JPS6161321A - 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] The present invention relates to a high-pressure gas blowing circuit breaker used in a power system substation or switchyard, particularly an I-5 sofa type SF.
6 Gas breaker C: A buffer type gas breaker with an improved arc extinguishing chamber to improve the interrupting performance of the breaker:
: It is related to.

[Technical background of the invention and its problems] Increasing demand for electricity (the capacity of power generation and substations continues to increase.Moreover, it is difficult to construct power plants in urban areas where BTM costs are high). Therefore, the transmission lines 11 are becoming longer distances, and in order to improve power transmission efficiency, there is a trend toward higher voltage.Currently, the highest power transmission voltage in Japan is 550K.
There are already plans for %100 OKV class power transmission.

As the capacity of power transmission systems increases, the breaking capacity required of circuit breakers used in substations and switchyards continues to increase, and currently, in 550 KV systems, the breaking current is 63.
Even KA's has been put into practical use.

This 550KV'-63KA is configured with 4 points of cutting, and if this is applied as is to a 100OKV system, it will correspond to 8 points of cutting. In order to improve the reliability of a breaker, it is important to reduce the number of breaker points and the number of parts as much as possible. The ninth point (second number) is g, which requires increasing the breaking capacity per breaking point.

For transmission voltages above 168KV, a buffer type SF'6 gas breaker is generally used. This is due to the excellent breaking performance and insulating performance of SF6 gas, but the 7-A type has a simpler structure compared to the 2-voltage 2, so it has become the mainstream of high-pressure circuit breakers. In addition, the entire substation equipment is SF
Figure 5 shows the arc extinguishing chamber of a buffer type gas breaker in a closed type gas switchyard insulated with 6 gases. An arc-extinguishing gas of 5F (class 1) is sealed in a container (not shown), and the arc-extinguishing chamber shown in FIG. A buffer cylinder 2 that slides on the outer periphery of the piston and an operating rod 6 that slides on the inner circumferential surface tl of the buffer piston 3 are attached around this.One end of the operating rod 6 is connected to an operating mechanism (not shown), and the other The movable electrode 1 and the buffer cylinder 2 mentioned above are fixed to the end.The operating cylinder is opened and closed by an operation mechanism (not shown).As a result, the movable electrode 1 is opened and closed between it and the corresponding fixed electrode 5. The buffer cylinder 2 generates compressed gas through relative movement with the buffer piston 3, and this compressed gas is passed through an insulating nozzle 4 arranged around the electrode 1 and fixed to the buffer cylinder 2. This insulated nozzle 4 has a scraping small part 4g (throat) on the side of the movable electrode 1 opposite to the fixed electrode 5.When the current is cut off, the fixed and movable electrodes 4. 5, a high-speed gas flow is applied to the t-arc 16 to break it.

However, the gas pressure in the space between the buffer cylinder 2 and the buffer piston 3, that is, in the buffer chamber 13, is inversely proportional to the distance between the inner wall of the back cylinder 2 and the tip of the buffer piston 3. Therefore, even within the range where the arc cannot be extinguished from the start of the opening operation until the fixed electrode 5 passes the scraped small part 4a of the insulated nozzle 4, the space between the buffer cylinder 2 and the buffer piston 3', that is, the buffer chamber 13 is As the gas continues to be compressed, the gas pressure within the buffer chamber 13 becomes extremely high. The gas compressed to high pressure in the buffer chamber 13 flows out through the hollow part of the operating rod 6, the gap between the fixed electrode 5 and the scraping small part 4a of the insulated nozzle, etc., without contributing to the IAH. In addition, since the gas is compressed to a higher pressure than necessary in the space between the buffer cylinder 2 and the buffer piston 3, that is, within the buffer chamber 13, a reaction force is generated in the buffer cylinder 2, and the speed increases to a predetermined opening speed. It took a long time to do that. Therefore, the voltage value is very high (42
0ff or higher) In a single-point circuit breaker, the increase in recovery voltage after the electrodes open may exceed the dynamic insulation recovery voltage between the electrodes, as shown in Figure 6, and the circuit breaker may re-ignite in the middle of opening. There is a fear that it will happen next time. FIG. 6 will be explained in more detail.

