JPH02117043A - Buffer type gas breaker - Google Patents

Abstract

PURPOSE:To contrive to improve the characteristics of leading small current by connecting two arc extinguishing chambers in series, which are different in buffer chamber diameter, and thereby making voltage burden on the side of the arc extinguishing chamber great, in which leading small current characteristics are excellent. CONSTITUTION:A buffer cylinder 6a on the side of an arc extinguishing chamber 2a is smaller in diameter than a buffer cylinder 6b on the side of an arc extinguishing chamber 26, and link mechanism sections 16a and 16b on the arc extinguishing chamber 2a side is larger in link ratio than ones on the arc extinguishing chamber 2b side. Namely, the stroke on the arc extinguishing chamber 2a side is langer than that on the arc extinguishing chamber 2b side so that the contact parting speed of the former is designed to be higher than that of the latter. In addition, a capacitor cylinder 14a on the arc extinguishing chamber 2a side is made smaller in electrostatic capacity than a capacitor 14b on the arc extinguishing chamber side 2b side so that its voltage burden is made great. This constitution thereby improves the current breaking characteristics of leading small current.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a buffer type gas circuit breaker that compresses gas by the movement of a moving part to create a gas flow to cool and interrupt an arc when current is interrupted. Particularly advanced and improved small current interrupting characteristics 2
This article relates to the structure of a cut-off gas circuit breaker.

(Prior Art) Conventionally, when increasing the rated voltage of a circuit breaker, there is a limit to the withstand voltage value per one breaking point, so a multi-point breaking structure is usually used. In the multi-cut structure, a capacitor tube is installed in parallel between each pole to equalize the voltage sharing between each breaking point and to support the arc extinguishing chamber. FIG. 2 shows the inside of a conventional circuit breaker arc extinguishing chamber.

In the grounded tank 21, arc extinguishing chambers 24a and 24b having built-in cut-off parts at both ends of the joint case 23 are housed together with an insulating gas 22 such as SF or gas. Both arc extinguishing chambers 24a, 2
Bushings 26 from both sides of the fixed contact 25 of 4b.
a.

Conductors 27a and 27b are led to the outside via 26b. The movable contacts 28 of the arc extinguishing chambers 24a and 24b are connected to a link mechanism section 29 within the joint case 23 and supported by a supporting insulating cylinder 30. This link mechanism part 29 is connected to an operating device (not shown) and an insulating rod 3 provided in a supporting insulating cylinder 30.
Connected and driven via 1.

(Problems to be Solved by the Invention) In the circuit breaker as described above, it is necessary to satisfy both of the heavy current interrupting duties. Particularly in recent years, as the number of breaking points of circuit breakers has decreased, the rated voltage per breaking point has increased, and the responsibility for breaking small currents has become more severe. This advanced small current interruption duty is 2 times higher than the voltage before interruption after the current is interrupted.
This is because double the voltage is applied between the circuit breaker poles. Furthermore, as power transmission capacity increases, the breaking capacity of circuit breakers has also increased. For this reason, in order to improve the breaking performance of conventional buffer type gas circuit breakers, a large buffer cylinder is moved at a high opening speed to make the gas in the buffer chamber high pressure and spray it onto the arc. When such a large buffer cylinder is used and operated at a high opening speed, the gas flow becomes high speed and the gas pressure decreases along the nozzle surface. As a result, under conditions where the current is small, such as when the current is required to cut off a small amount of current, it is possible to cut off even with a short contact opening distance, and then a high voltage appears between the poles, which may lead to re-ignition.

An object of the present invention is to provide a two-point buffer type gas circuit breaker that does not cause re-ignition when the two-point buffer type gas circuit breaker advances and interrupts a small current.

[Structure of the invention]

(Means for Solving the Problem) In order to achieve the above object, in the present invention, an arc extinguishing chamber with a large cylinder diameter and an arc extinguishing chamber with a small cylinder diameter are connected in series,
A capacitor cylinder is connected in parallel with both of the extinguishing chambers, and the arc extinguishing chamber with a small cylinder diameter has a faster opening speed and longer stroke length than the arc extinguishing chamber with a larger cylinder diameter. The capacitance of a capacitor cylinder installed in a small arc extinguishing chamber is made smaller than that on the arc extinguishing chamber side where the cylinder diameter is large.

