JPH0435856B2 - - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to a high-voltage, large-capacity shield disconnector.

The short-circuit capacity of power systems continues to increase as demand for electricity increases and supply sources become more concentrated and unevenly distributed. Along with this, the responsibilities imposed on power switches and disconnectors are as follows:
These are an increase in the shearing capacity and a higher voltage. In recent years, the mainstream of high-voltage, large-capacity circuit breakers has been puffer-type gas circuit breakers that use _SF6 gas, which has excellent insulation and arc-extinguishing properties. Due to its excellent arc extinguishing properties, the arc breaking capacity per unit reaches 300kV50kA, and the combination of this unit
500kV63kA 2-point disconnection, 1100kV63kA 4-point disconnection is possible. However, the Patshua type gas disconnector,
The shearing characteristics are significantly affected by the rate of change of current near the current zero point (di/dt) and the rate of increase in the re-EMF voltage immediately after the current shearing (dv/dt), and the shearing current increases, causing di/dt. When dt becomes large, dv/dt increases, such as short-range line fault (SLF) short-range fault (SLF) fault, and short-range fault fault (ITRV), which includes high frequency component restart voltage (ITRV) caused by the line conditions on the bus side of the fault break. If the current is high, the current will drop within several microseconds after the
Thermal breakdown occurs at voltages from kV to several tens of kV or less, and a high percentage of shearing failures occur, indicating that the limits of the shearing characteristics are determined by this thermal breakdown. For this reason, when the rated current is large, it is often the case that a capacitor is inserted in parallel to the shear to make the dv/dt a little gentler and improve the shear characteristics caused by thermal breakdown. However, inserting a capacitor in parallel to the sheath disconnection has a major drawback in terms of insulation reliability, and it is necessary to use a condition without a parallel capacitor or a value as small as possible (for example, the voltage sharing ratio in multi-point disconnections or disconnectors). It is desirable to improve the capacity to the extent necessary for improvement.

On the other hand, vacuum insulation disconnectors have excellent insulation recovery characteristics, and there are only a few cases where the insulation fails due to thermal breakdown.The vacuum insulation disconnector has a characteristic of failing to disconnect due to dielectric breakdown after the voltage has recovered to a certain extent. . However, it is difficult to increase the withstand voltage per unit of vacuum shield disconnectors, and to date, the highest voltage known is 72kV.

When realizing high-voltage, large-capacity shields and disconnectors,
As mentioned above, the characteristics of gas insulation and disconnectors whose performance is determined by thermal breakdown, and the characteristics of vacuum insulation and disconnectors whose performance is determined by dielectric breakdown, are complementary to each other. It has been known for a long time to use a disconnector and a vacuum disconnector in series.

For example, JP-A-56-128527, JP-A-57-
36733 and Japanese Patent Application Laid-open No. 56-76128, a gas shield breaker and a vacuum shield breaker are connected in series, and a resistor and a capacitor are attached to each in parallel, so that the initial stage of the rise of the restart voltage is caused by a vacuum. There is a system in which the high voltage region after the initial thermal breakdown region has been cleared is applied to the gas tank or the disconnector.

In this way, devices in which a parallel impedance is inserted into the shingle section have disadvantages such as the overall shape becomes larger due to the size of the impedance element, and when stored in a container, the container becomes larger. There are also drawbacks such as problems with the reliability of the insulation of the parallel impedance elements.

In addition, by applying the excellent insulation characteristics of a vacuum insulation disconnector, insulation duties are borne by another insulation disconnector or a disconnecting switch. As disclosed in
Alternatively, a method is known in which the vacuum chamber or the disconnector is closed again after the disconnector is opened.

FIG. 1 schematically shows a shredder cutting device disclosed in Japanese Utility Model Publication No. 16687-1987. Vacuum switch 1
is composed of an aerial parallel switch 2 and a switch 3 arranged in series with them,
One end plate 4 of the vacuum switch 1 is connected to a terminal 6, and a contact 7 on the fixed side of the vacuum switch is connected to the end plate 4. The terminal 6 is connected to one sliding contact 8 of the parallel switch 2 . The other end plate 5 of the vacuum switch is electrically connected to a sliding contact 9, and the sliding contact 9 acts as one terminal for each of the parallel switch 2 and the series switch 3. . The movable contact 11 of the vacuum switch 1 is sealed by a bellows 12 and attached to the end plate 5 so as to be movable in the axial direction, and can be driven from the air by a rod 13.

