Patent Description:
In conventional gas insulated switchgears, there is a gas insulated switchgear mainly composed of three circuits, which is referred to as a ring main unit for distribution and collection of electrical energy. For example, if the gas insulated switchgear is designed for distribution, each circuit of the three circuits is used for the purpose of drawing-in from the outside, drawing-out to the outside, and electric power supply to distribution destinations.

With the aim of function integration and size reduction of gas insulated switchgear, there is a gas insulated switchgear that integrates switches and connection destinations of three circuits. Furthermore, in order to flexibly cope with apparatuses and the number of circuits which constitute the circuits, there also exist ways in which a gas insulated switchgear is configured in a unit of one board including one circuit or two circuits and these gas insulated switchgears are combined.

In the aforementioned conventional gas insulated switchgears, a gas insulated switchgear of Patent Document <NUM> has a problem in that it is difficult to cope with a change of application circuits, such as an increase or a decrease in the number of circuits and addition of measurement devices. On the other hand, in the case of a gas insulated switchgear of Patent Document <NUM>, although a circuit can be properly configured, an insulation distance against the ground, that is, the insulation distance between a high voltage portion and a ground portion (pressure tank or housing) needs to be secured in each surface; and accordingly, size reduction of the gas insulated switchgear is limited.

Patent Document <NUM> relates to a gas-insulated switchgear configured from: sealed vessels in which an insulated gas is encapsulated; a breaker disposed in a manner so that the axial center direction of the drive axis thereof is horizontal and parallel to the anterior surface of sealed vessel; a first disconnector that is disposed below the breaker and that electrically connects to the breaker; a bus of which one end connects to the breaker and the other end extends in the axial center direction of the drive axis of the breaker; a second disconnector that is electrically connected to the bus; a cable connector that is led out from the first disconnector to sealed vessel; and a cable connector that is led out from the second disconnector to sealed vessel.

Patent Document <NUM> relates to a gas-insulated switching installation which is provided with a separately manufactured high-voltage fuse panel which has a prismatic housing. The fuse panel can be equipped with plug connections and, if required, can be installed physically separately from the switching installation.

The present invention has been made to solve the above described problem, and an object of the present invention is to provide a gas insulated switchgear capable of reducing the outline dimensions of the gas insulated switchgear and obtaining necessary circuit configuration.

According to the invention, the problem is solved by means of a gas insulated switchgear as defined in independent claim <NUM>. Advantageous further developments of the gas insulated switchgear according to the invention are set forth in the dependent claims.

According to the gas insulated switchgear according to the present invention, since the first opening portion of the basic unit portion and the second opening portion of the variable unit portion are joined facing each other to form into one constitutional body to be configured in one gas compartment, an insulating spacer or the like that partitions between them is not needed: and therefore, there can be obtained a gas insulated switchgear in which an insulation space necessary for the periphery thereof is not needed and outline dimensions can be made smaller as a whole.

Furthermore, in the case where a plurality of second disconnecting switches are accommodated in the inside of the second pressure tank, a partition between the disconnecting switches does not exist: and therefore, an insulation space necessary for between the partition and the disconnecting switch is not needed and outline dimensions can be made smaller as a whole.

Hereinafter, Example <NUM> will be described with reference to <FIG>. Then, in each of the drawings, identical or equivalent members and portions will be described with the same reference numerals (and letters) assigned thereto. <FIG> is a front view showing a gas insulated switchgear according to Example <NUM>. <FIG> is a side view showing the gas insulated switchgear according to Example <NUM>.

<FIG> is a plan view showing the gas insulated switchgear according to Example <NUM>. <FIG> is a sectional view taken along the line B-B of <FIG>, which shows the gas insulated switchgear according to Example <NUM>. <FIG> is a sectional view taken along the line A-A of <FIG>, which shows the gas insulated switchgear according to Example <NUM>.

<FIG> is a single line connection diagram showing the gas insulated switchgear having the structure of <FIG> according to Example <NUM>. <FIG> is a single line connection diagram showing a gas insulated switchgear having the structure of <FIG> according to Example <NUM>. <FIG> is a front sectional view showing the gas insulated switchgear according to Example <NUM>. <FIG> is a side sectional view showing the gas insulated switchgear according to Example <NUM>.

A gas insulated switchgear <NUM> in this Example <NUM> includes a basic unit portion <NUM> including: a first pressure tank 1a in which insulating gas such as hexafluoride (SF6) gas, dry air, and nitrogen is sealed, and is provided with a first opening portion 1a1 at one surface of the first pressure tank 1a; a circuit breaker <NUM> which is provided with, for example, a vacuum interrupter 2b in the inside, and interrupts a large current; a first disconnecting switch 3a that connects and disconnects a main circuit; a first bushing 4a that connects the main circuit to an external apparatus; a connection conductor 7a that connects the circuit breaker <NUM> to the first disconnecting switch 3a; and a connection conductor 7b that connects the first disconnecting switch 3a to the first bushing 4a.

