JPS59201616A - Gas insulated electric device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to gas-insulated electrical equipment such as gas circuit breakers and gas-insulated switchgears, and particularly to a structure for preventing foreign matter from entering the sealed container thereof.

[Background of the invention]

FIG. 1 shows an SF6 gas system diagram of a conventional gas circuit breaker.

The sealed containers 1, 2.3 are first evacuated and then filled with several atmospheres of SF6 gas. The sealed containers 1, 2.3 are evacuated and filled with SF6 gas in the following steps. In the case of evacuation, the valves 4.5, 6, 12.13 are opened and the valve 14 is closed, and then the vacuum pump 15 is operated to evacuate the inside of the sealed container 1.degree. 2.3. After creating a vacuum inside the sealed container, close the valve 13, open valves 4, 5, 6, 12 and 14, and inject SF6 gas into the sealed containers 1, 2.3 at several atmospheres through the SF6 gas filling device 16. Fill. When filling is completed, close the valve 11, remove the 7-lunge 12, and install the closing 7-lunge 9 instead. 1.2.3 When vacuuming and gas filling each container, the valves 4, 5, and 6 arranged for each container are opened and closed as desired. Conductor parts such as movable contacts and fixed contacts, which are the main parts of the circuit breaker, are arranged inside the filled container.

In gas-insulated electric equipment configured in this manner, it is necessary to prevent foreign matter, particularly conductive foreign matter, from entering the sealed container. However, in the past, research and development has been progressing on particle traps that remove mixed foreign matter, rather than preventing conductive foreign matter from forming tails themselves.

However, the present inventors considered preventing the contamination of foreign matter itself. Even if such an attempt cannot completely prevent foreign matter from getting mixed in, it can impose limits on the amount of foreign matter that gets mixed in.

[Purpose of the invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas-insulated electric device that prevents or restricts the ingress of foreign objects.

[Summary of the invention]

According to the experiments and studies conducted by the present inventors, it has been determined that the main cause of foreign matter contamination is through the threaded and sliding parts of piping and valves. That is, these piping and valves are not manufactured as special parts for gas insulated electrical equipment, but are manufactured as general-purpose products.

Therefore, the management of cuticles and the like is slow from the perspective of gas-insulated electrical equipment. According to these findings, even if gas-insulated electrical equipment is manufactured with high reliability, its reliability is reduced by the gas supply and exhaust system.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings.

According to FIG. 3 showing an embodiment of the present invention, SF6 gas flows into the sealed container 1 from the pipe 22 through the filter 24 during filling. Foreign matter present in the pipes and valves together with the SFg gas is prevented from entering the sealed container 1 by the filter 24. In this embodiment, when only relatively large foreign objects are to be prevented and the inside of the sealed container is evacuated, there is no large change in conductance when air is discharged compared to the conventional structure shown in Fig. 2. This is effective only if there is no problem with the time required to reach vacuum. If you want to prevent relatively small foreign matter from entering the sealed container, you will need a fine-mesh filter, so of course the structure shown in Figure 3 is better than the conventional structure shown in Figure 2 when creating a vacuum inside the sealed container. Compared to this, the conductance is small, and the time required to reach a vacuum is longer.

For this reason, when the purpose is to prevent the incorporation of relatively small foreign matter, a structure is required that does not cause the disadvantage that when creating a vacuum in the sealed container, the conductance becomes small due to the filter and the time required to reach the vacuum becomes longer. The following embodiments will be described using FIGS. 4 and 5 as examples.

When creating a vacuum inside the sealed container 1, the switching valve 25 is moved to the left as shown in FIG. At this time, the valve body 30 and the body 27
The valve seat of is opened. In this case, when vacuuming, the air inside the sealed container 1 passes between the valve body 3o and the valve seat of the body 27, and the air enters the pipe 22.
flows out to. A part of the air is passed from the sealed container to the filter 31
It flows out to the through pipe 22, but the valve body 30 and the body 27
Most of the air in the sealed container is opened between the valve seats of the valve element 30 and the valve seat of the body 27, and flows out into the pipe 22. Therefore, there is no decrease in conductance, and there are no problems such as an increase in the time required to reach vacuum.

