JPH11265646A - Insulated switchgear - Google Patents

Abstract

(57) [Problem] To provide an insulated switchgear that is easy to use and has a simplified operation mechanism by automatically performing a series of operations of disconnection and disconnection. A movable electrode (2) has a closed position (Y1, an open position (Y2)).
Vacuum valve 1 that continuously moves at three disconnection positions Y3
In, the open position Y2 in the middle of the movement of the movable electrode 2 from the closed position Y1 to the disconnection position Y3 reduces the opening speed. As a result, the movable electrode 2 can be moved without lowering the breaking performance.
Can be moved to the disconnection position Y3, and a series of operations for shutoff and disconnection can be automatically performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an insulated switchgear having a function of interrupting a large current.

[0002]

2. Description of the Related Art Generally, a power receiving and transforming apparatus receives electric power by a circuit breaker, a disconnecting switch, and the like, converts the electric power into a voltage optimal for a load by a transformer, and supplies the electric power to the load. When performing maintenance and inspection of substation equipment, after disconnecting with a circuit breaker, open the disconnector to prevent reapplication from the power supply side, and operate the grounding switch to ground the residual charge and induced current on the power supply side. By flowing to the side, the safety of workers is ensured. The configuration of the power receiving and distribution equipment includes a circuit breaker 1, disconnectors 2, 3, and a grounding switch 4 in a unit room 13 filled with insulating gas, as in a gas insulated switchgear described in JP-A-3-273804. Are individually manufactured and stored. Further, as in the insulated switchgear described in JP-A-9-249076, the vacuum valve is provided with a function of stopping the movable conductor 9 at four positions of a closed position Y1, an open position Y2, a disconnection position Y3, and a ground position Y4. Some of them have integrated three functions of circuit breaker, disconnector and ground switch.

[0003]

In the case of an insulated switchgear in which circuit breakers and disconnectors are separately arranged, not only the size of the device is increased, but also, for example, a series of operations for disconnection and disconnection during maintenance and inspection cannot be performed continuously. This is not easy to use, and there is a possibility that the operator may make an erroneous operation.

[0004] Insulated switchgear in which a circuit breaker and disconnector are integrated in a single vacuum valve has a problem that the operating mechanism is complicated for the following reasons. Vacuum circuit breakers have an opening distance that is optimal for cutting off large currents.If the opening distance is too large, the area where metal particles emitted from between the electrodes diffuse will increase, and the surrounding insulation will be reduced. As a result, the insulation performance of the vacuum valve deteriorates. Further, since the arc length increases, the arc behavior becomes unstable, and the breaking performance may decrease. On the other hand, if the opening distance is too small, the transient recovery voltage applied between the electrodes after the disconnection will not be stopped, and dielectric breakdown,
That is, the interruption is impossible. Therefore, in the conventional insulated switchgear, the breaking operation has to be completed in a state where the movable conductor is temporarily stopped at the appropriate open position, and then the disconnection operation has to be performed individually, resulting in a complicated operation mechanism. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an easy-to-use switchgear in which a circuit breaker and a disconnector are housed in a single vacuum vessel and which can automatically perform a series of operations of disconnection and disconnection. It is to simplify and reduce the size of the mechanism.

[0006]

In order to achieve the above-mentioned object, the present invention provides an insulated switchgear according to the present invention, in which a fixed conductor, a movable electrode, and a movable electrode for driving the movable electrode are provided. Wherein the movable electrode moves at three positions: a closed position, an open position, and a disconnection position.
The movable conductor stops at two positions, a closed position and a disconnection position, and has a deceleration means for reducing the opening speed when the movable conductor reaches the open position on the way from the closed position to the disconnection position. is there.

Further, the present invention is an insulated switchgear which adjusts a breaking performance by changing an open position between a closed position and a disconnection position.

Further, the present invention comprises a fixed conductor which can be freely contacted / separated in a vacuum vessel, a movable electrode, and contact / separation means for driving the movable electrode, wherein the movable electrode is in a closed position, an open position, and a disconnection position. In the insulated switchgear that moves between the three positions, the movable electrode moves while accelerating from the disconnection position to the closed position.

Further, the present invention comprises a fixed conductor which can be freely contacted / separated in a vacuum vessel, a movable electrode, and contact / separation means for driving the movable electrode, wherein the movable electrode is in a closed position, an open position, and a disconnection position. Wherein the opening distance D2 at the opening position is 0.5 × D3 <D2 <0.7 × D3 with respect to the opening distance D3 at the disconnecting position. It is.

