JP2019022298A - Metal closing type switch gear - Google Patents

Abstract

To provide a metal closing type switch gear capable of suppressing the large sized due to a high voltage, and improving insulation reliability.SOLUTION: A metal closing type switch gear comprises: a vacuum insulation container; a vacuum valve including a pair of electrodes which are provided in an inner part of the vacuum insulation container and can be contacted and separated, and a cylindrical arc shield that is provided so as to surround the circumference of the electrode; a metal housing that houses the vacuum valve in an inner part, and of which the inner part is in a gas atmosphere of an insulation medium; and an intermediate container that houses the vacuum valve in the inner part, is housed in the inner side of the metal housing, and of which the inner part is in the gas atmosphere of the insulation medium. A pressure in the intermediate container is the pressure of between the pressure in the vacuum insulation container and the pressure of the outer side of the intermediate container.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a metal closed switchgear.

  Conventionally, as a metal closed type switchgear, an opening / closing device such as a vacuum valve is housed in a metal housing box made of a metal box, and the atmosphere around the vacuum valve in the metal housing box is changed to a high-pressure insulating medium. The metal closed type switchgear which is made of gas is used.

  When this type of metal closed switchgear is increased in voltage, it is necessary to increase not only the vacuum valve but also the ground and withstand voltage. For this reason, measures such as increasing the size of the vacuum valve, increasing the insulation distance from the ground, or increasing the gas pressure of the insulating medium from the ground are required. However, if the gas pressure of the insulating medium is high, the pressure difference from the inside of the vacuum valve becomes large and the airtightness is lowered, leading to a decrease in insulation reliability.

  Further, when the metal closed switchgear having the above-described configuration is configured by a one-point vacuum valve, the vacuum valve is increased in size. The breakdown voltage in vacuum does not increase in proportion to the gap length, but increases logarithmically. That is, as the distance between the electrodes becomes longer, it is difficult to obtain the effect of expanding the distance between the electrodes. Therefore, when the rated voltage is relatively high, it is necessary to increase the insulation distance in vacuum, and it is inevitable that the vacuum valve becomes large.

JP 2003-77376 A

  As described above, in the metal closed type switchgear, there is a problem that an increase in voltage leads to an increase in size and a decrease in insulation reliability.

  An object of the present invention is to provide a metal closed switchgear that can suppress an increase in size due to a high voltage and can improve insulation reliability.

  The metal closed type switchgear according to the embodiment includes a vacuum insulating container, a pair of electrodes that can be brought into and out of contact with the vacuum insulating container, and a cylindrical arc shield that is provided so as to surround the electrode. The vacuum valve which has these. Further, the vacuum valve is housed inside, and a metal housing box in which the inside is a gas atmosphere of an insulating medium, and the vacuum valve is housed inside, and is housed inside the metal housing box to insulate the inside. An intermediate container having a medium gas atmosphere. The pressure in the intermediate container is a pressure between the pressure in the vacuum insulating container and the pressure outside the intermediate container.

The figure which shows typically the cross-sectional structure of the metal closed type switchgear of 1st Embodiment. The figure which shows typically the cross-sectional structure of the metal closed type switchgear of 2nd Embodiment. The figure which shows typically the cross-sectional structure of the metal closed type switchgear of 3rd Embodiment. The figure which shows typically the cross-sectional structure of the metal closed type switchgear of 4th Embodiment.

  Hereinafter, a metal closed switchgear according to an embodiment will be described with reference to the drawings.

(First embodiment)
First, the configuration of the metal closed switchgear according to the first embodiment will be described with reference to FIG. Although FIG. 1 (the same applies to FIGS. 2 to 4) shows the configuration of only one phase of the metal-closed switchgear, usually the same configuration is arranged for three phases.

  As shown in FIG. 1, the metal closure type switchgear 100 according to the first embodiment includes a metal storage box (metal closure board) 110, and a vacuum valve 120 is provided inside the metal storage box 110. Contained. The metal storage box 110 can be hermetically closed to store the insulating medium gas.

