JPH09294324A - Gas insulation bus bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen a partial increase in temperature in an upper section of a metal container where the increase in temperature is maximum and reduce the material cost since the materials of the metal container and a conductor can be changed to low-cost ones, by locating the central axis of the high-voltage conductor lower than that of the metal container. SOLUTION: The central axis of a high-voltage conductor 2 is located lower than that of a metal container 1. So, the high-voltage conductor 2 which is a source of heat comes near the bottom of the metal container 1 and the increase in temperature in an upper section of the metal container 1 where the increase in temperature is likely to be maximum can be lessened and thereby the increase in temperature in the entire container can be made even. By this, there is a margin for increase in temperature against an allowable temperature and therefore the materials for the metal container 1 and the high-voltage conductor 2 can be selected from a variety of materials and such a material that has a large resistance is with low cost can be used, resulting in the reduction in the cost. Furthermore, the diameter of the metal container 1 can be reduced and thereby the economical effect is increased and the size of the entire transforming station can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated busbar, and more particularly to an insulated busbar suitable for improving insulation performance and temperature characteristics.

[0002]

2. Description of the Related Art A conventional apparatus is disclosed in Japanese Patent Laid-Open Nos. 58-51715, 58-144514 and 2-7823. In the insulation spacer attachment part of, the center of the conductor is eccentric to the center of the metal container or the structure is such that a concave shape is formed in the lower direction of the conductor. At the position, the insulation strength was improved by using an insulation spacer having a longer insulation distance and an increased size.

Further, as described in JP-A-5-91630, a conductor is fixed and supported from above by an insulating spacer fixed above a metal container, and foreign matter is supplemented to the bottom of the metal container below the insulating spacer. Also, a gas-insulated bus bar having a recess having a work handhole function has been proposed.

[0004]

In the above conventional gas-insulated busbar, since the allowable electric field strength in the creeping direction of the insulating spacer for fixing and supporting the conductor in the metal container from below is lower than the allowable electric field strength in the insulating gas, insulation When foreign matter adheres to the surface of the spacer, dielectric breakdown easily occurs on the surface of the insulating spacer. Therefore, as a method of increasing the insulation distance along the insulating spacer surface, the conductor center axis is eccentric above the center axis of the metal container.At this time, the distance between the upper part of the metal container and the conductor becomes shorter, so The temperature rise is maximum at the upper part of the container, but this temperature rise is further increased locally. As a result, the dielectric strength can be improved by increasing the size of the insulating spacer, but there is a problem that the material of the conductor and the metal container must be an expensive low resistance material in order to reduce the temperature rise. .

An object of the present invention is to alleviate the local temperature rise in the upper part where the temperature rise of the metal container is maximum and to reduce the material cost by changing the material of the metal container and the conductor.

A further object of the present invention is to improve the insulating performance of the insulating spacer, to improve the dielectric strength by increasing the size of the insulating spacer, and to reduce the diameter of the metal container and reduce the cost.

[0007]

In order to achieve the above object, the present invention provides a cylindrical metal container in which an insulating gas is filled and which is at a ground potential, and a gas-insulated bus bar in which a high-voltage conductor is arranged in the metal container. In the above, the central axis of the high-voltage conductor is eccentric to the lower side with respect to the central axis of the metal container.

In order to achieve the above-mentioned object, the present invention provides a cylindrical metal container in which an insulating gas is filled and grounded, and a gas-insulated bus bar in which a high-voltage conductor is arranged in the metal container. The conductor is fixed and supported on the metal container by an insulating spacer provided on the upper side of the high-voltage conductor.

Further, in order to achieve the above object, the present invention eccentricizes the central axis of the high-voltage conductor downward with respect to the central axis of the metal container, and the eccentricity is greater than 15% of the diameter of the high-voltage conductor. The range is up to%.

In order to achieve the above object, according to the present invention, the central axis of the high-voltage conductor is eccentric to the central axis of the metal container downward, and the eccentricity is greater than 20% of the diameter of the high-voltage conductor. The range is up to%.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. 1 is a vertical cross-sectional view of the gas insulating bus bar of this embodiment, FIG. 2 is a cross-sectional view of the gas insulating bus bar viewed from the arrow AA in FIG. 1, and FIG. FIG. 5 is a cross-sectional view of the gas-insulated bus bar viewed from B, FIG. 4 is a graph showing the relationship between the temperature characteristics and the eccentricity ratio of the gas-insulated bus bar of this embodiment, and FIG.
3 is a graph showing the relationship between the insulation performance and the eccentricity ratio of the gas-insulated bus bar of this example.

As shown in FIGS. 1 to 5, the gas-insulated bus bar of this embodiment is arranged in a grounded metal container 1 (or simply referred to as a metal container 1) in which an insulating gas is mainly enclosed, and the grounded metal container 1. It is composed of an insulating spacer 3 or 4 for fixing and supporting the high-voltage conductor 2 and the high-voltage conductor 2. The central axis of the high-voltage conductor 2 is provided at a position eccentric to the lower side with respect to the central axis of the metal container 1.