In the figure, two types of curves a and b are two types of stroke curves of the movable electrode, and it can be seen that the speed of the movable electrode according to curve a is faster than that of the movable electrode according to curve a.

Curves c and d are respectively curve a.

It represents the insulation recovery characteristics between the fixed and movable electrodes according to curve lab. Furthermore, curve e is a voltage waveform between the fixed and movable electrodes (two voltage waveforms), and the fact that curve e and curve lsd intersect means that the cutoff by stroke curve b is a failure; conversely, curve #!e and curve C The fact that they do not intersect means that the cutoff by stroke curve a is successful.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and is designed to avoid unnecessary compression in the space between the buffer cylinder and the buffer piston, that is, in the buffer chamber, until the fixed electrode passes through the scraped small part of the insulated nozzle. In order to reduce the reaction force of the compressed gas in the buffer chamber after the start of the polar opening movement l''F-, the initial speed is quickly increased to a predetermined speed, and a high voltage (for example, 4204 or higher) is applied to fP. The object of the present invention is to improve the insulation recovery characteristics of a single-point circuit breaker against advanced small current interruption, and to provide a buffer type gas breaker with excellent interruption performance.

[Summary of the Invention] In order to achieve the above object, according to the present invention, a slidable buffer piston is provided between the buffer cylinder and the movable support, and the buffer piston and the buffer cylinder form a buffer chamber. Moreover, the gas in the buffer chamber is compressed near the stroke end using spring force.

[Embodiment of the Invention] Next, an embodiment of the present invention will be described with reference to FIG. Figure 1, like Figure 5, shows the vicinity of the arc extinguishing chamber. Pole 1 connects the operating rod 6 to the buffer cylinder 2.
The other end of the o hanging rod 6 fixed together with the o buffer cylinder 2 is connected to an operating mechanism (not shown).
A buffer piston 3 is slidably disposed inside the buffer piston 3 , and the buffer piston 3 is further slidably disposed on a fixed support section 7 supported by a fixed section 17 .

The spring stopper portion 7a at the tip of the fixed support portion 7 and 1. A compression spring 1L is provided between the piston portion 3a of the buffer piston 3 and the rear end portion 3b of the buffer piston 3, respectively.
Place 12. The spring constant of the spring 11 is set to be larger than that of the spring 12.

Further, the initial compression load of the spring 11 is set to be greater than the frictional force of the sliding portion between the buffer cylinder 2 and the buffer piston 3, and the maximum load of the spring 12 is set to be weaker than the frictional force. An insulating nozzle 4 having a strobe portion 4a at its tip so as to surround a movable electrode is fixed to the buffer cylinder 2 by a metal nozzle 8. The nozzle presser 8 comes into contact with the fixed side current-carrying contact 9 when the nozzle is turned on. The fixed-side current-carrying contact 9 is surrounded by a fixed shield 10 that relieves the electric field of the fixed electrode 5 and the fixed-side current-carrying contact 9 .

Next 1: The operation of the present invention will be explained. In the closed state shown in FIG. 1, the frictional force at the sliding portion 14 between the buffer cylinder 2 and the buffer piston 3 is stronger than the force of the spring 12, as described above. It stands still in a certain position.

A cutoff signal is input to the operating mechanism (not shown), and a driving force is applied in the opening direction, causing the operating rod 6 to move toward the fixed part 17, causing the buffer cylinder 2 and buffer piston 3 to move.
Since there is M vibration force in the sliding part 14 between the operating rod 6
The buffer piston 3 also moves together with the buffer cylinder 2 which is fixed to the buffer cylinder 2 . As the operating rod 3 moves from the start of operation, the spring 11 becomes more energized. When the operating rod 3 comes to a position where the stored force of the spring 11 becomes larger than the frictional force of the sliding part 14 between the buffer cylinder 2 and the buffer piston 3, the buffer cylinder 2 and the buffer piston 3 The resulting space, that is, the buffer chamber 13, begins to be compressed (Fig. 2).Then, near the end of the stroke, the pressure within the buffer chamber 13 reaches its maximum value, and the pressure decreases, but the pressure and the sliding part 14
When the sum of the frictional forces becomes smaller than the spring force of the spring 11, the buffer chamber 13 is compressed again. The state at the end of the stroke is shown in Figure 3.

