JPS6115652B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to gas-insulated electrical equipment, and more particularly to a closed circuit constructed between a pedestal supporting the electrical equipment and a grounding network buried underground.

A connection method as shown in FIG. 1 of the accompanying drawings has been used to connect the frame of a conventional gas-insulated electric device to a grounding network.

That is, in the figure, code 1 is the bus line,
2 _-1 and 2 _-2 are tanks in which the bus bar 1 is housed and filled with insulating gas, and the tank 2 _-1 and the tank 2 _-2 are electrically insulated. Next, _3-1 and _3-2 are stands supporting the tanks _2-1 and _2-2 , and _4-1 and _4-2 are the grounding wires 5 and 6 provided on the stands _3-1 and _3-2 , respectively. The fixture 7 is part of a grounding network buried underground, and is the main grounding wire to which the grounding wires 5 and 6 are connected. Note that 8 indicates the ground.

Since the conventional device is configured in this way, when current flows through the bus 1, the following connections occur: Tank 2 _-1 - Frame 3 _-1 - Fixture 4 _-1 - Ground wire 5 - Main ground wire 7 - Ground wire 6 - Fixture 4 _-2 - Frame 3 _-2 - Tank 2 An induced current flows in the closed circuit of _-1 . This is caused by the induced voltage generated as a result of the magnetic flux generated by the current flowing through the bus bar 1 interlinking with the closed circuit. As a result, the grounding wire becomes overheated, which is dangerous if the part is exposed to the ground surface, and may also cause the grounding wire to melt. Furthermore, these induced currents flowed into the tank, greatly increasing the temperature of tank _2-1 and bus 1. As described above, the conventional device has the disadvantage that a large induced current is generated in the closed circuit, which causes various troubles.

The present invention aims to provide a gas-insulated electrical device that eliminates such conventional drawbacks, and in particular, to obtain a closed circuit in which the induced current generated in the closed circuit constructed between the grounding network and the mount is small. , and is characterized in that the closed circuit formed by the tank, the frame, and the ground wire is formed in a "figure 8" shape.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 2 showing the first embodiment, it is connected to the grounding point 10 _-1 of the pedestal on one side, for example, pedestal 3 _-1 , and from there to the vicinity of the grounding point 10 _-2 of the pedestal 3 _-2 on the other side. In addition, the mount 3 _-2 on the other side is also connected to its grounding point 10 _-2 , and from there to the vicinity of the grounding point 10 _-1 of the mount 3 _-1 on the one side, each separately and mutually insulated. Grounding bars 11 and 12 are provided, and fittings 13 and 14 are provided at the tips of the grounding bars 11 and 12, respectively. Note that the grounding bars 11 and 12 are reinforced and insulated with insulators 15, 16, and 17, and the mounts _3-1 and _3-2 are not electrically connected to each other at locations other than the grounding points _10-1 and _10-2 . It is configured not to connect. Also, from each of the fixtures 13 and 14, a ground wire 1 is connected, respectively.
8 and 19 almost directly below, and their tips are connected to the main grounding wire 7 constituting the grounding network. The closed circuit including the pedestal and the main grounding wire of the present invention is configured in this way, thereby forming a "figure 8"-shaped closed circuit.

Note that the parts other than the above have the same configuration as the conventional device.

Since the present invention is configured in this way, the magnetic flux generated when current flows through the bus bar 1 is
Tank _2-1 , ground bars 11 and 12, ground wire 18
, 19 , and the closed circuit constituted by the main grounding line 7 , the voltages induced thereby are generated in the same direction along the axis of the tank 1 . Therefore, in the closed circuit in which an induced current is generated according to the present invention, since this closed circuit forms a "figure 8" shape, the induced voltage generated in the ground bars 11 and 12 _is The direction is opposite to the voltage induced in the main grounding wire 7, and therefore, in the closed circuit of the present invention forming a "figure 8" shape, the circulating current is canceled out, which is different from that in the conventional device. Its induced voltage is reduced compared to that of the circuit.

Furthermore, since the length of the circuit is increased, the impedance is increased, and therefore the induced current can be further reduced.

Next, the second embodiment will be described based on FIG. 3. One of the two grounding bars 11 and 12 in the first embodiment is provided on the other side of the pedestal, that is, at the back. That is, the ground bar 20
is provided behind the mounts 3 _-1 and 3 _-2 with respect to the ground bar 11, but in this case as well, it is composed of the tank 2 _-1 , the ground bars 11, 20, the main ground wire 7, etc. The closed circuit forms a "figure eight" shape. Note that the fixture 21, the grounding wire 22, and an insulator (not shown) are provided in the same manner as in the first embodiment.

