JPS6259523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to reduce the current induced in the grounding wire in gas-insulated electrical equipment such as gas-insulated busbars, and to prevent problems caused by temperature rises in the grounding wire. be. For convenience, typical gas-insulated busbars will be described below.

A conventional gas insulated bus bar was constructed as shown in FIGS. 1 and 2. FIG. 1 is a plan view of the gas insulated bus bar, and FIG. 2 is a front view. In these figures, 4 is a metal tank filled with insulating gas;
A main conductor 5 for energization is housed in this.
6 is a frame for supporting the tank. The grounding wires 1 and 2 are connected to the pedestal 6 or the tank 4,
It is buried underground. The tanks of each phase are short-circuited by a short-circuit bar 3 to allow a sheath current to flow. The grounding wires 1 and 2 are grounded at multiple points for protection against surges, and are installed underground in the form of a net. In particular, the grounding wire 1 is arranged outside the shorting bar 3 to connect the frames of each phase. Note that 7 is bushing and 8 is ground.

In such a configuration, when current flows through the main conductor, sheath current 11 flows through the tank 4 and shorting bar 3 of each phase. At this time, since the current flowing in the main conductor is not completely suppressed by the sheath current, induced currents 9 and 10 also flow in the ground wire. Of these, the induced current 10 becomes particularly large because the magnetic flux leaking to the outside of the shorting bar 3 is not suppressed. Conventionally, this induced current poses a risk of causing problems such as burnout and melting of the grounding wire. It was hot.

The present invention was made in order to eliminate the above-mentioned drawbacks, and the grounding wire connecting the grounding wires of each phase, which are arranged in parallel to the metal tanks of each phase, is connected vertically to the shorting bar. By providing it between the projection lines, the purpose is to reduce the induced current flowing in the ground wire and protect the ground wire.

Hereinafter, one embodiment of the present invention is shown in FIG. 3 (plan view) and FIG. 4 (front view).
This will be explained in comparison with FIG.

3 and 4 show an embodiment of the present invention, the basic structure of which is the same as the conventional type described above. The difference from the conventional method is that instead of lowering the grounding wire 1 from the pedestal 6 into the ground and connecting the phases directly from there, the grounding wire 1 is placed inside the line obtained by vertically projecting the shorting bar 3, that is, at the center. To the side, pedestal 6
It was pulled from the ground, lowered into the ground, and connected between the two. By this, the grounding wire 1
The induced current 10 is reduced because it enters the inside of the circuit formed by the sheath current flowing through the shorting bar 3 and is shielded. On the other hand, the induced current 9 hardly changes because the sheath current value does not change due to such a change in the grounding wire 1.

This effect is the same in other embodiments shown in FIG. 5 (plan view) and FIG. 6 (front view). In this case, as shown in FIG. 6, the grounding wire 1 is lowered from the pedestal 6 into the ground, and from there it is pulled laterally to the inside of the vertical projection line of the shorting bar 3, and connected to the grounding wire 2.
Furthermore, it connects the phases. In other embodiments shown in Fig. 7 (plan view) and Fig. 8 (front view), the grounding wire 1 is lowered into the ground from the bottom of the tank inside the shorting bar 3, and connected to the grounding wire 2 there. , further connects the phases, and similarly, the induced current 1
0 can be reduced. Furthermore, in another embodiment shown in FIGS. 9 and 10, the shorting bar 3 is connected to the tank of the bushing and pulled out from there to short-circuit the phases without changing the position of the grounding wire. In this case as well, the grounding wire 1 is weakened by the sheath current flowing through the shorting bar 3, and the induced current 10
is reduced.

Note that the present invention is similarly applicable to gas insulated busbars installed in underground concrete trenches, gas insulated busbars whose tanks are not arranged in a straight line, and gas insulated switchgear.

As described above, according to the present invention, it is possible to reduce the current induced in the grounding wire and prevent troubles due to temperature rise in the grounding wire.

[Brief explanation of the drawing]

1 and 2 are a plan view and a front view showing a typical structure of a conventional gas-insulated bus bar, and FIGS. 3 and 4 are a plan view, a front view, and a front view showing an embodiment of the present invention. 5
FIG. 6 is a plan view showing another embodiment of the present invention,
A front view, FIGS. 7 and 8 are plan views and front views showing still other embodiments of the present invention, and FIGS. 9 and 17 are plan views and front views showing still other embodiments of the present invention. It is. Note that the same reference numerals in the figures indicate the same or corresponding parts. In the figure, 1... Ground wire, 2... Ground wire, 3... Short circuit bar, 4... Tank, 5... Main conductor (current carrying conductor), 6... Mount, 7... Bushing, 8... Ground , 9... Induced current, 10... Induced current, 11...
...sheath current.

Claims (1)

[Claims] 1 A metal tank filled with an insulating gas containing a current-carrying conductor is provided for multiple phases, and a shorting bar is provided to connect the metal tanks, and a sheathed current path is established by the metal tank and the shorting bar. In the gas-insulated electrical equipment, a grounding wire that connects the grounding wires of each phase, which are arranged parallel to the metal tanks of each phase, is provided between the vertical projection lines of the shorting bar. A gas insulated electrical device featuring: