JP4812521B2 - Foreign matter conditioning method - Google Patents

Description

  The present invention relates to a foreign matter conditioning method, and more particularly, to a foreign matter conditioning method applied to the removal of conductive foreign matter in a gas insulating device.

  Gas insulation equipment in the prior art is equipped with a low electric field part such as a particle trap because the insulation characteristics deteriorate if conductive foreign substances such as metal strips are mixed inside the container filled with insulating gas, and the operating voltage The conductive foreign matter that behaves by is captured. Further, in order to enhance the trapping effect, foreign matter conditioning is performed in which a conductive foreign matter is moved by applying a voltage lower than a predetermined voltage stepwise before operation and trapped in a particle trap.

  In the prior art, a groove (particle trap) for capturing conductive foreign matter is provided in the vicinity of the insulating spacer provided inside the container filled with the insulating gas, and the conductive foreign matter moves at the operating voltage in the normal operation state. Has been proposed to prevent deterioration of insulation performance without causing conductive foreign matter to adhere to the insulating spacer (see, for example, Patent Document 1).

  In addition, it has been proposed to perform foreign object conditioning by combining an alternating voltage and a direct current voltage that makes the movement of the conductive foreign substance more active in order to efficiently capture the conductive foreign substance before operation (for example, patents). Reference 2).

  In addition, a gas with low electron adhesion and a gas with high electron adhesion are used separately, and before the pressure test, a gas with low electron adhesion is sealed and corona measurement is performed at a low voltage to detect conductive foreign matter. Has been proposed (see, for example, Patent Document 3).

Japanese Utility Model Publication No. 5-2531 (page 4-5: paragraph [0009], FIG. 1) JP-A-57-106320 JP 2000-59935 A (page 7: paragraph [0087], FIG. 7)

In the conventional trapping method and particle conditioning method using a particle trap, it is assumed that the conductive particle moves freely in the electric field when a voltage lower than the operating voltage is applied. In the case of a device in which the inner surface of the container is covered with a dielectric coating for rust prevention or other purposes, it is difficult for the conductive foreign matter to obtain an electric charge, so that the movement of the conductive foreign matter is difficult and the trapping thereof becomes difficult.
Therefore, when conducting foreign matter conditioning, the conductive foreign matter is forced to stand up by making the container vibrate by applying an external impact to the container, such as hammering, while applying a voltage to facilitate movement. There was a problem that it was necessary.

  The present invention has been made to solve the above-described problems, and seeks to obtain a foreign matter conditioning method capable of easily moving a conductive foreign matter even in a gas-insulated device whose inner surface is covered with an insulation. It is.

  The foreign matter conditioning method according to the present invention includes a container having an inner surface covered with an insulating coating with a dielectric coating, and a conductor that is insulated and supported inside the container, and ensures insulation performance in a steady operation state of the conductor. In order to condition the conductive foreign matter in the container with respect to the gas insulation device in which the insulating gas is sealed in the container, the conductive foreign matter is conditioned in the container with the insulation performance of the insulating gas lowered. It is what you do.

  According to the foreign matter conditioning method of the present invention, the conductive foreign matter can be easily moved even in a gas-insulated device in which the inner surface of the container is covered with insulation.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the configuration of a gas insulating apparatus to which the foreign matter conditioning method of the present invention is applied. FIG. 2 is an explanatory view showing the behavior of the conductive foreign matter when the inner surface of the metal container is not covered with an insulating coating, and a diagram showing the applied state of the electric field. FIG. 3 is an explanatory view showing the behavior of the conductive foreign matter when the inner surface of the metal container is covered with an insulating coating, and a diagram showing the application state of the electric field.

FIG. 1 shows the configuration of a gas insulation device to which the foreign matter conditioning method of the present invention is applied. A conductor 2 is housed inside a metal container 1, and the conductor 2 is insulated and supported by an insulating spacer 3. insulating gas 4, such as SF ₆ is filled inside the 1. In the unlikely event that a conductive foreign matter 5 such as a metal strip is mixed or generated in the metal container 1, a particle trap 6 for capturing the conductive foreign matter 5 is installed. The inner surface of the metal container 1 is provided with an insulating coating with a dielectric coating 7 for the purpose of rust prevention or the like.
The present invention is applied to a gas insulation device such as a gas insulation switchgear in which an inner surface of a metal container 1 is coated with a dielectric coating 7, and a conductive foreign material 5 in such a gas insulation device. In the following description, the inner surface of the metal container 1 is covered with an insulation coating. In the following description, the foreign matter conditioning operation with respect to the gas container is described in comparison with a gas insulating device in which the inner surface of the metal container 1 is not coated with the dielectric coating 7. A description will be given separately for a case where there is no metal case and a case where the inner surface of the metal container 1 is covered with insulation.