The crank arm 14 is rotatable around a shaft 15 that is a fulcrum, and by rotating the crank arm 14 by a drive mechanism (not shown), the pin 16 is rotated.
Links 18 and 19 engaged with the crank arm 14 at 17 drive the vacuum switch and the parallel switches 2 and 3, respectively. At this time, since the position of the pin 16 is closer to the shaft 15 than the position of the pin 17, the stroke of the movable contact of the vacuum switch is shorter than the rotation angle of the crank arm 14. Further, protrusions 20 and 21 are formed on the leak 18, and after the leak 18 is displaced by a predetermined distance, the protrusion 20 is attached to the rod 13.
When the contactor 11 is engaged with the roller 22 attached to the roller 22, the contactor 11 is driven for the first time, and the vacuum switch is opened.
At this time, the movable contacts 23 of the switches 2 and 3 driven by the link 19 engaged with the crank arm 14 by the pin 17 are at the position 24, and the sliding contact 8
Since the movable contactor 23 is opened when the vacuum switch 1 is in a closed circuit state, it is opened without arcing. Next, while the movable contact 23 is in contact with the sliding contact 9, the contacts 7 and 11 of the vacuum switch 1 are opened, and the current is briefly cut off. ,
The switch 3 is opened without an electric arc, and the movable contact 23 is
When the position 5 is reached, the protrusion 21 of the link 18
However, by engaging the roller 26 in the fixed position and lifting the link 18, the protrusion 20 and the roller 22 attached to the rod 13 of the vacuum switch are disengaged, and the vacuum switch 1 is closed. According to this method, all the re-electromotive voltage immediately after the current is interrupted is withstandable by the vacuum switch, but the steady voltage and insulation specifications are withstandable between the poles of the switch 3. This embodiment has a drawback that it cannot be used as a high-voltage shedding device because it cannot be used when the switching surge that occurs immediately after the current is cut off is high and exceeds the withstand voltage of the vacuum switch.

An object of the present invention is to provide a high-voltage, large-capacity shield breaker having a structure in which the parallel impedance element inserted in the shield breaker can be eliminated or minimized.

The feature of the present invention is that when the puffer-type gas shield is opened to a certain extent and the current is able to withstand the peak value of the re-electromotive voltage after the current is cut off, the vacuum shield is opened and the current is cut off. The reason is that the vacuum shield and disconnector are closed after the completion of the process, so that high voltage is not applied to the vacuum shield and disconnector.

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, a vacuum shield breaker 32 and a puffer-type gas shield breaker 3 are installed in a tank 31 at ground potential.
3 is arranged, and the tank interior space 34 is filled with SF ₆ gas. The current flows from the terminal 35 through the conductor 37 in the pushing 36, through the contacts 38 and 39 in the vacuum shield breaker 32, and from the cylinder 40 of the puffer type shield breaker through the fixed contact 41 to other terminals. 35, and the vacuum shield disconnector and puffer type shield disconnector are electrically connected in series.

The operation of the shear cutting device shown in this embodiment is controlled by an operating device (not shown) that connects the gas-tight rod 42.
and pin 4 via the insulated operating rod 43.
Link 4 connected to insulated operating rod 43 at 4
5 and 46, each link connects the lever 47 and 48 to the respective fixed shaft 4.
9 and 50 to change the driving force direction, the link 51 for driving the vacuum shield and disconnector and the link 52 for driving the puffer and disconnector are driven.

