falls into the interior of the fixed shield ring 41b and is captured.

[0049] When the volume of the puffer chamber 32 decreases during an interruption operation that transitions from a closed state to an open state, the insulating gas in the puffer chamber 32 is sprayed to the outside of the movable shield ring 41a through the first air hole 42a, the space inside the movable shield ring 41a, and the second air hole 43a. At this time, firefly foreign matter adhering to the movable shield ring 41a is blown away by the insulating gas blowing out from the second air hole 43a.

[0050] Furthermore, the insulating gas sprayed from the nozzle 11 toward the fixed contact 5b during the interruption operation flows into the space inside the cylinder of the fixed shield 15 and is sprayed to the outside of the fixed shield ring 41b through the third air hole 42b, the space inside the fixed shield ring 41b, and the fourth air hole 43b. At this time, firefly foreign matter adhering to the fixed shield ring 41b is blown away by the insulating gas blowing out from the fourth air hole 43b.

[0051] The circuit breaker 50 according to the fifth embodiment can efficiently capture and remove firefly foreign matter that has gathered on the surfaces of the movable shield ring 41a and the fixed shield ring 41b, which are in a high electric field, by sucking it into the space inside the movable shield ring 41a and the fixed shield ring 41b. In addition, firefly foreign matter that has not been sucked into the interior of the movable shield ring 41a and the fixed shield ring 41b is blown off from the surfaces of the movable shield ring 41a and the fixed shield ring 41b, which are in a high electric field, thereby making it possible to prevent a deterioration in insulation performance caused by firefly foreign matter adhering to the surfaces of the movable shield ring 41a and the fixed shield ring 41b.

[0052] The configurations shown in the above embodiments are merely examples of the contents, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0053] 1 tank, 2 high voltage conductor, 3 insulating spacer, 4, 4a, 4b foreign object removal device, 5a movable contact, 5b fixed contact, 11 nozzle, 12 insulating rod, 14 conductor rod, 15 fixed shield, 16 fixed frame, 18 movable frame, 18a cylindrical portion, 18b, 91a through hole, 22 bushing, 24 opening / closing portion, 32 puffer chamber, 34 movable outer conductor, 36 fixed outer conductor, 40 electrical equipment, 41 shield ring, 41a movable shield ring, 41b fixed shield ring, 42 firefly suppression portion, 42a first air hole, 42b third air hole, 43 foreign object capture container, 43a second air hole, 43b fourth air hole, 44 first groove portion, 45 second groove portion, 47 low electric field portion, 50 Circuit breaker, 51 movable electrode portion, 52 fixed electrode portion, 61 conductive foreign object, 91 puffer piston, 92 puffer cylinder, 93 movable shield.

Claims

1. A tank into which insulating gas is sealed, A high-voltage conductor installed inside the tank to which a DC voltage is applied, The tank is equipped with a foreign matter removal device that removes conductive foreign matter from inside the tank, The aforementioned foreign matter removal device is A ring-shaped shielding ring with a curved surface on its outer circumference, which is installed on the high-voltage conductor, The shield ring is equipped with a firefly suppression unit installed on its outer circumference, which prevents the conductive foreign matter from maintaining a firefly state in which it floats around the high-voltage conductor. The electrical device is characterized in that the firefly suppression part is a ring-shaped member made of a semiconducting material.

2. The electrical device according to claim 1, characterized in that the firefly suppression portion is arranged to be recessed from the curved surface.

3. The electrical device according to claim 2, characterized in that a first groove is provided between the firefly suppression portion and the shielding ring.

4. The firefly suppression unit comprises multiple such units, Multiple of the aforementioned firefly suppression units are installed at intervals. The electrical device according to claim 3, characterized in that a second groove is formed between the firefly suppression portions.

5. The electrical equipment according to any one of claims 1 to 3, further comprising a foreign object capture container for capturing the conductive foreign object that falls after it can no longer maintain the firefly state.

6. The electrical device according to claim 1, characterized in that the firefly suppression portion has the property of being charged with the opposite polarity to the DC voltage applied to the high-voltage conductor and is arranged recessed from the curved surface.

7. A cylindrical tank into which insulating gas is sealed, The tank has a fixed electrode section having a fixed contact installed inside the tank, and a movable electrode section having a movable contact installed movably inside the tank, wherein the opening / closing section closes when the movable contact comes into contact with the fixed contact and opens when the movable contact moves away from the fixed contact, A movable side frame that supports the movable side electrode portion inside the tank, A fixed side frame that supports the fixed side electrode portion inside the tank, The tank is equipped with a foreign matter removal device that removes conductive foreign matter from inside the tank, Each of the movable frame and the fixed frame is a high-voltage conductor to which a DC voltage is applied. The movable electrode portion includes a buffer chamber whose volume decreases when the opening / closing unit is shut off and increases when the opening / closing unit is closed, and a nozzle that sprays the insulating gas pushed out from the buffer chamber when the opening / closing unit is shut off toward the fixed contact. The fixed electrode portion includes a cylindrical fixed shield that covers the fixed contact from the radially outer side of the tank. The aforementioned foreign matter removal device is It is ring-shaped with a curved surface on its outer circumference, and is a movable side shield ring installed on the movable side frame, It is ring-shaped with a curved surface on its outer circumference, and is a fixed-side shield ring installed on the fixed-side frame, A movable side firefly suppression unit is installed on the outer circumference of the movable side shield ring to prevent the conductive foreign matter from maintaining a firefly state in which it floats around the high-voltage conductor, The device comprises a fixed-side firefly suppression unit installed on the outer circumference of the fixed-side shield ring, which prevents the conductive foreign matter from maintaining the firefly state, A circuit breaker characterized in that the movable shielding ring and the fixed shielding ring are installed on the current path of the current flowing due to the DC voltage.

8. The movable side shield ring and the fixed side shield ring have a hollow structure. The movable side firefly suppression section includes a first air vent connecting the puffer chamber and the internal space of the movable side shield ring, and a second air vent connecting the internal space of the movable side shield ring and the external space of the movable side shield ring. The fixed-side firefly suppression section includes a third ventilation hole connecting the internal space of the fixed-side shield to the internal space of the fixed-side shield ring, and a fourth ventilation hole connecting the internal space of the fixed-side shield ring to the external space of the fixed-side shield ring. During the shut-off operation of the opening / closing section, the insulating gas pushed out from the puffer chamber is injected into the space outside the movable side shield ring through the first air vent, the space inside the movable side shield ring, and the second air vent, and the insulating gas blown out from the nozzle and flowing into the interior of the fixed side shield is injected into the space outside the fixed side shield ring through the third air vent, the space inside the fixed side shield ring, and the fourth air vent. The circuit breaker according to claim 7, characterized in that, when the opening / closing section is closed, the insulating gas in the space outside the movable side shield ring is drawn into the puffer chamber through the second ventilation hole, the space inside the movable side shield ring, and the first ventilation hole, and the insulating gas in the space outside the fixed side shield ring is drawn into the puffer chamber through the fourth ventilation hole, the space inside the fixed side shield ring, the space inside the fixed side shield, and the nozzle.

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