Then, the gas insulated switchgear <NUM> includes a variable unit portion <NUM> including: a second pressure tank 1b in which insulating gas such as SF6 gas, dry air, and nitrogen is sealed, and is provided with a second opening portion 1b1 facing the first opening portion 1a1 at one surface of the second pressure tank 1b; three busbars <NUM> for three phases which are each connected to the circuit breaker <NUM>, and are each horizontally disposed with respect to the front of the gas insulated switchgear <NUM> and the ground; a second disconnecting switch 3b which is connected to the busbar <NUM> at one end, and connects and disconnects a main circuit; a third bushing 4b which is connected to the busbar <NUM> at one end, and is connected to an external apparatus; a second bushing 4c which is connected to the other end portion of the second disconnecting switch 3b, and is connected to an external apparatus; a connection conductor 8a which connects the busbar <NUM> to the second disconnecting switch 3b; a connection conductor 8b which connects the busbar <NUM> to the third bushing 4b; and a connection conductor 8c which connects the second disconnecting switch 3b to the second bushing 4c.

Then, the first opening portion 1a1 of the first pressure tank 1a and the second opening portion 1b1 of the second pressure tank 1b are butted and joined facing each other to form into one constitutional body. The first pressure tank 1a and the second pressure tank 1b are formed into one constitutional body and the inside thereof can be configured as one gas compartment. Thus, an insulating spacer or the like that partitions between them does not need to be provided; and therefore, there can be obtained a gas insulated switchgear in which an insulation space necessary for the periphery thereof is not needed, and outline dimensions can be made smaller as a whole.

Furthermore, in the case where a plurality of the second disconnecting switches are accommodated in the inside of the second pressure tank, the partition between the disconnecting switches does not exist; and therefore, an insulation space necessary for between the partition and the disconnecting switch is not needed and outline dimensions can be made smaller as a whole.

Incidentally, in the standard gas insulated switchgear <NUM>, the first disconnecting switches 3a constitute a three position switch and the second disconnecting switches 3b constitute a three position switch, each three position switch performing three operations of connecting, disconnecting, and grounding.

The first pressure tank 1a of the basic unit portion <NUM> is supported by a base frame <NUM>. Furthermore, a circuit breaker operating mechanism 2a of the circuit breaker <NUM>, a first disconnecting switch operating mechanism 3d of the first disconnecting switch 3a, and control components are placed on the outside of the first pressure tank 1a and are accommodated in an compartment <NUM> for protection. The compartment <NUM> is also supported by a base frame <NUM>. The compartment <NUM> protects by covering an exposed portion of the first bushing 4a on the outside of the tank and the outer periphery of the cable terminal <NUM> to be connected to the exposed portion.

Then, in order to avoid spreading the influence of an unexpected fault, a partition <NUM> is disposed between a cable installed place and an installed place of the circuit breaker operating mechanism 2a of the circuit breaker <NUM>, the first disconnecting switch operating mechanism 3d, or the like to partition so as to separate both spaces.

Furthermore, an annular current transformer <NUM> for main circuit current measurement is attached on the outer periphery of the first bushing 4a protruded to the outside of the first pressure tank 1a.

The second pressure tank 1b of the variable unit portion <NUM> is supported by a base frame <NUM>. Furthermore, a second disconnecting switch operating mechanism 3e of the second disconnecting switch 3b and control components are placed on the outside of the tank and are accommodated in an compartment <NUM> in order to protect an internal structure by separating from external environment of the gas insulated switchgear <NUM>.

The compartment <NUM> is also supported by the base frame <NUM>. The compartment <NUM> also protects an exposed portion of the second bushing 4c on the outside of the second pressure tank 1b and a cable terminal <NUM> to be connected to the exposed portion. Then, in order to avoid spreading the influence of an unexpected fault, a partition <NUM> is disposed between a cable installed place and an installed place of the second disconnecting switch operating mechanism 3e and the like to separate spaces of the second disconnecting switch operating mechanism 3e portion and the cable connection portion.

Further, in order to protect an exposed portion of the bushing 4b on the outside of the second pressure tank 1b and the cable terminal <NUM> to be connected to the exposed portion are accommodated in an compartment <NUM>; and the compartment <NUM> is supported by the second pressure tank 1b and the base frame <NUM>.

The compartment <NUM> and the compartment <NUM> are connected to a control box <NUM> to be a structure that can dispose necessary control circuits. The control box <NUM> is supported by the base frame <NUM>.

