JPH0247544Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention relates to gas shields and disconnectors, and in particular, a puffer-type gas L with improved current shielding and disconnection performance.
It concerns spear breakers.

[Prior art]

To explain an example of a conventional gas cutter,
As shown in the figure, the arc extinguishing chamber portion 1 includes a pair of arc contacts that move toward and away from each other, namely a fixed arc contact 2, a movable arc contact 3, and a flow guide 4 for spraying arc extinguishing gas to the arc. It is structured accordingly. Normally, in a single-pressure gas discharger or disconnector, the arc extinguishing chamber portion 1 is attached to one end of a puffer cylinder 7 that forms a compression chamber 6 together with a piston 5, and the discharge is discharged from this compression chamber. Arc extinguishing gas is used to extinguish the arc by spraying it onto the arc through a flow guide. A gas outlet 8 is provided at the end of the compression chamber of the puffer cylinder 7, which leads the gas into the flow guide. In addition, energization at the closed position of the breaker is carried out by the fixed main contact 10 and the movable main contact 11. Furthermore, an energization path is formed from the puffer cylinder 7 through the slide contact 12, and the movable Electricity is established between the side terminal 13 and the fixed side terminal 14. In addition, in a shield breaker having a multi-point disconnection configuration in which a plurality of shield sections are connected in series, a voltage dividing capacitor 17 is set in parallel with the shield sections. This is to control so as to equalize the voltage distribution between the insulation parts. On the other hand, in order to withstand the voltage that appears between the electrodes in the open state, it is necessary to limit the electric field strength on the surface of each electrode to a value that is not too high.
will be provided.

In such a configuration, the movable main contactor 11
The shield 15 that protects the main contact 10 needs to be installed far forward, that is, in a manner that protrudes toward the fixed main contact 10. This imposes restrictions such as reducing the distance between the shields, and the structure There were also many disadvantages. In particular, the above-mentioned restrictions regarding the installation position of the voltage dividing capacitor 17 were the most important. That is, on the voltage dividing capacitor 17, the potential is uniformly distributed over the entire length due to the approximately uniform electric field gradient. However, because the shield 15 protrudes forward, the equipotential line (surface) near the shield is connected to the voltage dividing capacitor 1.
It is pulled to the bottom of 7 (in the figure). Therefore, the electric field strength on the surface of the shield 15 becomes extremely large. In order to avoid this, it was necessary to provide an appropriate distance between the shield 15 and the voltage dividing capacitor 17. A further disadvantage of this configuration is that the shield 15 prevents the movable main contact 11 from being close to the shield 15.
The electric field between the movable main contact 11 and the movable arc contact 3 is relaxed.
Since there is a large distance from the outer diameter of the arc contactor, the electric field on the surface of the arc contactor cannot be expected to have an electric field mitigation effect by the movable main contactor 11. All of these shortcomings have created limitations for raising the voltage of conventional shunt-cut units.

[Summary of the idea]

This idea was made in view of these drawbacks of the single pressure compressor and disconnector. An electric field relaxation electrode having a large radius of curvature is provided on the outer circumferential side located inside the arranged shield, and the end of the electric field relaxation electrode close to the other arc contactor is located at the end of one arc contactor located in the flow guide. It is an object of the present invention to provide a gas shield and disconnector having a high unit voltage, by locating it closer to the other arc contact than the other end.

[Example of idea]

This invention will be explained below based on the illustrated embodiments. As shown in FIG. 2, the gas shield and disconnector of this invention is provided with an electric field relaxation electrode 18 having a large radius of curvature for relaxing the electric field at a position surrounding the flow guide 4, and a movable main contactor 11. Except for the point that it is placed on the outer periphery, its configuration is almost the same as that of the conventional one shown in FIG.
A description of its constituent effects will be omitted. However, the shield 15' is provided rearward (downward in the figure) from the shield 15 in FIG. Electric field relaxation electrode 18
The inner diameter of the movable arc contactor 3 is made 2.5 times the outer diameter of the movable arc contactor 3.

The extinguishing operation is the same as the conventional one, and the arc extinguishing gas discharged from the gas compression chamber 6 is guided by the flow guide 4 to the arc generated between the two arc contacts 2 and 3 that are being opened. It is something that makes a decision.