The reason why a puffer-type gas chamber disconnector exhibits sufficient disconnection characteristics is to compress the puffer chamber to a certain extent, and after the fixed contact exits the nozzle, the conditions under which the current can be cut off are maintained for at least 0.5 cycles. It is necessary to persist. Therefore, the stroke of the puffer type cutter is required to be relatively long.
On the other hand, vacuum sheath breakers have a range of optimum distances between poles for current sheathing, and this length is small compared to the stroke of puffer type sheath breakers. Therefore, when driving a vacuum shield disconnector and a puffer-type gas shield disconnector with the same operating device, it is necessary to devise a way to change the stroke of each shield. , lever 4
By changing the lengths of arms 7 and 48, the stroke of the spine section is changed. In other words, the lever 47 makes the length of the arm connected to the link 51 smaller than the length of the arm connected to the link 45, thereby shortening the stroke of the vacuum chamber and disconnector side. , conversely, in the lever 48, the link 5
The arm connected to 2 is made longer to lengthen the stroke on the side of the blower and disconnector.

In order to take advantage of the excellent insulation recovery characteristics of a vacuum insulation circuit breaker, a puffer-type gas insulation circuit breaker must be installed in a vacuum state sufficient to withstand the peak value of the re-EMF voltage after a current interruption. It is necessary to adjust the contact opening time so that the insulation recovery characteristics of the contactor reach a state with excellent insulation recovery characteristics. In this embodiment, a link 18 having protrusions 20, 21 similar to those disclosed in FIG. 1 is connected to a link 51 for driving the vacuum shield and disconnector.
The roller 22 provided on the rod 13 that drives the movable contact 39 of the vacuum shield disconnector 32 and the protrusion 20 are configured to engage with each other with a clearance, and furthermore, when a predetermined displacement is achieved, the protrusion 21 By abutting against a roller 26 provided on the fixed part and pushing up the hinge 18, the engagement between the protrusion 20 and the roller 22 is released, and the movable side contactor is returned to the circuit closing position by the force of the spring 53. It is something.

The effect of re-closing a vacuum shield circuit breaker after the circuit breaking operation is that, first of all, when a large current is applied to a vacuum shield circuit breaker, welding occurs at the contact part, which deteriorates the circuit breaking characteristics. The second reason is that it is preferable to close the circuit in an arc-free state, and the second reason is that the closing speed of a gas cylinder or disconnector is generally faster than that of a vacuum circuit or disconnector.
This is because if the circuits are configured to close at the same time, the reliability of the vacuum breaker and disconnector will be reduced.

The opening time and re-closing time of the vacuum circuit breaker are as follows:
There is a close relationship between the shearing characteristics of the patchworker and the shearing characteristics of the disconnector. As mentioned above, it is preferable to set the state in such a way that the insulating characteristics of the vacuum type gas insulator or breaker can be obtained once the insulating characteristics of the puffer-type gas insulator or breaker have been sufficiently established. In general, the dielectric strength of a vacuum type gas disconnector improves after the fixed contact leaves the nozzle. Even if the initial part is cleared, when the peak value of the re-electromotive voltage is applied, the puffer type gas shield or disconnector will not be able to withstand the voltage, leading to dielectric breakdown of the entire disconnection device and failure to disconnect. It turns out. Therefore, it is preferable that the opening time of the vacuum shield and disconnector be selected to be approximately the same as the opening time of the puffer-type gas shield and disconnector. By doing so, it is possible for the insulation properties of the puffer-type gas cylinder and circuit breaker to reach the required performance in a time approximately equal to the time required for the vacuum cylinder and circuit breaker to obtain sufficient insulation recovery characteristics.

Regarding the re-closing time, at least after the vacuum breaker has established sufficient insulation recovery characteristics,
0.0.5 cycles should sustain its characteristics,
In this embodiment, the protrusion 21 comes into contact with the roller 26 and the protrusion 20 is removed from the roller 22 after 0.5 cycles after the contact of the vacuum shear disconnector is opened, and before the puffer-type sheath disconnector completes its stroke. It is necessary to do so.

According to this embodiment, it is possible to realize a grounded tank-type gas-insulated shearing device that has excellent thermal breakdown characteristics and can withstand high voltage.