The insulating spacer 3 is connected and fixedly supported to the metal container 1 and the high-voltage conductor 2 as follows, and fixedly supports the high-voltage conductor 2. A high voltage side embedded electrode 3a is attached to the lower side which is the high voltage side of the insulating spacer 3, and the high voltage side embedded electrode 3a is fixed to a mounting metal fitting 2a by a bolt or the like, and is mounted on the upper side of the high voltage conductor 2. The metal fitting 2a is fixed by a bolt or the like. On the other hand, the low-voltage side embedded electrode 3b is attached to the upper side of the insulating spacer 3 which is the low-voltage side, and the low-voltage side embedded electrode 3b is fixed to the mounting metal fitting 5 by bolts or the like, and is welded to the metal container 1 in advance. The mounting bracket 5 is supported on the mounted seat 1a by adjusting bolts 6 and the like. Here, the fixing and the fine adjustment are performed by the adjusting bolt 6. By processing only the upper side of the mounting portion of the high-voltage conductor 2 to the mounting metal fitting 2a, foreign substances contained in the hollow high-voltage conductor 2 are prevented from falling onto the bottom surface of the metal container 1.

Further, the insulating spacer 4 is connected and fixedly supported to the metal container 1 and the high voltage conductor 2 as follows, and fixedly supports the high voltage conductor 2. A high voltage side embedded electrode 4a is attached to the lower side of the insulating spacer 4, which is the high voltage side, and the high voltage side embedded electrode 4a is formed in a tubular shape and the high voltage conductor 2 is inserted therein. On the other hand, the low-voltage side embedded electrode 4b is attached to the upper side of the insulating spacer 4 which is the low-voltage side. Mounting seat 1
The mounting bracket 5 is supported on a by adjusting bolts 6 and the like. Here, the fixing and the fine adjustment are performed by the adjusting bolt 6. In addition, the high-voltage conductor 2 is connected to the cylindrical high-voltage side embedded electrode 4
Since it is inserted into a, foreign matter contained in the hollow high-voltage conductor 2 is prevented from falling.

In this embodiment, the center axis of the high-voltage conductor 2 is eccentric to the center axis of the metal container 1 below. The theoretical amount of eccentricity is the distance between the high-voltage conductor 2 and the metal container 1 above. Is longer than 100% and longer than before eccentricity up to 150%.

Since the central axis of the high-voltage conductor 2 is eccentric to the central axis of the metal container 1 as described above, the high-voltage conductor 2 that is a heat source approaches the bottom of the metal container 1 to cause the metal container 1 to move. It is possible to suppress the temperature rise in the upper part of the metal container 1 where the temperature rise is most likely to occur, and it is possible to make the temperature rise uniform throughout. For this reason, since there is a margin of increase in temperature with respect to the allowable temperature, there is a wide range of choices for the material of the metal container 1 or the high-voltage conductor 2, and it is possible to use a material having a large resistance value but low cost, Can reduce. Further, the diameter of the metal container 1 can be reduced, so that the economical efficiency can be improved and the size of the entire substation can be reduced.

Further, when the metal container having the same diameter as the conventional one is used, it is possible to attach the size-increasing insulating spacers 3 to 4, so that the creeping leakage resistance of the insulating spacer 3 or the insulating spacer 4 increases, The creeping electric field strength also decreases. Further, even if foreign matter is contained in the metal container 1, the foreign matter does not adhere to the insulating spacer 3 or the insulating spacer 4 because it falls downward, so that the insulating performance of the insulating spacer 3 or the insulating spacer 4 is improved. .

Next, the amount of eccentricity in one embodiment of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 shows the ratio (D /) of the conductor diameter (diameter) W of the high-voltage conductor in which the eccentric dimension D shown in FIGS. 2 and 3 is changed.
W), the maximum temperature rise value θ _H on the metal container 1,
9 is graph data showing a ratio (θ _H / θ _L ) to the minimum temperature rise value θ _L.

The ideal temperature distribution of the metal container is that the entire container is uniformly heated. Θ _H = θ _L (θ
_H / θ _L = 1.0) is desirable, and the farther from this value, the more the temperature difference is generated on the container. Then, as shown in the graph data, the central axis of the high-voltage conductor 2 is located below the central axis of the metal container 1 (D
/ W) value is made eccentric within the range of 15% to 40% to make the temperature difference of the container an ideal allowable range (within 10%).
It has been shown that it can be put in.

Further, FIG. 5 shows the conductor diameter (diameter) of the high-voltage conductor.
Regarding W, the ratio (E _G / E _S ) between the gas space withstand voltage value E _G and the insulating spacer withstand voltage value E _S is calculated with respect to the ratio (D / W) in which the eccentric dimension D shown in FIGS. 2 and 3 is changed. It is the graph data shown.