With this configuration, in the second embodiment, the grounding bars are spaced apart from each other, resulting in a simpler structure and the effect that short circuits between the grounding bars are less likely to occur. It has in addition to the effects of the embodiment.

Further, in both the first embodiment and the second embodiment, there are two frames that support the tank 1, and two
However, in the third embodiment, the tank _2-1 is supported and grounded at four points, that is, four frames. That is, in FIG. 4, frames _3-3 and _3-4 are installed inside frames _3-1 and _3-2 of the first embodiment, respectively, and tank _2-1 is installed inside frames 3-1 _{and 3-4} . ,3
_-2 , _3-3 and _3-4 , and the grounding points _10-3 and _10-4 of pedestal _3-3 and _3-4 are also supported by pedestal _3-1.
and _3-2 .

In such a structure, as in the first embodiment, each grounding point 1 of the inner frames _3-3 and _3-4 is
0 _-3 and 10 _-4 respectively, and are provided with ground bars 30 and 31 extending from there to the other grounding point 10 _-4 or near 10 _-3 . As in the embodiment, fixtures 32 and 33 are provided, and grounding wires 34 and 35 are also provided.
is connected to this and placed directly below, and its tip is connected to the main grounding wire 7.

With this configuration, the induced pressure can be reduced in the third embodiment as well as the first embodiment, and even when there are four grounding points, the induced current can be similarly reduced.

Note that with this method, even when two or more electrically connected tanks are grounded at multiple points, it is possible to sufficiently reduce the induced voltage and reduce the induced current.

The present invention provides the following advantages when installing gas insulated electrical equipment:
Regardless of whether the grounding is done at two points or at multiple points, by configuring it in accordance with each of the above embodiments,
Current induced in the ground wire can be reduced.
Therefore, it is possible to prevent the ground wire from overheating and prevent it from burning out or melting down, and it is also possible to improve the safety of the exposed ground wire. In addition, although an induced current flows through the tank, this current can also be reduced, making it possible to suppress temperature increases in the tank and the bus bar.

Further, in the present invention, since the wiring of the ground wire to the ground network is conventional, the present invention can be applied even when a gas-insulated electrical device is installed in an existing ground network.

As described above, the present invention has great effects over a wide range of areas.

In each of the above embodiments, the gas insulated electrical device, and in particular the grounding method thereof, was explained.
Needless to say, all of these can be applied to gas-insulated busbars and gas-insulated switchgear.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional gas-insulated electric device, in particular, its grounding means; FIG. 2 is a perspective view of a first embodiment of the present invention; and FIGS. 2. It is a perspective view of the third embodiment. 1... bus bar, 2 _-1 , 2 _-2 ... tank, 3 _-1 , 3
_-2 , 3 _-3 , 3 _-4 ... Frame, 4 _-1 , 4 _-2 , 13, 1
4, 21, 32, 33...Mounting tool, 5, 6, 1
8, 19, 22, 34, 35...ground wire, 7...
Main grounding wire of the grounding network, 8...ground, 10 _-1 ,10
_-2 ,10 _-3 ,10 _-4 ...Grounding point, 11,12,
20, 30, 31...Ground bar, 15-17...
Insulator.

Claims (1)

[Scope of Claims] 1. In a gas-insulated electrical device in which one or more electrically connected tank stands are connected to a grounding network at two or more places, the tank, the stand, and the ground wire The closed circuit that is formed is
A gas insulated electrical device characterized by being formed in a "figure 8" shape. 2. Forming a closed circuit formed by the tank, pedestal, and grounding wire in a “figure eight” shape means that one end of each is connected to the grounding point of the pedestal on both sides of the tank, and from there, the closed circuit is connected to the grounding point of the pedestal on both sides of the tank. It is constructed by installing grounding bars that extend to the vicinity of the grounding point and electrically insulating each other, and providing grounding wires that are connected to the tips of each grounding bar and connected to the grounding network almost directly below. A gas insulated electrical device according to claim 1. 3. The gas insulated electrical device according to claim 2, wherein the grounding bars connected to the mounts on both sides are separately arranged in front and behind the mounts, respectively.