<FIG> is a single line connection diagram and the most right side circuit of <FIG> shows a circuit of the basic unit portion <NUM>. Circuits other than that and a busbar that commonly connects those circuits show a circuit of the variable unit portion <NUM>. The circuit of the basic unit portion <NUM> is a generally this circuit and fulfills a function as a circuit to be connected to a drawing-in portion.

On the other hand, it is assumed that the circuit of the variable unit portion <NUM> is fluctuated by: the number of circuits in which the gas insulated switchgear <NUM> is externally connected, that is, by the sum of one drawing-in circuit and the number of drawing-out circuits; and switching apparatuses, measurement devices, and the number of connection cables which are to be accommodated. The shapes of the installed apparatus of the variable unit portion <NUM> and the second pressure tank 1b are changed in accordance with fluctuating elements.

As an example, there is shown a case example where the number of circuits and the number of connection cables are changed. <FIG>, <FIG> show a single line diagram, a front sectional view, and a side sectional view, respectively. <FIG> shows a circuit in which one of the number of circuits is reduced from <FIG> and the number of connection cables is changed from one to two.

The structure of the gas insulated switchgear <NUM> in this case becomes as shown in <FIG>. In the front sectional view of <FIG>, the cable terminal <NUM> is increased to two branches; and in the side sectional view of <FIG>, it becomes a structure in which the third bushing 4b and the cable terminal <NUM> are deleted.

The insulation distance between the respective circuits, especially, between the circuits in the variable unit portion <NUM> can be reduced by enclosing a plurality of circuits in one gas compartment. In <FIG>, there exists only an insulation space between each other's apparatuses in between two second disconnecting switches 3b. If, in the case of the gas insulated switchgear in which the respective circuits are individually configured as disclosed in Patent Document <NUM>, there exists a grounded partition (pressure tank wall) between the apparatuses; and an insulating space needs to be provided between each apparatus and the partition.

These partitions are deleted in Example <NUM> and a plurality of circuits is accommodated in one gas compartment, whereby reduction in outline dimensions of the gas insulated switchgear <NUM>, especially, width dimension can be achieved.

The gas insulated switchgear <NUM> is divided into two portions of the basic unit portion <NUM> and the variable unit portion <NUM>, whereby the basic unit portion <NUM> can be manufactured as a standard unit in any application circuit. Therefore, planned production such as stocking of members can be made and cost reduction can be achieved.

Furthermore, as shown in <FIG>, it is structured such that the connection circuit excluding the second disconnecting switches 3b of the variable unit portion <NUM> is directly connected to the busbar <NUM>, and the dimensions and structure of the second pressure tank 1b are made common to the case where the circuit excluding the second disconnecting switches 3b does not exist (<FIG>), whereby types of the pressure tanks are reduced and planned production and cost reduction can be achieved.

The control box <NUM> is formed into a structure capable of accommodating control devices necessary for the maximum condition of an application circuit of the gas insulated switchgear <NUM>, and it is structured such that the control box <NUM> is supported by only the base frame <NUM>, whereby the control box <NUM> can be made common even when the circuit condition is changed and planned production and cost reduction of the control box <NUM> can be achieved.

As described above, the gas insulated switchgear <NUM> is divided into two portions of the basic unit portion <NUM> and the variable unit portion <NUM>, whereby the basic unit portion <NUM> can be manufactured as a standard unit in any application circuit. Therefore, planned production such as stocking of members can be made and cost reduction can be achieved.

An Embodiment of the present invention will be described with reference to <FIG>. Then, in the drawing, identical or equivalent members and portions will be described with the same reference numerals (and letters) assigned thereto. <FIG> is a front sectional view showing a gas insulated switchgear according to the Embodiment of the present invention.

In <FIG>, description of portions similar to the aforementioned Example <NUM> will be omitted. In <FIG>, a first opening portion 1c1 is made small by providing an inclined portion 1c2 in which a part of the bottom surface of a first pressure tank 1c of a basic unit portion <NUM> is made incline; a second opening portion 1d1 of a second pressure tank 1d of a variable unit portion <NUM> is made small by adjusting to the first opening portion 1c1; and the first opening portion 1c1 of the first pressure tank 1c of the basic unit portion <NUM> and the second opening portion 1d1 of the second pressure tank 1d of the variable unit portion <NUM> are butted and joined.

As described above, the shape of the first pressure tank 1c is changed so that a space where there exists no installed apparatus is reduced, whereby a gas compartment space can be reduced and therefore the amount of usage of insulating gas can be reduced. Furthermore, the first opening portion 1c1 and the second opening portion 1d1 are made small, whereby reliability of an airtight sealing portion is improved and fastening work in joining the unit portions can be reduced.