FIG. 2A shows the behavior of the conductive foreign material 5 when the inner surface of the metal container 1 is not covered with insulation. [Α] is a state in which the conductive foreign material 5 is initially flattened, [β ] Shows a state in which the voltage applied to the conductor 2 is increased and the conductive foreign material 5 stands up and floats, and [γ] shows a state in which the conductive foreign material 5 once floated continues to jump.
FIG. 2 (b) shows the relative strength of the electric field generated in each of the [α] state, [β] state, and [γ] state in FIG. 2 (a).
In FIG. 2, E is a conductive foreign object 5 near the electric field, E ₀ is the electric field conductive objects 5 in the case where the insulating coating of a dielectric film 7 on the inner surface of the metallic container 1 has not been subjected to standing floats, E ₁ Is the operating electric field corresponding to the operating voltage applied to the conductor 2 in the steady operating state, Q is the amount of charge induced by electrostatic induction in the conductive foreign material 5, Q ₀ and Q ₁ are just before the conductive foreign material 5 is levitated. The amount of charge obtained, Fe is the electrostatic force acting on the conductive foreign matter 5, and Fg is the gravity acting on the conductive foreign matter 5. A is an electric field change curve showing a required electric field under a predetermined gas condition for ensuring an insulating function in a steady operation state.

FIG. 3 (a) is a diagram showing the behavior of conductive foreign matter when the dielectric coating 7 is applied to the inner surface of the metal container 1 and the inner surface of the dielectric coating metal container 1 is insulated, and [α] is In the initial state, the conductive foreign matter is flattened, [β] is a state in which the metal container 1 is vibrated from the outside when a low applied voltage is applied to the conductor 2, and the conductive foreign matter obtains a charge, [γ] is stationary In this state, the conductive foreign matter obtains a charge when the voltage applied to the conductor 2 is further increased.
FIG. 3B shows the relative strength of the electric field generated in each of the [α] state, [β] state, and [γ] state in FIG.
In FIG. 3, E is a conductive foreign object 5 near the electric field, E ₀ is the electric field conductive objects 5 in the case where the insulating coating of a dielectric film 7 on the inner surface of the metallic container 1 has not been subjected to standing floats, E ₁ Is the operating electric field corresponding to the operating voltage applied to the conductor 2 in the steady operating state, Q _a and Q _b are the amount of charge obtained immediately before the conductive foreign material 5 is levitated, Fe is the electrostatic force acting on the conductive foreign material 5, Fg is the gravity acting on the conductive foreign material 5. B is an electric field change curve indicating a required electric field under a predetermined gas condition for ensuring the insulating function of the insulating gas 4 in a steady operation state, and C is a predetermined gas condition with a reduced insulating function of the insulating gas 4 according to the present invention. It is an electric field change curve which shows a required electric field.

Next, the operation will be described. First, when the inner surface of the metal container 1 is not covered with insulation, when a voltage is applied to the conductor 2 and an electric field shown in the electric field change curve A is applied in the [α] state in FIG. A charge Q is induced in the conductive foreign material 5 by electrostatic induction. Assuming that the electric field around the conductive foreign material 5 at this time is E, electrostatic force Fe = QE acts on the conductive foreign material 5 roughly, and when Fe exceeds the gravitational force Fg of the conductive foreign material in FIG. As shown in the [β] state, it stands and rises. Then, the electrically conductive foreign material 5 that has been levitated rises to a certain height according to the charge amount Q ₀ and the alternating electric field E ₀ obtained immediately before the levitating, then falls due to gravity, and collides with the bottom surface of the metal container 1. resulting charge Q ₁ in accordance with the voltage phase when, again floated as shown in [γ] state in FIG. 2 (a). The influence of the conductive foreign material 5 on the insulation performance increases as the length increases. However, when the voltage is further increased to increase the electric field, the shorter conductive foreign material 5 also rises and rises depending on the electric field. The conductive foreign matter 5 having a large size rises and rises, and all the conductive foreign matters 5 that stand up and rise in the operating electric field E ₁ corresponding to the operating voltage applied to the conductor 2 in the normal operation state continue to move.
As described above, the electrically conductive foreign material 5 that has been levitated repeatedly repeats the jumping motion, and moves due to the angle of collision with the bottom surface of the metal container 1 or the distortion of the electric field. When the particle trap 6 is reached, it enters a low electric field portion formed by the particle trap 6 and can no longer obtain an electrostatic force exceeding gravity, and the movement is stopped and captured.

