JPS6057169B2 - Patshua type gas shield disconnector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buffer type gas cylinder, and more particularly to an insulated nozzle structure for controlling a flow of arc extinguishing gas to an arc generated during a cylinder braking operation.

Figure 1 is an explanatory diagram of the state in which the buffer type gas tank is turned on.
Stator 2... Mover 3... Shaft 5 of buffer cylinder 4... Flows to terminal 6. Then, an operating device (not shown) drives the buffer cylinder 4 in the right direction in the figure in response to the shearing command.
Braking action starts. Fig. 2 is an explanatory diagram showing a state in which the braking action is in progress. In this state, an arc 7 is generated between the movable element 3 of the stator 2, and the arc 7 is affected by the braking action. The flow of the compressed arc-extinguishing gas in the buffer chamber 8 is controlled by the insulating nozzle 9 to generate an arc.
and extinguish the arc 7. Therefore, the insulating nozzle 9 is an important factor in determining the shear cutting performance of the insulating nozzle 9, and various studies have been carried out heretofore.
FIG. 3 is a conventional configuration diagram of the insulating nozzle 9 shown in FIG.
Below, the results of conventional studies regarding the length LD of the flow guide section 9b on the downstream side of the throat section 9a of the nozzle 9 and the opening angle θ of the flow guide section 9b will be explained.

Figures 4 and 5 are representative diagrams of this.
ctofNo22leParametersonSF6
"Are Interruption" (IEEE71T7
These are the experimental results published in 2529-6). Figures 4 and 5 show the insulation recovery time TR until it can withstand a certain small current and a certain voltage. The vertical and horizontal axes indicate LD)θ and T, respectively.From Fig. 4, the longer the LD, the more T
It can be seen that R becomes shorter and therefore insulation recovery tends to become faster. Furthermore, from FIG. 5, it can be seen that there is an optimum value θ8 for θ at which TR is the shortest. Therefore, it has been shown that a nozzle with a strong dielectric strength has a long LD and a value of θ in the vicinity of 0 to θ8. In addition, according to the results of studies conducted by the inventors in the event of a large current shield break, it is easier to control the direction of the flow of high-temperature exhaust gas by increasing LO and not making θ too large, and the insulation between the electrodes Results have shown that it is effective in improving yield strength. However, in addition to the dielectric breakdown (D-BD) that occurs due to lack of dielectric strength as described above, the factors that determine the failure of a shield breaker include thermal breakdown determined by the energy balance immediately after the current shield breaks. It is well known that there is (T・BD). Typical examples of thermal damage include short-range line failures and disconnection failures. The results of the inventors' investigation into how LO and θ in FIG. 3 affect thermal breakdown are shown in FIGS. 6 and 7. Figure 6 shows
Figure 5 shows the results when the LD length of a nozzle with a value of θ close to θB is increased, and even though the shape is favorable in terms of dielectric strength, if the LO is made too long, , the shear limit determined by thermal breakdown tends to decrease. In addition, Fig. 7 shows the results of the study on θ, and the value of θ that provides the best shearing performance against thermal damage is θ.
, generally does not match θ8.

Note that the value of θ7 cannot be determined uniquely because it is dependent on the current value, but it seems certain that it will be a larger value than θB. As is clear from the above,
Nozzle structure factors that are excellent against dielectric breakdown and nozzle structure factors that are excellent against thermal breakdown generally do not match, and a nozzle structure that is excellent against both thermal breakdown and dielectric breakdown is required. The current situation is that

As mentioned above, the factors that determine the breaking performance of a shingle breaker are the dielectric breakdown and thermal breakdown characteristics of the insulating nozzle structure. At the stage where the extreme dimensions become large (at which point dielectric breakdown characteristics become a problem).

In other words, in the initial stage after the current is interrupted, the residual conductive part between the electrodes must quickly transform into a high-resistance material (arc-extinguishing gas) to deal with thermal damage. It is necessary to quickly remove the high-temperature gas between the electrodes and create an insulating nozzle structure that can withstand the high electric field strength applied to the tip of the stator without dielectric breakdown. As an improvement to insulated nozzles, it has been considered that the inner surface on the downstream side of the gas can suddenly change to a nearly right angle from the throat, and then have a gradual opening angle. If you do too much,
The gas flow does not become supersonic; on the contrary, a shock wave is generated in this part, and furthermore, downstream of it, the gas flow becomes subsonic.
There is a problem that the shearing characteristics cannot be improved.

In consideration of the above points, the present invention is an insulating nozzle in which the opening angle from the outlet of the throat section to the flow guide section is determined in order for thermal breakdown characteristics, and then for dielectric breakdown characteristics, and its purpose is to: It is an object of the present invention to provide a buffer type gas shield disconnector which can exhibit excellent insulation breakdown performance in terms of both the initial thermal breakdown characteristics of the current shield and the subsequent dielectric breakdown characteristics.

A feature of the present invention is that the opening angle of the flow guide section, which spreads out at a certain opening angle with respect to the flow path direction downstream from the throat section of the insulating nozzle, is adjusted so that the ring-shaped gas between the flow guide section and the stator At a position where the ratio of the cross-sectional area of the flow path to the cross-sectional area of the gas flow path of the throat portion is 1.5 to 3.0, change the angle so that the angle downstream from this position is smaller than the angle upstream, and heat and The purpose of this method is to improve both the dielectric breakdown properties and the insulation breakdown performance.

