JPS6065415A - Buffer type gas breaker - 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] [Technical Field of the Invention 1] The present invention relates to a pant door-shaped gas 'a' which has an improved arc-extinguishing shape.
The present invention relates to circuit breakers, and particularly to a buffer type gas circuit breaker with an improved gas flow path for efficiently removing high-temperature gas remaining after arc extinguishment.

[Technical background of explanation] In recent years, with the increase in short-circuit capacity due to the increase in power transmission capacity, the number of visitors to circuit breakers has been steadily increasing. On the other hand, in order to downsize I-circuits, attempts are being made to increase the breaking capacity per point and reduce the number of series breaking points of the circuit breaker. Regarding the breaking performance of the circuit breaker, optimization of the electric field rise between the poles of the circuit breaker and gas blowing is required.

This point will be explained regarding the conventional buffer type gas circuit breaker shown in FIG. The figure shows the state in the middle of opening.

A cylindrical fixed electrode 1 and an annularly arranged movable electrode 2 are connected to an operating mechanism (not shown) on the right side of FIG. 1 by a hollow operating rod 3 having an opening 3a. A movable buffer cylinder 4 is mounted and fixed, and a compression chamber 6 is formed between the movable buffer cylinder 4 and a fixed buffer piston 5 having an opening 5a.

The buffer cylinder 4 is provided with an opening 4a, and an insulating nozzle 7a and an insulating cover 71) fixed to the buffer cylinder 4 pass through the cylindrical gas passage 8 into the compression chamber 6. The gas inside can flow in and out. These parts are housed in a container 9 made of an insulating material, and an internal space 10 of the insulating container 9 is filled with arc-extinguishing gas.

In this embodiment, the container is made of an insulating material, but a buffer type gas circuit breaker is also known in which the above-mentioned arc extinguishing chamber member is supported inside a metal tank by an insulating material and is configured as -C.

A disconnection command is given to this circuit breaker, an operation mechanism (not shown) is activated, and the operation rod 3 is driven to the right.
The movable electrode 2 connected to this operating rod 3 is the fixed electrode 1
When the state shown in the figure is released, an arc 1 is created between the small poles 1 and 2.
1 will occur. On the other hand, as a result of the movement of the operating rod 3, the movable buffer cylinder 4 attached to the operating rod 3 also moves to the right, compressing the arc-extinguishing gas in the compression chamber 6. This gas flows through the opening 4a1 of the buffer cylinder 4 through the gas flow path 8.
The waste is then blown into the arc 11 through the waste spouting port 8a, thereby erasing the arc 11. This gas stream is divided into two streams 12a and 12b, and the gas stream 12a, which is split to the left in FIG. 2, flows out into the surrounding space 10 through the opening 7C of the insulating nozzle 7a. The gas flow 12b split to the right side and the opening 7d of the insulating cover 7b and the opening 13 where the fixed electrode 1 left the movable electrode 2.
, opening 3a of the operating rod 3, fixed buffer screw i
・Flows out into the surrounding space 1o through the opening 5a of the tube 5.

[Problems with Background Art] In such a breaking operation, plasma gas that is positively and negatively ionized and gas heated to a higher temperature than the arc i remain behind after the arc is extinguished by the above-described mechanism. These plasmas and high-temperature gases have a high electrical conductivity and a low electrical dielectric strength, so after the arc is extinguished, a current flows between electrodes 1 and 2 due to the re-electromotive voltage applied between fliti1 and 2. It is easy to cause disconnection failure due to reasons such as electrical breakdown. Buffer-type gas circuit breakers are designed to remove residual plasma and high-temperature gas, which tend to cause circuit failures, from between the electrodes using the gas flow described above. Therefore, the breaking performance of the buffer type cass breaker is
It is determined by how efficiently the arc-forming gas can be sprayed between the electrodes.