On the other hand, when the inner surface of the metal container 1 is covered with the dielectric coating 7, even if an electric field is applied to the conductive foreign matter on the dielectric coating 7 in the [α] state in FIG. Electric charges are not induced as in the case where the insulating film is not covered with the body coating 7, and even if the electric field E ₀ is raised in the [β] state in FIG. Therefore, when the electric field is further increased and the metal container 1 is vibrated from the outside as shown in the [β] state in FIG. 3A, the electric field at the tip of the conductive foreign material 5 is increased to increase the conductivity. When a partial discharge occurs at the contact point between the foreign matter 5 and the dielectric coating 7 or at the electric field concentration portion at the end of the conductive foreign matter 5, the conductive foreign matter 5 obtains _a charge Qa and floats, and [ The jumping movement is made possible as in the [β] state and the [γ] state.
Also, further increase the electric field in the operating field E ₁ or more, and the contact point between the conductive materials 5 and the dielectric film 7 in the lying state, the partial discharge in the electric field concentration portion of the conductive foreign object 5 end is to occur conductive materials 5 can be erected floating obtain a charge Q _b, becomes [γ] state in FIG. 3 (a), repeated jumping motion as with [γ] states in FIGS. 2 (a) It becomes like this.
However, in order to partially discharge the conductive foreign material 5 as described above, it is necessary to increase the applied voltage and make it higher than the normal operating electric field E ₁ as shown in the electric field change curve B of FIG. is there.

Therefore, in the first embodiment according to the present invention, the insulation performance of the insulating gas 4 is lowered by lowering the pressure of the insulating gas 4 such as SF ₆ enclosed in the metal container 1, so that the portion of the conductive foreign matter 5 is reduced. discharge was easily generated, in operation the electric field E ₁ below as field change curve C in FIG. 3 (b), reducing the insulating performance of the insulating gas 4 to conductive foreign object 5 that fell generates partial discharge Then, the conductive foreign material 5 is in the [γ] state in FIG. 3A, and the conductive foreign material 5 can be moved with the operating electric field E ₁ or less.

In the first embodiment according to the present invention, the insulation performance with respect to the operating voltage in the steady operation state of the conductor 2 that is insulated and supported by the insulating spacer 3 inside the metal container 1 whose inner surface is coated with the dielectric coating 7. In order to assure foreign matter, in conducting the foreign matter conditioning to the gas insulating device in which the insulating gas 4 is enclosed in the metal container 1 at a predetermined pressure, the pressure of the insulating gas 4 is lowered and the insulation performance of the insulating gas 4 is lowered. The foreign object 5 is easily moved, and a voltage corresponding to an electric field change curve C lower than the operating electric field E ₁ corresponding to the operating voltage in the steady operation state is applied to the conductor 2 to thereby cause the conductive foreign object 5 inside the metal container 1 to be moved. In order to facilitate the movement of the conductive foreign material 5 in a state in which the insulating performance of the insulating gas 4 is reduced, The conductive foreign material 5 is easily shifted from the [α] state in FIG. 3A to the [γ] state, and the conductive foreign material 5 is efficiently transferred to the low electric field portion formed by the particle trap 6 (see FIG. 1). It can be captured.

As described above, in the foreign matter conditioning method according to the first embodiment of the present invention, the insulation performance of the insulating gas 4 is lowered by lowering the pressure of the insulating gas 4. Therefore, it is not necessary to provide a vibration may be conditioned to easily state exercise the conductive materials 5 without higher than the operating field E _1.

  According to Embodiment 1 of the present invention, a metal container 1 having an inner surface covered with an insulating coating with a dielectric film 7 and a conductor 2 insulated and supported by an insulating spacer 3 inside the metal container 1 are provided. In order to ensure the insulation performance of the conductor 2 in the steady operation state, the conductive foreign matter 5 inside the metal container 1 is conditioned on the gas insulating device in which the insulating gas 4 having a predetermined pressure is sealed in the metal container 1. Since the conductive foreign matter 5 is conditioned inside the metal container 1 with the pressure of the insulating gas 4 lowered to reduce the insulating performance of the insulating gas 4, the pressure of the insulating gas 4 is reduced. By conducting the conditioning of the conductive foreign material 5 inside the metal container 1 in the lowered state, the inner surface of the metal container 1 is insulated and coated. The conductive materials 5 even in gas-insulated equipment can be captured efficiently conducting foreign substance 5 can be easily move that.