(Function) The voltage appearing on the arc extinguishing chamber side, which has good advanced small current interrupting characteristics, is increased to improve the advanced small current interrupting characteristics.

(Example) An example of the present invention will be described below with reference to FIG. In FIG. 1, arc extinguishing chambers 2a and 2b are housed in a container 1 filled with an arc extinguishing gas such as SF gas. 3a.

3b is a movable contact portion, and 4a and 4b are fixed contact portions.

Possible tJj contactor parts 3a, 3b are operating rods 5a, 5b
Buffer cylinders 6a, 6b, and current-carrying contact 7a are provided on the flange portions.

7b, arc contacts 8a, 8b, and nozzles 9a, 9b are fixed. lOa and 10b are buffer pistons. On the other hand, the fixed contact parts 4a and 4b include arc contacts +1a and llb, and current-carrying contacts 12a and 12b.
, contact base 13a, and contact base L3b. Flexible contact part 3a, 3b and fixed contact part 4
a, 4b are supported and fixed by capacitor cylinders 14a, i4b, and further fixed to a joint case 15. The operating rods 5a and 5b are connected to a link mechanism part 16a in the joint case,
16b, and its link mechanism +6a, 16b
are connected and driven via an insulating rod 17. Arc extinguishing room 2a
The diameter of the side buffer cylinder 6a is smaller than the diameter of the buffer cylinder 6b on the arc extinguishing chamber 2b side. link mechanism part 16a,
16b has a link ratio larger on the arc extinguishing chamber 2a side than on the 2b side. Therefore, the stroke is longer on the arc extinguishing chamber 2a side than on the 2b side, and the opening speed is faster. Further, the capacitance of the capacitor tube on the arc extinguishing chamber 2a side is made smaller than the capacitance of the capacitor tube on the arc extinguishing chamber 2b side to increase the voltage sharing. However, in the circuit breaker of the present invention, the diameter of the buffer cylinder on the arc extinguishing chamber 2a side is small, so the speed of the blown gas does not increase, so there is no pressure drop along the nozzle, and the opening speed is fast and the stroke is long, so insulation recovery Characteristics also improve. As a result, it is possible to advance and improve the blocking characteristics.

〔Effect of the invention〕

As explained above, in the present invention, two arc extinguishing chambers with different buffer cylinder diameters are connected in series, and the voltage share on the arc extinguishing chamber side, which has good advanced small current interrupting characteristics, is increased to improve the advanced small current interrupting characteristics. We can provide a point breaker buffer type gas circuit breaker.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a buffer type gas circuit breaker showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional buffer type gas circuit breaker. 1... Containers 2a, 2b...
Arc extinguishing chamber parts 3a, 3b...movable contact part 4a
, 4b... Fixed contact portion 6a, 6b... Buffer cylinder 9a, 9b... Nozzle 14a,
14b...Capacitor cylinder agent Patent attorney Noriyuki Ken Yudo Ken Daishimaru

Claims (1)

[Claims] A container filled with an arc-extinguishing gas has a first arc-extinguishing chamber section and a second arc-extinguishing chamber section each consisting of a movable contact section and a fixed contact section that can be brought into and out of contact with each other, and the movable contact section The arc-extinguishing gas is compressed by a buffer piston and a buffer cylinder provided in the part, and the gas is guided to an insulating nozzle part to suppress the arc occurring between the arc contacts of the fixed contact part and the movable contact part. In a buffer type gas circuit breaker that cools and shuts off air by blowing air into the air, a first capacitor tube is connected in parallel to the first arc extinguishing chamber, and a second capacitor tube is connected in parallel to the second arc extinguishing chamber;
The buffer cylinder diameter of the first arc-extinguishing chamber is smaller than the second buffer cylinder diameter, and the opening speed and opening distance of the first arc-extinguishing chamber are equal to the opening speed and distance of the second arc-extinguishing chamber. 1. A buffer type gas circuit breaker, characterized in that the capacitance of the first capacitor tube is larger than the pole speed and the opening distance, and the capacitance of the first capacitor tube is smaller than the capacitance of the second capacitor tube.