The vacuum valve 120 includes a vacuum insulating container 121 that can be hermetically closed. Inside the vacuum insulating container 121, a pair of electrodes 122a and 122b that can be contacted and separated are disposed so as to face each other, and a cylindrical arc shield 123 is provided so as to surround the electrodes 122a and 122b. Is arranged. The arc shield 123 is made of, for example, stainless steel. The inside of the vacuum insulating container 121 is a high vacuum atmosphere, and is set so that, for example, the internal pressure becomes a predetermined pressure (P1) of 10 ⁻² Pa or less.

  Moreover, the metal closed switchgear 100 of the first embodiment includes an intermediate container 130 that houses the vacuum valve 120 inside and is housed inside the metal housing box 110. The intermediate container 130 can be hermetically closed. The space around the vacuum valve 120 in the intermediate container 130 is filled with an insulating medium gas to form an insulating medium gas atmosphere.

  In addition, the space around the intermediate container 130 inside the metal storage box 110 is filled with an insulating medium gas, which is an insulating medium gas atmosphere. The intermediate container 130 is made of a conductive material such as metal and connected to the ground potential. However, the intermediate container 130 may be made of an insulating material.

The pressure (P 2) in the space around the vacuum valve 120 inside the intermediate container 130 is equal to the pressure (P 1) inside the vacuum insulation container 121 of the vacuum valve 120 and the pressure inside the metal container 110 inside the intermediate container 130. It is set to be a pressure between the pressure in the external space (P3). That is, the pressure of each part is P3>P2> P1
It is set to become.

The insulating medium gas filled in the metal storage box 110 and the intermediate container 130 is filled in order to maintain insulation from the ground. As such an insulating medium gas, for example, SF ₆ gas or dry air can be used. The internal pressure of the metal storage box 110 is, for example, about 0.1 MPa, and the internal pressure of the intermediate container 130 is, for example, about 0.05 MPa.

  Of the pair of electrodes 122a and 122b of the vacuum valve 120, one electrode 122a is connected to a fixed energizing shaft 124a. The movable electrode 124b is connected to the other electrode 122b. The movable energizing shaft 124 b is led out to the outside of the vacuum insulating container 121 through a vacuum sealing mechanism 125 such as a bellows, and is mechanically connected to an insulating rod 151 connected to the driving mechanism 150. The electrode 122b and the movable-side energizing shaft 124b are movable in the left-right direction in FIG. 1 by the drive mechanism 150, and are configured to connect and block the electric flow path by being separated from and contacting the electrode 122a. Yes.

  Note that a sealing member 131 that hermetically seals while permitting the movement of the insulating rod 151 is disposed in a through portion of the insulating rod 151 in the intermediate container 130. In addition, an insulating sealing member 132 is provided in the penetrating portion of the movable side energizing shaft 124b to hermetically seal and insulate while allowing movement of the movable side energizing shaft 124b. Further, an insulating sealing member 133 for hermetically sealing and insulating is disposed in the through portion of the fixed-side energizing shaft 124a.

  In the metal closed type switchgear 100 having the above configuration, when the rated voltage is increased, in order to insulate from the ground, the insulation distance to the ground is increased or the pressure of the insulating medium gas for insulation from the ground is increased. There must be.

Increasing the insulation distance from the ground leads to an increase in size. On the other hand, when the pressure of the insulating medium gas inside the metal storage box 110 is increased, the pressure difference from the pressure in the vacuum insulating container 121 of the vacuum valve 120 (for example, 10 ⁻² Pa or less) becomes large, so the vacuum valve 120 There is a possibility that the airtightness of the metal will be lowered and insulation reliability will be lowered.

  In the metal closed switchgear 100 of the present embodiment, even if the pressure of the insulating medium gas inside the metal storage box 110 is increased, the pressure of the intermediate container 130 is changed between the pressure in the metal storage box 110 and the vacuum insulating container 121. By setting the pressure between the inner pressure and the inner pressure, it is possible to suppress a decrease in insulation reliability due to a decrease in the airtightness as described above. In addition, an increase in size of the metal closed switch gear 100 can be suppressed.

  Thus, in the metal closed type switchgear 100 of this embodiment, while being able to suppress the enlargement by high voltage increase, the improvement of insulation reliability can be aimed at.

(Second Embodiment)
Next, the configuration of the metal closed switch gear 101 according to the second embodiment will be described with reference to FIG. In FIG. 2, parts corresponding to those of the metal closed switchgear 100 shown in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  In the metal closed switchgear 101 of the first embodiment described above, an intermediate container 130 is provided, and this intermediate container 130 is set to, for example, a ground potential. For this reason, the electric potential of the arc shield 123 becomes low compared with the case where the intermediate container 130 is not provided. Therefore, the potential difference between the arc shield 123 and the electrodes 122a and 122b becomes large.