The operation of this invention will be explained next. By providing the electric field relaxation electrode 18 and making the inner diameter of this electrode 2.5 times or less than the outer diameter of the movable arc contact 3, the relaxation effect of the electric field relaxation electrode 18 extends to the position of the movable arc contact 3. That is, the entry of equipotential lines (surfaces) between the movable arc contactor 3 and the electric field relaxation electrode 18 is suppressed, and the electric field strength at the tip of the movable arc contactor 3 is kept low. In particular, this effect is enhanced by locating the tip of the electric field relaxation electrode 18 in front of the tip of the movable arc contact 3. Also,
Since this electric field relaxation electrode 18 is formed with a gentle curvature, it can itself maintain a low surface electric field. For this reason, even when the shield 15' is provided on the outside thereof, it does not need to protrude in the axial direction, and can be designed only to protect the slide contact 12 from an electric field. As a result, it is also possible to reduce the field strength of the strong electric field generated in the shield 15' due to potential regulation by the voltage dividing capacitor 17. Note that the inner diameter of the electric field relaxation electrode 18 is equal to the outer diameter of the movable arc contactor 3.
When it is 2.5 times or more, the effect of electric field relaxation is weakened. To compensate for this, it is possible to extend the electric field relaxation electrode toward the fixed contact, but in this case,
The electric field strength of the electric field relaxation electrode itself increases, and this portion becomes an electrical weak point. Therefore, the inner diameter of the electric field relaxation electrode is less than 2.5 times that of the movable arc contact. To explain this electric field relaxation effect in more detail, Figures 5a and 5b show equipotential diagrams when +100% and -100% power is applied to the movable electrode and the fixed electrode, respectively, in a conventional arc extinguishing chamber. The electric field strength distribution map on the electrode surface (the length of the arrow is proportional to the electric field strength) is
Further, FIGS. 4a and 4b show equipotential diagrams and electric field strength distribution diagrams in the arc extinguishing chamber according to the present invention. Comparing the equipotential diagrams in FIG. 5 for the conventional example and FIG. 4 for the present invention, in the case of the present invention shown in FIG. It is located closer to the fixed arc contact 2,
As a result, equipotential lines near the movable arc contact 3 that are located inside the electric field relaxation electrode 18 and outside the movable arc contact 3 are located higher in the diagram compared to the conventional example in FIG. 5a. . Therefore, the electric field strength on the surface of the movable arc contactor 3 of the present invention is lower than that of the conventional example shown in FIG. 5b, as shown in FIG. 4b.

Here, the length of the arrows in FIGS. 4b and 5b is proportional to the electric field strength. The above effect is called an electric field relaxation effect. Note that this electric field relaxation effect is caused by the fact that when the inner diameter increases even if the vertical position of the electric field relaxation electrode is the same in the figure, the equipotential line located inside the electric field relaxation electrode and outside of the movable arc contact 3 mentioned earlier becomes As it falls downward in the figure, the electric field relaxation effect decreases. The electric field relaxation electrode 18 has ribs (not shown) at several locations on the outer peripheral surface of the movable arc contactor 3.
It is fixed via.

In the embodiment shown in FIG. 2 above, the flow guide is provided on the movable side, so the electric field relaxation electrode is provided on the outside of the flow guide, that is, on the movable side. However, in the embodiment shown in FIG. As in the example, when the flow guide 4 is provided on the fixed side, this electric field relaxation electrode 18 is provided on the fixed side. In this case, the parts that constitute the gas compression chamber 6 are the piston 5 and its cylinder 19, and the cylinder 19 is made of an insulator. The cylinder 19 and the piston 5 are driven in the axial direction together with the movable arc contactor 3. In this case as well, the electric field relaxation electrode 18 relaxes the electric field in the fixed arc contactor 2 portion, and the shield 1
5' to the rear.

[Effect of idea]

As described above, according to this invention, the entry of equipotential lines between the movable arc contact and the electric field relaxation electrode is suppressed, the electric field strength at the tip of the movable arc contact is kept low, and the electric field relaxation electrode itself is The surface electric field strength can be kept low, and the outer diameter of the voltage dividing capacitor and the height of the shield can also be reduced. As a result, it is possible to limit the surface electric field strength to a low level even when the applied voltage is high, so that the unit voltage can be increased and the breaker can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional single-pressure puffer-type gas shield and disconnector in its open position;
FIG. 2 is a cross-sectional view showing an embodiment of the single-pressure puffer-type gas shield and disconnector according to this invention at the open position;
FIG. 3 is a sectional view similar to FIG. 2 of another embodiment, FIG. 4 is an explanatory view for explaining the device of the present invention, and FIG.
The figure is an explanatory diagram for explaining a conventional device. 1... Arc extinguishing chamber part, 2... Fixed arc contactor,
3...Movable arc contactor, 4...Flow guide,
5... Piston, 6... Gas compression chamber, 7... Puff cylinder, 8... Discharge port, 10... Fixed main contact, 11... Movable main contact, 12... Slide contact, 13... Movable Side terminal, 15, 15', 1
6...Shield, 17...Division capacitor, 18
...Electric field relaxation electrode, 19...Cylinder.

Claims (1)

[Scope of utility model registration request] a pair of arc contacts that can be relatively separated; a puffer cylinder that forms a compression chamber for compressing arc-extinguishing gas; a flow guide that guides the arc-extinguishing gas discharged from the compression chamber toward the arc; a shield located on the one arc contact side and arranged around the outer periphery of the puffer cylinder; A voltage dividing capacitor installed in parallel between the terminals,
In a puffer-type gas shield and breaker comprising an electric field relaxation electrode that is concentrically close to the outer periphery of the flow guide, is smaller than the inner diameter of the shield, and is arranged so as to surround the outer periphery of one of the arc contacts. , the electric field relaxation electrode has a shape having a large radius of curvature on the outer circumferential side so that the electric field relaxation effect extends to the one arc contactor, and the end of the electric field relaxation electrode has a shape that extends to the one arc contactor. A puffer type gas shield breaker characterized by being located closer to the other arc contact than the end.