However, when the blow NJ fiM structure shown in FIG. 1 is used, the gas flow 12a directed to the left in the figure is fixed type ti!
! 1 is the throw of the insulating nozzle 7a]-Before the part 7a-1 is removed, the gap 14 between the throat part 7a-1 of the insulating nozzle 7a and the fixed electrode 1 is as shown in FIG.
This means that it passes through the area and does not reach the vicinity of the tip of the fixed electrode. Therefore, the fixed electrode 1 is the slow I of the insulating nozzle 7a.
If the interrupting operation is performed at such a time that the current reaches zero point and the arc is extinguished before being pulled out from the part 7a-1, the plasma gas and high temperature gas 15 remaining near the tip of the fixed electrode 1 will be removed. The force cannot be eliminated and remains at one force near the tip of the fixed electrode. As a result, the electrical breakdown strength near the tip of the fixed electrode 1 also decreases due to the gas in other regions. For this reason, especially during BTF expansion, where dielectric breakdown due to the re-electromotive force applied between the extinguishing and restoring electrodes is a problem, the dielectric breakdown near the tip of the fixed N pole will cause re-ignition between the electrodes. , there was a risk that the shutdown would fail.

[Object of the Invention] The present invention has been made in view of the above problems, and aims to quickly remove plasma gas and high-temperature gas remaining near the tip of a fixed electrode after arc extinguishing from between the electrodes, and improve insulation recovery characteristics. It is an object of the present invention to provide a buffer type gas circuit breaker that can be realized.

"Summary of the Invention" The circuit breaker of the present invention has a throat part of the insulated nozzle that is relatively eccentric from the central axis of the fixed electrode, so that the area around the fixed electrode before the fixed electrode is pulled out from one part of the insulated nozzle throw is The gas flow is made asymmetrical with respect to the central axis of the fixed electrode,
As a result, a gas flow is generated near the tip of the fixed electrode,
The fixed type is designed to quickly remove plasma and high-temperature gas remaining near the tip of the fixed electrode from between the electrodes when the arc is extinguished before the fixed type is extracted from the insulated nozzle throat.

[Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIGS. 3 to 5. Note that parts that are the same as those in FIGS. 1 and 2 are designated by the same reference numerals 14, and description thereof will be omitted.

FIG. 3 shows the positional relationship between the fixed electrode and the insulated nozzle of a buff 1 type gas breaker showing an embodiment of the present invention.
is offset downward in the figure by a distance 111tD with respect to the central axis 16 of the fixed electrode 1. As a result, the throw section 7a-1 of the insulating nozzle 7a has a gap between it and the fixed electrode 1 (G1 on the upper side 14a in the figure and G2 on the lower side 14b, and there is a relationship of G2-G1=2D between them. holds true.

FIG. 4 shows the breadth type gas shield 1 according to the present invention! When the II device performs a cutoff operation, the fixed electrode 1 is connected to the insulated nozzle throw 1.
The state is shown when the current reaches zero point before the part 7a-1 is removed. As described above, plasma gas and high temperature gas 15 remain near the tip of fixed electrode 1. However, in this case, the throat portion 7a-1 of the insulating nozzle 7a and the fixed electrode 1 are 1! The l gap is the upper side 14a and the lower side 14b in the figure.
Since these are different, the flow rate of gas passing through each is different. Therefore, the gas flow 1 flows from the upper side 8a in the figure of the gas flow path 8 near the tip of the fixed electrode 1 and heads toward the gap 14b at the lower side in the figure.
8 will inevitably occur. As a result, the plasma gas and high-temperature debris 15 remaining near the tip of the fixed electrode 1 can be quickly removed from the vicinity of the tip of the fixed electrode by the gas flow 18 described above.

Here, in FIG. 4, if the radius of the fixed electrode 1 is 1゜ and the speed of movement of the movable part in the six-arc chamber is ■, then the volume of the space where the high temperature gas and plasma gas 15 exist is π per unit time.
r2v [] will increase.