In the above description, the case of a gas insulating device in which a single insulating gas is sealed has been described as an example. However, for example, a gas insulating device in which a mixed gas of SF ₆ and N ₂ or an alternative gas other than SF ₆ is sealed. Has the same effect.

Embodiment 2. FIG.
A second embodiment according to the present invention will be described. In the second embodiment, the configuration of the gas insulating apparatus to which the foreign matter conditioning method in the second embodiment is applied has the same configuration as the configuration shown in FIG. 1 in the first embodiment, and the conductivity in the second embodiment. Conductive foreign matter 5 shown in FIGS. 3 (a) and 3 (b) described in comparison with FIGS. 2 (a) and 2 (b) in the first embodiment is shown in FIG. This exhibits the same behavior and electric field application status as the above and the electric field application status, and exhibits the same action.

In the first embodiment, the gas insulation device in which a single insulating gas is sealed is conditioned in a state where the gas pressure is lowered. However, in the second embodiment, for example, a mixture of SF ₆ and N ₂ is used. In the case of gas-insulated equipment in which two or more kinds of gases such as gas are sealed as the insulating gas 4 in order to ensure the insulation performance in the normal operation state of the conductor 2, the insulation performance is relatively low except for the gas having a relatively high insulation performance. In this state, foreign matter conditioning is performed in a state where only one gas is sealed and the insulating performance of the insulating gas 4 is lowered.
If two kinds of mixed gases Ga and Gb are used as the insulating gas 4, and the gas Gb has a lower insulating performance than the gas Ga, only the gas Gb having a relatively low insulating performance except for the gas Ga having a relatively high insulating performance is used. Foreign matter conditioning is performed in a state where the insulating gas 4 is sealed and the insulating performance of the insulating gas 4 is lowered.
When three kinds of mixed gases Ga, Gb, and Gc are used as the insulating gas 4 and the insulating performance is high in the order of the gas Ga, the gas Gb, and the gas c, the gas Ga having a relatively high insulating performance, or the gas Ga and With the exception of the gas Gb, the gas Gb and the gas Gc having relatively low insulation performance, or only the gas Gc is sealed as the insulation gas 4, and the foreign matter conditioning is performed in a state where the insulation performance of the insulation gas 4 is lowered.
As described above, the insulating gas 4 composed of two or more kinds of mixed gases is used, and the insulating performance of the insulating gas 4 is lowered by enclosing at least one of other arbitrary gases except for the gas having the highest insulating performance. In this state, it is possible to perform foreign object conditioning.

In this way, since the conductive foreign material 5 is likely to cause partial discharge, the conductive foreign material 5 can be moved even at an operating electric field E ₁ or less corresponding to the operating voltage in the steady operation state, and the foreign material conditioning is performed efficiently. Can be implemented.

  According to Embodiment 2 of the present invention, a metal container 1 having an inner surface covered with an insulating coating with a dielectric film 7 and a conductor 2 insulated and supported inside the metal container 1 are provided. In order to ensure the insulation performance in the steady operation state of the gas container in which the insulating gas 4 composed of two or more kinds of mixed gas is sealed in the metal container 1, the conductive foreign matter 5 inside the metal container 1 is conditioned. Since the conductive foreign material 5 is conditioned in the metal container 1 in a state where only the gas having a relatively low insulation performance is filled except for a gas having a relatively high insulation performance, the mixing of the two or more kinds is performed. Conductivity in the metal container 1 is filled with only the gas having a relatively low insulation performance except for the gas having a relatively high insulation performance among the insulating gas 4 made of gas. By performing the conditioning of the foreign matter 5, the foreign matter conditioning method can easily move the conductive foreign matter 5 and efficiently capture the conductive foreign matter 5 even in a gas-insulated device in which the inner surface of the metal container 1 is insulated. Can be obtained.

Embodiment 3 FIG.
Embodiment 3 according to the present invention will be described. In the third embodiment, the configuration of the gas insulating apparatus to which the foreign matter conditioning method in the third embodiment is applied has the same configuration as the configuration shown in FIG. 1 in the first embodiment, and the conductivity in the third embodiment. Conductive foreign matter 5 shown in FIGS. 3 (a) and 3 (b) described in comparison with FIGS. 2 (a) and 2 (b) in the first embodiment is shown in FIG. This exhibits the same behavior and electric field application status as the above and the electric field application status, and exhibits the same action.