As for the withstand voltage condition, the gas space withstand voltage value E _G and the insulating spacer withstand voltage value E _S are such that the ratio E _G / E _S of the gas space withstand voltage value E _G and the insulating spacer withstand voltage value E _S is 1.0.
It shows that the whole metal container is made compact while maintaining the stability of pressure resistance. If the value of E _G / E _S is higher than this value, the gas is The space withstand voltage value E _G is higher than the insulating spacer withstand voltage value E _S , indicating that the gas space withstand voltage is high and the metal container is large, and when the value of E _G / E _S is low, the insulating spacer withstand voltage value E The withstand voltage of _S has lost to the withstand voltage value E _{G of the} gas space, indicating that the stability of the withstand pressure is not maintained.

The graph 52 in FIG. 5 shows E _G / E with respect to the ratio D / W of the outer diameter of the high-voltage conductor 2 to the inner diameter of the metal container.
A substantial upper limit of the value of _S is shown, and the graph 54 shows E _G / E with respect to D / W of the outer diameter of the high-voltage conductor 2 and the inner diameter of the metal container.
_It shows the practical lower limit of the value of _S. The portion of the gas insulated busbar indicated by the region 56 between the graphs 52 and 54 is used as a general design range. For example, the inner diameter of the metal container is 500 mm, the outer diameter of the high-voltage conductor is 150 mm, and the ratio D / It is used with the configuration set to W = 27 (%).

As shown in the graph data, in the present invention, the eccentricity of the central axis of the high-voltage conductor 2 below the central axis of the metal container 1 (D / W) is in the range of 20% to 50%. By doing so, it is shown that the value of E _G / E _S can be put in an ideal allowable range (within ± 5%).

Further, in the embodiment of the present invention, from the graphs of FIG. 4 and FIG. 5, the structure centered on the temperature distribution, and
It is possible to adopt a structure centered on withstand voltage, and further a structure having both of these characteristics.

That is, when the eccentricity value (D / W) is set to a low value, for example, if it is in the range of 15% to 20%, the size of the metal container is slightly large, but the temperature distribution characteristic is excellent. It is possible to provide a gas-insulated busbar, and if the temperature is in the range of 40% to 50%, the temperature distribution will not be uniform, and expensive members will have to be used. It becomes possible to provide an excellent gas-insulated bus bar. Then, if these conditions are combined so as to fall within the range of 20% to 40%, it becomes possible to provide a compact gas-insulated bus bar having excellent temperature distribution characteristics and excellent withstand voltage characteristics.

[0027]

As described above, according to the present invention, in the gas-insulated busbar in which the high-voltage conductor is arranged in the cylindrical metal container which is filled with the insulating gas and is set to the ground potential, the central axis of the metal container is provided. On the other hand, by making the central axis of the high-voltage conductor eccentric so that it is on the lower side, it becomes possible to maintain a uniform temperature distribution in the metal container.

Further, since the high-voltage conductor is supported and fixed by the columnar insulating spacer fixed to the upper part of the metal container,
It is possible to provide a gas-insulated bus bar that can improve the insulating performance, suppress a local temperature rise that occurs at the upper part of the metal container, and contribute to the improvement of the economical efficiency and the downsizing of the substation.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a gas-insulated bus bar showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a graph showing the relationship between the temperature characteristics and the eccentricity ratio of the gas-insulated bus bar of this embodiment.

FIG. 5 is a graph showing the relationship between the insulation performance and the eccentricity ratio of the gas-insulated bus bar of this example.

[Explanation of symbols]

1 ... Metal container, 1a ... Mounting seat, 2 ... High-voltage conductor, 2a, 5
... Mounting metal fittings 3, 4 ... Insulating spacers 3a, 4a ... High voltage side embedded electrodes, 3b, 4b ... Low voltage side embedded electrodes, 6 ... Adjustment bolts.

Claims (5)

[Claims] 1. A cylindrical metal container in which an insulating gas is filled to have a ground potential, and a gas-insulated bus bar in which a high-voltage conductor is arranged in the metal container. A gas-insulated bus bar having a central axis eccentric to the lower side. 2. The gas-insulated bus bar according to claim 1, wherein the high-voltage conductor is fixedly supported on the metal container by an insulating spacer provided above the high-voltage conductor. 3. The gas-insulated bus bar according to claim 2, wherein a column-shaped insulating spacer is used as the insulating spacer. 4. The gas-insulated bus bar according to claim 1, wherein the center axis of the high-voltage conductor is eccentric to the center axis of the metal container downward and the eccentricity is 15% of the diameter of the high-voltage conductor. A gas-insulated bus bar having a larger range up to 40%. 5. The gas-insulated bus bar according to claim 4, wherein the center axis of the high-voltage conductor is eccentric downward with respect to the center axis of the metal container, and the amount of eccentricity is 20% of the diameter of the high-voltage conductor. A gas-insulated bus bar having a larger range up to 40%.