On the other hand, from the diagram shown in Figure 5 and the cross-sectional view taken along section v-v in Figure 13,
Of the gap between the insulated nozzle throat portion 7a-1 and the fixed electrode 1 in FIG. 4, a portion 14b located below the fixed electrode 1 and a portion 14a located above the fixed electrode 1.
The difference in cross-sectional area between the two is 4Dr. In a normal buffer type gas circuit breaker, the pressure in the compression chamber 6 is sufficiently high during the circuit breaker operation, and it can generally be said that the gas flow velocity at the insulating nozzle throat portion 7a-1 is approximately equal to the speed of sound. Therefore, the difference between the gas flow rate passing below the fixed electrode 1 and the gas flow rate passing above the fixed electrode 1 per unit time is 4 Dra, where a is the speed of sound passing through the gas. This gas flow rate fj-4D r a
The gap 1 between the upper gas flow path 8a and the lower gas flow path 1 in FIG.
is the flow rate per unit time of the gas flow 18 towards 4b. Therefore, in order for the high temperature gas and plasma gas near the tip of the fixed electrode 1 to be removed by this gas flow 18, the following relationship must be established: yrr2v=4Dra. Equation (1) can be summarized as D π V (2) 4a The high temperature gas and plasma gas at the end are most efficiently removed and become If.

[Effects of the Invention] As described above, according to the present invention, the fixed electrode is fixed by making the gas flow rate around the fixed electrode non-uniform with respect to the central axis of the fixed electrode before the fixed electrode is released from a part of the insulated nozzle throw 1. Because it is possible to generate a gas flow that passes near the electrode tip, the plasma gas and It is possible to provide a buff 1 type gas circuit breaker that can quickly remove and cover high-temperature gas from between the electrodes and improve insulation recovery characteristics.

[Brief explanation of drawings]

Figure 1 is a partial cross-sectional view showing the operation of a conventional buffer type gas circuit breaker during the breaking operation, and Figure 2 is a cross-sectional view showing the flow of gas around the insulated nozzle and fixed electrode in Figure 1. 3 is an enlarged cross-sectional view of the vicinity of an insulated nozzle and a fixed electrode showing one embodiment of the present invention, and FIG. 4 is a diagram showing the operation of the buffer type gas shutoff device 11i during the shutoff operation according to the present invention. FIG. 5 is a partially sectional view of the insulated nozzle and the fixed electrode taken along the line V to V in FIG. DESCRIPTION OF SYMBOLS 1... Fixed electrode, 2... Movable electrode 1.4... Buffer sill, 5... Buffer piston, 6... Compression chamber, 7a... Insulating nozzle, 7b... Insulating cover,
8, 8a... Gas flow path, 11... Arc, 12a,
12b... Gas flow, 14.14a, 14b... Gap between fixed N pole and insulating nozzle, 15... Plasma gas and high temperature gas, 16... Central axis of fixed electrode, 17... Insulating nozzle Central axis of throat section, 18...Gas flow. Applicant's agent Patent attorney Takehiko Suzue /wJ V 10 12 Figure X 3a

Claims (2)

[Claims] (1) A cylindrical fixed electrode arranged about a common central axis and capable of moving toward and away from each other, a hollow movable electrode arranged opposite to this fixed electrode, and a circular sardine-shaped electrode arranged around the movable electrode. an insulated nozzle that forms a gas flow path and a gas ejection port into the movable electrode located around the central axis, and an opening to which the insulated nozzle is fixed and allows gas to flow in and out of the gas flow path. a movable buffer cylinder, a fixed buffer piston inserted into the buffer cylinder and configured to form a compression chamber between the buffer cylinders; The arc-extinguishing gas compressed in the compression chamber is blown against the generated arc through the opening of the movable buffer cylinder, the gas flow path, and the gas jet port, and the insulating nozzle is
! A buffer-type gas circuit breaker, characterized in that the hem portion is eccentric relative to the central axis of the cylindrical fixed electrode. (2) The radius of the cylindrical fixed electrode is 1゛, the eccentric distance between the central axis of the insulating nozzle throat and the central axis of the cylindrical fixed electrode is D1, the sound speed in the arc-extinguishing gas is a, and the moving part of the arc-extinguishing gas is 2. The buffer type gas circuit breaker according to claim 1, wherein when the average driving speed during the shutoff operation is V, the value of the ratio f IIL is approximately equal to the value of the ratio -.