The above relationship will be explained with reference to FIG. 4. Curve f is the stroke curve of the movable electrode.

The pressure curve in the buffer chamber of the conventional arc extinguishing chamber shown in FIG. As shown, the arc extinguishing chamber according to the present invention can last for a longer time (
It is possible to blow gas onto the arc (until near the end of the stroke).

In the above embodiment 9J, at the initial stage of electrode opening, the buffer cylinder 2 and the buffer piston 3 are interlocked by the frictional force of the sliding part 14, and the buffer chamber 13 acts so as not to be compressed. is not necessarily limited to this, and by selecting the spring constant of the spring 11, it is also possible to configure such that the buffer chamber 13 is partially compressed even in the initial stage of opening.

[Effects of the Invention] As described above, according to the present invention, a slidable piston is provided between the buffer cylinder attached to the movable electrode and the support fixed to the fixed insulator on the movable side, and By providing spring stoppers at the selling end of the support and the upper and lower ends of the piston, and by providing springs between the spring stopper of the support and the upper end of the piston, and between the spring stopper of the support and the lower end of the piston, the instant the driving force is applied, Since the buffer piston operates together with the operating rod and the buffer cylinder, no force is required to compress the space between the buffer cylinder and the buffer piston.

Therefore, when the operating rod is pulled using the conventional g power, there is no compressive force, so the required speed can be quickly reached. Further, the compressive force does not work until the fixed electrode and the movable electrode are opened and the fixed electrode passes through the nozzle throat, and then the spraying due to compression occurs. Furthermore, after the operating rod moves to the end of its stroke, the spring force causes the buffer piston to compress the space between the buffer cylinder and the buffer piston, so the long-term spraying has an effect on the arc. Therefore, for advanced small current interruption performance, the opening speed can be increased (-, thus improving the performance), and for short circuit current interruption.
It is possible to provide a buffer type gas breaker that can effectively utilize gas and has good performance and high reliability.

[Brief explanation of the drawing]

Figures g1 to 3 are cross-sectional views showing the arc extinguishing chamber of a buffer type gas breaker showing one embodiment of the present invention, in which Figure 1 is in the closed state, Figure 2 is in the open state, and Figure 3 is in the open state. A sectional view showing the next state after the buffer piston operates, Figure 4 is a diagram showing the buffer type gas cutoff of the present invention: A diagram showing the stroke and pressure curve when the vessel is operated to shut off, Figure 5 is a diagram showing the conventional buffer type gas cutoff. FIG. 6 is a cross-sectional view showing the arc extinguishing chamber of the gas breaker, and is a diagram showing the recovery voltage applied between the electrodes and the insulation recovery characteristics between the electrodes when a small current is interrupted. 1...Movable electrode 2...Buffer cylinder 3
... Buffer piston 4 ... Insulation nozzle 5 ...
・Fixed electrode 6... Operating rod 7... Fixed support part 8 River shield 9... Fixed side energizing contact l
O...Fixed seal, Do11, 12...Spring
13... Space (buffer chamber) 14... Sliding part
16...Arc 17...Fixed part

Claims (1)

[Claims] 1. A fixed electrode and a movable electrode are disposed facing each other so as to be able to come and go in a container sealed with arc-extinguishing gas, and a buffer cylinder attached to the movable electrode and the inner periphery of this buffer cylinder are provided. A buffer chamber is formed with a buffer piston that is slidably disposed in the movable electrode, and when the movable electrode and the fixed electrode are separated, the gas in the buffer chamber that is compressed as the movable electrode moves is blown onto the arc generated between the two electrodes. In the buffer-type gas tank disconnector, the buffer piston is slidably arranged on a fixed support that directly or indirectly holds the movable electrode, and the buffer piston is inserted into the movable electrode between the fixed support and the buffer piston. A buffer-type gas tank and disconnector characterized in that it is provided with a first spring that moves the gas in the direction. 2. The buffer type gas cylinder disconnector according to claim 1, wherein a second spring is provided between the fixed support portion and the buffer piston to move the buffer piston in the direction in which the movable electrode is removed. 3. The buffer type gas shield disconnector according to claim 2, wherein the spring constant of the first spring is larger than that of the second spring.