JPS6334686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas insulated bus bar, and more particularly to a grounding system for a gas insulated bus bar.

To explain the conventional grounding method for gas-insulated busbars,
As shown in Fig. 1, both ends of the tank containing the current-carrying conductors of the gas insulated busbars 1 and 2 and the insulating gas are connected to other phase tanks by conductive bars, that is, shorting bars 3 and 4, to support the tank. The frames 5 and 6 are connected via rising ground points 7 and 8 to a main ground line 9 that is part of a ground network buried underground.

In such a configuration, when the bus current directions of the gas insulated buses 1 and 2 are in different directions, most of the induced current flows between the tank 2 - the shorting bar 4 - the tank 2 of the other phase - the other shorting bar 4, or , Tank 1-Short bar 3-
Flows into the tank 1-other short bar 3 circuit of the other phase,
The main grounding wire 9a between the gas insulated busbars 1 and 2 includes:
Almost no induced current due to the bus current flows, and much of it flows through the shorting bars 3 and 4. However, when the bus current directions are in the same direction, most of the induced current is from the main grounding wire 9a - the rising grounding wire 7 - the tank 1 - the shorting bar 3 - the tank 1 of the other phase - the rising grounding wire 7 of the other phase. Main grounding wire 9a of other phase - rising grounding wire 8 of other phase - tank 2 of other phase - shorting bar 4 - tank 2
- The induced current flowing in the circuit of the rising ground wire 8 and the shorting bar on the opposing gas insulated bus side is small, and the induced current between the rising ground wires 7 and 8 on the opposing gas insulated bus side and the gas insulated bus bar is small. Ground wire 9
Most of it flows into a. For this reason, the ground wire heats up and is dangerous at exposed parts, and also has drawbacks such as causing the ground wire to melt.

The present invention relates to a gas insulated bus bar, and was made in particular in view of the above-mentioned drawbacks of the conventional grounding system for gas-insulated bus bars.It is an object of the present invention to provide a gas-insulated bus bar equipped with a grounding device that eliminates the above-mentioned drawbacks. It is an object.

In order to achieve the above object, the present invention provides a gas insulated bus bar characterized in that the main grounding wire between two gas insulated bus tanks is connected at one point for three phases. .

The present invention will be explained below based on the illustrated embodiments. As shown in FIG. 2, in the present invention, the main grounding wires 9 of each phase are connected by a main grounding wire 10, and the gas insulated buses 1 and 2 are connected by a main grounding wire 11 that is combined into one. Except for the connection of the ground wire, the embodiment shown in FIG. 2 is almost the same as that shown in FIG.

By doing this, most of the induced current is transferred between tank 2 - shorting bar 4 - tank 2 of another phase - other shorting bar 4, or tank 1 - shorting bar 3 -
Flows into the tank 1-other short bar 3 circuit of the other phase,
The gas insulated bus bars 1 and 2 are electrically connected by the main ground wire 11, but since there is only one main ground wire, a closed loop including both the gas insulated bus bars 1 and 2 is connected to the gas insulated bus bar 1. , 2 and the external grounding network installed therein, the impedance increases and the induced current flowing through the main grounding wire 11 decreases. Although not shown, a gas circuit breaker may be installed between the gas insulated bus bars 1 and 2.

As described above, according to the present invention, since the current flowing through the ground wire can be reduced, overheating of the ground wire can be prevented, the safety of exposed ground wires can be improved, and melting of the ground wire due to overheating can be prevented. There is.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional gas insulated bus bar, and FIG. 2 is a perspective view showing an embodiment of the gas insulated bus bar of the present invention. 1... Gas insulated bus bar; 2... Gas insulated bus bar; 3
... Short circuit bar; 4 ... Short circuit bar; 5 ... Frame; 6
... Frame; 7... Standing ground wire; 8... Standing ground wire; 9, 9a... Main ground wire; 10...
Main grounding wire; 11...Main grounding wire.

Claims (1)

[Claims] 1 Multiple tanks containing current-carrying conductors and insulating gas are arranged in parallel with different phases, and multiple tanks are installed in the axial direction, and both ends of the tanks are electrically connected by conductive bars across the phases. A gas insulated bus of a phase-separated type, characterized in that a main grounding wire between the two tanks connects three phases at one point.