Example <NUM> will be described with reference to <FIG> and <FIG>. Then, in each of the drawings, identical or equivalent members and portions will be described with the same reference numerals (and letters) assigned thereto. <FIG> is a side sectional view showing a gas insulated switchgear according to Example <NUM>. <FIG> is a plan sectional view showing a gas insulated switchgear according to Example <NUM>.

In this Example <NUM>, a second opening portion 1f1 of a variable unit portion <NUM> having a second pressure tank 1f is butted and joined to a first opening portion 1e1 on a rear portion of a basic unit portion <NUM> having a first pressure tank 1e to form into one constitutional body. Then, a second disconnecting switch 3b whose one end is connected to one end portion of a circuit breaker <NUM> and is branched and connected for each circuit from each of vertically extended three busbars for three phases <NUM>, and a second bushing 4c and a cable terminal <NUM> which are connected to the end of the second disconnecting switch 3b are arranged upward in a pile-up direction for each circuit.

Furthermore, in <FIG>, a cable terminal <NUM> is connected at an end portion of a connection conductor led out to the left direction from one end of the circuit breaker <NUM> via a third bushing 4b which passes through and is attached to a wall portion of the second pressure tank 1f.

Furthermore, in <FIG>, a main circuit branched from the second disconnecting switch 3b passes through a wall of the second pressure tank 1f by the second bushing 4c and one end portion thereof is connected to the cable terminal <NUM>. In <FIG>, one shown by a circular dashed line at the midpoint of the cable terminal <NUM> shows a cable that is extended downward. As shown in <FIG>, vertically extended cables for three phases do not interfere with each other by shifting the second bushings 4c for three phases from side to side and therefore it becomes easy to connect the cable terminal <NUM> to the second bushing 4c.

As described above, the busbars <NUM> are vertically extended and branch circuits therefrom are configured so as to vertically pile-up, whereby, for example, like a tower for a wind turbine, such a configuration can easily cope with a case where restriction in a ceiling direction is relatively small although the installation area of the gas insulated switchgear is narrow.

In such a case, branch main circuits connected correspondingly to respective circuits are arranged so as to vertically pile-up even when the number of circuits of electric power lines that connect between towers for respective wind turbines is increased, whereby it can easily cope with circuit connection of a plurality of electric power lines even when the installation area is narrow.

Incidentally, in this Example <NUM>, there is shown an example configured such that the busbars <NUM> are vertically extended and the branch circuits therefrom are vertically piled up; however, the example is not limited to this; and even when the busbars <NUM> are not arranged in a vertical direction, but, for example, are arranged with being inclined vertically (i.e. obliquely), such a configuration can easily cope with connection of a plurality of circuits even when the installation area is narrow although the installation area increases as compared to the above case example.

Incidentally, the present invention can freely combine the respective embodiments and appropriately modify and/or omit the respective embodiments within the scope of the present invention, as defined by the claims.

Claim 1:
A gas insulated switchgear (<NUM>) comprising: a basic unit portion (<NUM>) configured by a standard unit and a variable unit portion (<NUM>),
the basic unit portion (<NUM>) including:
- a first pressure tank (1c) in which insulating gas is sealed, and a first opening portion (1c1) is provided in at least one surface of the first pressure tank (1c);
- a circuit breaker (<NUM>) which is arranged in the inside of the first pressure tank (1c), and configured to interrupt a large current;
- a first disconnecting switch (3a) which is connected to the circuit breaker (<NUM>), and configured to disconnect a main circuit; and
- a first bushing (4a) configured to connect the main circuit to an external apparatus, and
the variable unit portion (<NUM>) including:
- a busbar (<NUM>) which is connected to one side terminal of the circuit breaker (<NUM>);
- a second pressure tank (1d) in which insulating gas is sealed, a second opening portion (1d1) facing the first opening portion (1c1) is provided in at least one surface of the second pressure tank (1d), wherein the busbar (<NUM>) is provided in the second pressure tank (1d);
- one or more second bushings (4c) passing through a wall of the second pressure tank (1d), and configured to connect an internal main circuit of the second pressure tank (1d) to an external apparatus; and
- one or a plurality of second disconnecting switches (3b) which is arranged between the busbar (<NUM>) and the one or more second bushings (4c), and disconnects the main circuit,
characterised in that:
the first opening portion (1c1) of the first pressure tank (1c) and the second opening portion (1d1) of the second pressure tank (1d) are butted and joined facing each other to form into one constitutional body so that the inside of the first pressure tank (1c) and the second pressure tank (1d) is configured as one gas compartment,
wherein the first opening portion (1c1) is made small by making the bottom surface (1c2) of the first pressure tank (1c) of the basic unit portion (<NUM>) incline and the second opening portion (1d1) of the second pressure tank (1d) of the variable unit portion (<NUM>) is made small by adjusting to the first opening portion (1c1).