FIG. 3 shows another preferred embodiment of the present invention, which is applied to an insulator type breaker. Vacuum shield disconnector 32, puffer type gas shield disconnector 33
It is housed in an insulator tube 61 filled with SF ₆ gas. In this embodiment as well, the lengths of the arms of the levers 47 and 48 are changed to shorten the stroke of the vacuum shield and disconnector compared to the stroke of the vacuum shield and disconnector, and furthermore, the stroke of the vacuum shield and disconnector is opened. delay the time,
The vacuum type gas shield disconnector ensures sufficient dielectric strength, and the vacuum shield disconnector has excellent insulation recovery characteristics in a state that can clear the peak value of the re-electromotive voltage after the current disconnection. . Therefore, in this embodiment, the lever 47 is provided with a hook function, the hinge 62 is coupled to the drive rod 13 of the movable contact 39 of the vacuum shield disconnector, the hinge 62 is provided with a protrusion 63, and the protrusion 63 and the lever hook are connected. The hook part 64 is driven in an engaged state, and when the hook part has been stroked by a predetermined displacement, the hook part is released and the vacuum shield and disconnector are closed by the force of the spring 53. The delay in the opening time of the vacuum shield and disconnector is
This is done by causing the fixed contact 38 to follow the movable contact by a predetermined distance using the spring 65.

According to this embodiment, it is possible to realize an insulator-type, gas-insulated sintering device that has excellent thermal breakdown characteristics and can withstand high voltage.

FIG. 4 shows another embodiment of the present invention, in which two puffer-type gas shields and disconnectors are configured in series, and
It has a structure in which one vacuum shield and disconnector are further arranged in series. In this embodiment as well, the contact opening time of the vacuum shield and disconnector is delayed compared to the puffer type gas shield and disconnector, so that the puffer type gas shield and disconnector can ensure sufficient insulation properties and When a state is reached where the peak value of the re-electromotive voltage can be cleared, a state with excellent insulation recovery characteristics of the vacuum shield and disconnector can be realized. Further, the stroke of the vacuum shield and disconnector is adjusted by the lever 71 so that it is shorter than the stroke of the puffer-type shield and disconnector. Further, it is possible to shift the vacuum shield breaker to a re-closing operation at the time of a predetermined displacement stroke by applying the mechanism shown in FIG. 2.

In this embodiment, it is necessary that the hinges 72 and 73 for driving the puffer-shaped sheath section engaged with the insulating operating rod 43 be made of an insulating material.

According to this embodiment, a high-voltage shear breaker having two puffer-type sheath breakers connected in series can realize a large-capacity sheath breaker with excellent thermal breakdown characteristics. In addition, the present invention can also be applied to multi-point cutting or cutting with three or more points of the puffer type cutting device.

According to the present invention, by utilizing the high insulation properties of a puffer-type shield breaker and the excellent insulation recovery characteristics of a vacuum shield breaker, a high voltage, large capacity shield breaker can be realized in a small size and with high reliability. .

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a conventional device, FIG. 2 is a partial sectional view of an embodiment of the present invention, FIG. 3 is a vertical sectional view of another embodiment of the present invention, and FIG. 4 is a further embodiment of the present invention. It is a principle structure diagram of an example. 31...Gas container, 32...Vacuum shield disconnector, 33...
Patshua type gas shield disconnector, 47, 48...lever,
18... Link, 20, 21... Protrusion, 22, 26...
Roller, 53...spring.

Claims (1)

[Scope of Claims] 1. In a container filled with an insulating/arc-extinguishing gas, a fiber-cut section using a puffer method, and a wire-cut section in vacuum that is electrically connected in series with the fiber-cut section. and a drive mechanism for driving the shear cutting section to open and close the path, wherein the operation process of the sheath cutting section in a vacuum is faster than the operation process of the sheath cutting section using the puffer method. Briefly, during the circuit opening operation, the contact opening time of the shingle break in the vacuum is delayed from the contact opening time of the shingle break in the puffer method,
The driving mechanism is configured so that the shearing section in vacuum shifts to a closed circuit operation before the shearing operation step is completed, and is in a closed circuit state after the shearing operation is completed. Shrinking device. 2. In the crinkle cutting device according to claim 1, the contact opening time of the crinkle breakage section in the vacuum is the time at which the fixed contact leaves the nozzle at the crinkle breakage section using the puffer method. A shear cutting device characterized in that the drive mechanisms are configured to substantially match each other. 3. In the shear breaker device according to claims 1 and 2, the time at which the shear breaker shifts to the closing operation in vacuum is 0.5 cycle of current frequency or later after the contact is opened. A shear cutting device characterized in that the drive mechanism is configured as follows.