  In the second embodiment, in a gas-insulated device in which two or more kinds of mixed gases are sealed as the insulating gas 4, only the gas having the lower insulating performance is sealed to reduce the insulating performance of the insulating gas 4. In the third embodiment, in the gas insulation apparatus in which two or more kinds of mixed gases are sealed as the insulation gas 4 in order to ensure the insulation performance in the normal operation state of the conductor 2, the conditioning is performed. By changing the mixing ratio of the insulating gas 4, the insulating performance of the insulating gas 4 is lowered, and the conductive foreign material 5 is conditioned in a state in which partial discharge of the insulating foreign material 5 is likely to occur. There is an effect similar to that of the second embodiment.

  According to Embodiment 3 of the present invention, a metal container 1 having an inner surface covered with an insulating coating with a dielectric film 7 and a conductor 2 insulated and supported by an insulating spacer 3 inside the metal container 1 are provided. In order to ensure the insulation performance of the conductor 2 in a steady operation state, the inside of the metal container 1 is a gas-insulated device in which an insulating gas 4 composed of two or more kinds of mixed gases is sealed in the metal container 1 with a mixing ratio as a predetermined value. When conditioning the conductive foreign material 5, the insulating gas 4 is mixed in a state different from a predetermined value to reduce the insulating performance of the insulating gas 4, thereby conditioning the conductive foreign material 5 inside the metal container 1. Since the insulating gas 4 composed of two or more kinds of mixed gases is in a state where the mixing rate is different from a predetermined value, the insulating performance of the insulating gas 4 is lowered before By conditioning the conductive foreign material 5 inside the metal container 1, the conductive foreign material 5 can be easily moved even in a gas-insulated device in which the inner surface of the metal container 1 is covered with insulation. A foreign matter conditioning method capable of capturing the foreign matter 5 can be obtained.

It is sectional drawing which shows the structure of the gas insulation apparatus to which the foreign material conditioning method of Embodiment 1 is applied. It is explanatory drawing which shows the behavior of the electroconductive foreign material when the inner surface of a metal container is not insulation-coated, and the diagram which shows the application condition of an electric field. It is explanatory drawing which shows the behavior of the conductive foreign material in case the inner surface of a metal container is insulation-coated, and a diagram which shows the application condition of an electric field.

Explanation of symbols

1 metal container, 2 conductor, 3 insulating spacer, 4 insulating gas, 5 conductive foreign matter, 6 particle trap, 7 dielectric coating.

Claims (4)

  A container having an inner surface coated with a dielectric coating and a conductor insulated and supported inside the container, and an insulating gas sealed in the container to ensure insulation performance in a steady operation state of the conductor When conditioning the conductive foreign matter in the container with respect to the gas insulation device, the foreign matter conditioning method is characterized in that the conductive foreign matter is conditioned in the container in a state where the insulation performance of the insulating gas is reduced. . A container having an inner surface coated with an insulating coating with a dielectric coating; and a conductor insulated and supported inside the container, and the insulating gas at a predetermined pressure is used to ensure insulation performance in a steady operation state of the conductor. In conditioning the conductive foreign matter in the container with respect to the gas insulation device sealed in the container, the conductive foreign matter in the container is reduced in a state where the insulating gas pressure is lowered to reduce the insulation performance of the insulating gas . A foreign matter conditioning method characterized by performing conditioning.
  A container having an inner surface coated with an insulating coating with a dielectric coating; and a conductor insulated and supported inside the container; in order to ensure insulation performance in a steady operation state of the conductor, A state in which the insulating performance of the insulating gas is reduced by excluding the gas having a relatively high insulating performance from the insulating gas when conditioning the conductive foreign matter in the container for the gas insulating device in which the insulating gas is sealed in the container. A method for conditioning foreign matter, comprising conducting conditioning of conductive foreign matter in the container. A container having an inner surface coated with an insulating coating with a dielectric coating; and a conductor insulated and supported inside the container; in order to ensure insulation performance in a steady operation state of the conductor, When conditioning the conductive foreign matter in the container for the gas-insulated equipment in which the insulating gas is mixed in the container at a predetermined value, the insulating gas is mixed with the insulating gas in a state different from the predetermined value. A foreign matter conditioning method characterized in that the insulating performance of the conductive material is reduced to condition the conductive foreign matter in the container.

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