  Therefore, in the metal closed switch gear 101 according to the second embodiment, the voltage dividing capacitor 160 is provided in the arc shield 123 and the intermediate container 130 outside the vacuum insulating container 121 of the vacuum valve 120. Yes. The voltage dividing capacitor 160 is disposed between the electric flow path on the electrode 122a side and the arc shield 123, and between the electric flow path on the electrode 122b side and the arc shield 123, respectively.

  Thus, by providing the voltage dividing capacitor 160, the potential of the arc shield 123 can be controlled to 50%, and the potential difference between the arc shield 123 and the electrodes 122a and 122b can be reduced. Thereby, insulation reliability can be improved.

(Third embodiment)
Next, the structure of the metal closed type switchgear 102 concerning 3rd Embodiment is demonstrated with reference to FIG. 3, parts corresponding to those of the metal closed switchgear 100 shown in FIG. 1 and the metal closed switchgear 101 shown in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted. .

  In the metal closed switchgear 102 according to the third embodiment, the intermediate container 130 constituting the metal closed switchgear 101 of the second embodiment, the vacuum valve 120 accommodated therein, and the like are combined into one metal storage box. A plurality (three in FIG. 3) are accommodated in the interior of 110.

  The plurality of vacuum valves 120 are connected in series, and each vacuum valve 120 is driven by a drive mechanism 150 provided for each vacuum valve 120. By adopting such a configuration, it is possible to easily increase the voltage by combining a plurality of units including the small intermediate container 130 and the vacuum valve 120 accommodated therein.

(Fourth embodiment)
Next, the structure of the metal closed type switchgear 103 concerning 4th Embodiment is demonstrated with reference to FIG. In FIG. 4, the portions corresponding to the metal closed switch gear 100 shown in FIG. 1, the metal closed switch gear 101 shown in FIG. 2, and the metal closed switch gear 102 shown in FIG. The reference numerals are attached, and duplicate descriptions are omitted.

  As shown in FIG. 4, in the metal closed switchgear 103 according to the fourth embodiment, the insulating rod 151 for driving each vacuum valve 120 in the configuration of the metal closed switchgear 102 according to the third embodiment. Are connected to one shaft 152, and are configured to be collectively operated by a single drive mechanism 150. By adopting such a configuration, it is possible to simultaneously open the plurality of vacuum valves 120 when the accident current is interrupted, and it is possible to improve the reliability of the accident current interrupting performance.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  100, 101, 102, 103... Metal closed type switchgear, 110... Metal housing box (metal closing board), 120... Vacuum valve, 121 ... Vacuum insulating container, 122 a, 122 b. Arc shield, 124a... Fixed side energizing shaft, 124b .. movable side energizing shaft, 125... Vacuum sealing mechanism, 150... Driving mechanism, 151.

Claims (5)

A vacuum valve having a vacuum insulating container, a pair of electrodes that can be contacted and separated provided inside the vacuum insulating container, and a cylindrical arc shield that is provided so as to surround the periphery of the electrode;
A metal storage box that houses the vacuum valve inside, and the inside is a gas atmosphere of an insulating medium;
The vacuum valve is housed inside, and is housed inside the metal housing box, and includes an intermediate container in which the inside is a gas atmosphere of an insulating medium,
The metal closed switchgear characterized in that the pressure in the intermediate container is a pressure between the pressure in the vacuum insulating container and the pressure outside the intermediate container. 2. The metal closed switchgear according to claim 1, wherein the pressure in the vacuum insulating container is 10 ⁻² Pa or less.   The metal closed switchgear according to claim 1 or 2, wherein a capacitor for controlling the electric potential of the arc shield is provided in the intermediate container.   3. The metal closed switchgear according to claim 1, wherein the intermediate container is made of an insulating material.   The said metal container is arrange | positioned with two or more said intermediate containers which accommodated the said vacuum valve in the inside, The said vacuum valve was electrically connected in series, The Claim 1 thru | or 4 characterized by the above-mentioned. Metal closed switchgear as described.

Images