Next, when filling SFsF2 gas into the sealed container, the switching valve 25 is moved to the right as shown in FIG. The valve body 30 is sealed to the valve seat of the body 27 and receives SF supplied from the piping 22 side.
6 gas flows into the sealed container through the filter 31. As a result, piping 17°18.22 and gas valves 4 and 5
, 6, 11, 13, and 14 are blocked by the filter 31, and therefore do not enter the sealed container. Here, when the switching valve 25 moves to the right and left, it is held in the opposite position by the position holding device 26, and its operating position will not become unstable due to the pressure of the SF6 gas inserted into the sealed container. .

Further, the switching valve 25 is located between the filter 31 and the atmosphere side, and foreign matter generated by the sliding of the switching valve itself can be prevented by the filter 31 and will not be mixed into the sealed container. According to this embodiment, it is possible to prevent foreign matter from entering the sealed container and provide a highly reliable device.

Next, the embodiments shown in FIGS. 6 and 7 will be described.

When creating a vacuum inside the sealed container l, connect joint 3 as shown in Figure 7.
3 to position the pipe 22 downward. At this time, the filter 37 is positioned as shown in FIG. 7 due to free fall. Therefore, the air in the sealed container 1 does not pass through the filter 37 but flows out through the ventilation hole of the flange 32 into the pipe 22. Next, when filling with SF6 gas, the joint 33 is rotated to position the pipe 22 upward. At this time, the filter 37 is positioned as shown in FIG. 6 due to free fall. Therefore, the pipe 22
SF6 gas supplied from the side flows from the flange 320 vent hole through the flange vent hole 37 into the sealed container. From the above, the filter 37 can prevent foreign matter from entering the sealed container when the SF6 gas flows in. Furthermore, when the inside of the sealed container is evacuated, the air inside the sealed container is exhausted without passing through the filter 37, so there is no reduction in conductance and there are no problems such as a longer time to reach vacuum. According to this embodiment, as with the embodiments shown in FIGS. 4 and 5, it is possible to prevent foreign matter from entering the sealed container, and a highly reliable device can be provided.

Next, the embodiments shown in FIGS. 8 and 9 will be described. This embodiment is used when the inside of the sealed container 1 is evacuated or when SF6
This method focuses on the fact that when gas is filled, a pressure difference is created between the pressure inside the sealed container 1 and the pressure inside the pipe 22. FIG. 9 shows a cross-sectional view of the main part when the inside of the sealed container is evacuated. The inside of the sealed container is at atmospheric pressure, and the pipe 22 is connected to the vacuum pump 15.
It is connected to the. Filter 39 is normally located as shown in FIG. When the vacuum pump is operated here, the pipe 22
As the pressure on the side becomes smaller than the pressure inside the sealed container, the pressure difference becomes stronger than the force of the spring 40, and the filter 39 connected to the spring 40 moves as shown in FIG. Therefore, the air in the sealed container does not pass through the filter 39, but flows out into the pipe 22 through the ventilation hole in the flange 42. When filling SFsF2 gas after evacuating the sealed container, use piping 2.
Since the pressure is greater than that on the second side, the filter 39 moves as shown in FIG. Therefore, the SFa gas supplied from the pipe 22 side passes through the filter 39 and flows into the sealed container. From the above, it is possible to prevent foreign matter from entering the sealed container, similar to the embodiment described above.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to investigate the cause of foreign matter entering the sealed container of a gas circuit breaker and gas insulated switchgear,
By taking such measures, highly reliable gas-insulated electrical equipment can be provided.

Fig. 1 is a diagram of the SF6 gas system of the gas circuit breaker, Fig. 2 is a cross-sectional view of the main parts of the conventional SF6 gas intake and discharge into a sealed container, Fig. 3
9 through 9 are sectional views of essential parts showing four different embodiments of the present invention.

1... Sealed container, 4... Valve, 17... Piping, 2
2...I intentional 2 z fragile32 plan 6 intentional 8 mouth

Claims (1)

[Claims] 1. In gas insulated electrical equipment, where the sealed container is filled with SFa gas through a valve and piping, a filter is provided between the sealed container and the valve, and this filter prevents foreign matter from entering the sealed container. Characteristic gas insulated electrical equipment.