The present invention will be explained in detail below with reference to the embodiments shown in FIGS. 9 and 10 and FIG.

Similar to FIGS. 6 and 7, FIG. 8 shows that the vertical axis is the threshold current for thermal breakdown, and the gas flow path area of the throat portion 9a of the insulating nozzle 9 is expressed as the Atl flow guide portion 9b. When the cross-sectional area of the ring-shaped gas flow path between the stator 2 and the stator 2 is Ac (see Figure 2), α=Ac/At is taken as the horizontal axis, α
This is a diagram showing the experimental results of the relationship between Toshiya and the critical current -.According to this, α is a certain value α.

Below, the shearing limit current is extremely reduced. By the way, α. The value of αo is 1.5 to 3.0, although it varies depending on the buffer pressure and the shear current. What αo means is that in FIG. 2, stator 2 is α. At the point where the insulating nozzle 9 and stator 2
This is considered to indicate that the positional relationship between the two and Therefore, in the present invention, the insulating nozzle 9 is configured as shown in the embodiment shown in FIG.

In FIG. 9, the insulating nozzle 9 changes the opening angle θ of the flow guide portion 9b downstream from the throat portion 9a from θ1 to an angle 02 smaller than 01 at a certain position A. That is, in the positional relationship between the stator 2 and the insulating nozzle 9 (see FIG. 2), the above-mentioned α is α. Until reaching point A where
The downstream side of point A is the angle 02 which is smaller than 01, and the flow guide part 9b at the angle 02 is
The length LD2 in the flow path direction was determined to provide the required dielectric strength. In this case, as mentioned above, α
The opening angle is 0 from θ1 at point A where o=1.3 to 3.
However, if αo becomes too large, the gas blowing characteristics will deteriorate, and experiments have shown that a position in the range of αo = 1.3 to 3 is the best. If the insulated nozzle 9 with the configuration shown in FIG. 9 is used, at point A where an arc extinguishing effect effective against thermal breakdown occurs, θ=
The value of θT can be secured, and the arc extinguishing gas flow is sufficiently controlled by the opening angle θ2 and length LD2 of the flow guide section 9b downstream from point A, and the dielectric strength is also excellent. performance can be shown.

Therefore, it is possible to provide a buffer-type gas sheath disconnector that exhibits excellent shear breaker performance. FIG. 10 is a sectional view showing another embodiment of the insulating nozzle of the gas insulator and disconnector of the present invention.
In FIG. 10, the opening angle of the flow guide section 9b to point A is 0 in comparison with the rated voltage and the shear current.
1, 03 from point A to point B, and 02 downstream from point B.

However, it was arranged so that θ1>03>θ2. By doing so, there is a new effect that when the difference between θ1 and θ2 is too large, the direction control of the exhaust gas flow can be made even smoother. Other effects are similar to those in FIG. 9. As explained above, according to the present invention,
It has the remarkable effect of being able to exhibit excellent thermal breakdown characteristics at the initial stage of current shedding and dielectric breakdown properties thereafter.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a buffer type gas shield disconnector, Figure 1 is an explanatory diagram of a closed state, Figure 2 is an explanatory diagram of a shield disconnector, and Figure 3 is an illustration of a buffer type gas shield disconnector. A conventional configuration diagram of a nozzle, Fig. 4 is a diagram showing the relationship between the length LD of the flow guide part of the insulated nozzle and the insulation recovery time TR, and Fig. 5 is a diagram showing the relationship between the opening angle 0 and TR of the flow guide part of the insulated nozzle. The relationship diagram, Figure 6, is L. Figure 7 is a graph showing the relationship between θ and Figure 8 is α (=Ac/At).
Fig. 9 is a diagram showing the relationship between the insulation nozzle and the breaker limit current of the present invention;
FIG. 0 is a configuration diagram showing another embodiment of the insulating nozzle. 2
...Stator, 3...Movable element, 4...
... Buffer cylinder, 5 ... Shaft, 8
...Buffer chamber, 9...Insulation nozzle,
9a... Throat part, 9b... Flow guide part.

Claims (1)

[Claims] 1. A stator, a mover in contact with the stator, a puffer chamber that compresses arc-extinguishing gas, a throat portion into which the stator is inserted, and a flow guide portion formed on the downstream side of the throat portion. and an insulating nozzle that guides and blows the compressed arc-extinguishing gas to the arc generated when the stator and mover break, and the opening angle of the flow guide portion of the insulating nozzle in which the opening angle of the flow guide portion of the insulating nozzle changes from the throat portion to the downstream side, the opening angle of the flow guide portion of the insulating nozzle is determined by the gas flow of the throat portion relative to the cross-sectional area of the link-shaped gas flow path between the flow guide portion and the stator. A puffer-type gas sheath disconnector characterized in that at a position where the ratio of road cross-sectional areas is 1.5 to 3.0, the angle on the downstream side of the position is smaller than the angle on the upstream side.