Further, the present invention comprises a movable electrode that opens and closes a fixed electrode and a grounding device correspondingly arranged in a vacuum vessel, and includes a closed position, an open position, and a movable position while the movable electrode moves from the fixed electrode to a grounding position. In an insulated switchgear that moves between three positions of a ground position, the movable electrode is disposed between a closed position and a ground position.
An insulated switchgear having deceleration means for stopping at one of two positions and reducing the opening speed when reaching the open position while moving from the closed position to the ground position.

Further, the present invention is an insulated switchgear which adjusts the breaking performance by changing between an open position, a closed position and a ground position.

The present invention further includes a movable electrode that opens and closes a fixed electrode and a grounding device correspondingly arranged in a vacuum vessel, and includes a closed position, an open position, and a movable position while the movable electrode moves from the fixed electrode to a grounding position. An insulated switchgear that moves from a grounded position to a closed position while accelerating the movable electrode, wherein the insulated switchgear moves in three positions of a grounding position.

Further, the present invention is an insulated switchgear provided with a shock absorber, which starts operating when the movable electrode reaches an open position, in a link portion of an operation mechanism.

According to the present invention, an opening / closing device for driving the movable electrode by a spring operating mechanism is provided, and an impact force absorbing spring is provided separately from the blocking spring of the spring operating mechanism, so that the movable electrode reaches the open position. An insulation switchgear that sometimes starts operating the impact force absorbing spring.

Further, the present invention is an insulated switchgear in which the spring constant of the impact force absorbing spring is larger than the spring constant of the cut-off spring.

Further, according to the present invention, the movable electrode is fixed to a vacuum vessel via a bellows, and a portion having a large spring constant is provided in a part of the bellows so that the spring constant of the entire bellows changes depending on the amount of expansion and contraction. And an insulated switchgear having a bellows formed so as to increase the overall spring constant when the movable electrode reaches the open position.

[0017]

FIG. 1 to FIG. 1 show an embodiment of the present invention.
2 will be described.

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 discloses a vacuum valve 1 having a shutoff function and a disconnection function.

First, the structure of the vacuum valve 1 will be described. Bushings 8 and 9 are provided around the grounded metal container 4 and connected to a bus or a load. The movable electrode 2 and the fixed electrode 3 which are arranged opposite to each other inside the metal container 4 are opened and closed to realize cutoff and closing. The fixed electrode 3 is connected to a bushing 9, and the movable electrode 2 is fixed to the bushing 8 via a flexible conductor 12. That is, in the vacuum valve 1, the bushing 9-fixed electrode 3-movable electrode 2-flexible conductor 1
A current flows through the path of 2-busing 8. An arc shield 14 is provided around the electrodes so as to prevent the arc A from directly touching the metal container 4 at the time of interruption, in order to avoid a ground fault. The arc shield 14 also has a role of preventing deterioration of insulation performance, such as scattering of metal particles emitted from the electrode at the time of interruption, and contaminating the insulating rod 7, for example. The movable electrode 2 is connected to the insulating rod 7 and is driven up and down by an operation mechanism provided separately from the vacuum valve 1 to open and close the fixed electrode 3 and the movable electrode 2. Further, the insulating rod 7 was fixed to the vacuum container 4 via the bellows 11, so that the insulating rod 7 could be driven while maintaining the vacuum.

The movable electrode 2 is in a closed position Y1 where the electrode contacts.
Stops at two disconnection positions Y3 where insulation is guaranteed even when a surge voltage such as lightning is applied. For example, JEC
As described in the standards 2300, 2310, etc., the withstand voltage between contacts of the disconnecting switch is set higher than that of the circuit breaker. Therefore, the opening distance when the movable electrode 2 exists at the disconnection position Y3, the insulation distance between the electrode and the arc shield 14, and the like must be designed in accordance with the withstand voltage specification of the disconnector. In addition, when the movable electrode 2 is at the disconnection position Y3, in order to ensure the safety of the worker, insulation coordination is performed so as not to cause insulation breakdown between the electrodes but to discharge to the ground side even in an emergency. It is necessary to plan. For example, as shown in FIG.
4 is smaller than electric fields E1 and E2 between
It is configured so that dielectric breakdown occurs in the discharge paths 42-43 instead of 1.

In order to make the opening and closing device as small as possible, the open position Y2 and the disconnection position Y3 may be determined in the following procedure. FIG. 4 shows the dependence of the withstand voltage between the electrodes and the blocking performance on the position of the movable electrode 2. The withstand voltage between the electrodes increases as the opening distance D increases. The breaking performance in the graph takes into account the withstand voltage characteristics in the vacuum valve after the breaking. If the opening distance D exceeds a certain value, the emission amount of the metal particles increases, and the metal particles adhere to the surface of the insulator, causing a problem that the withstand voltage decreases. Next, the open position Y
2. A method of determining the disconnection position Y3 will be described. The lower limit of the open position Y2 and the disconnection position Y3 are determined from the withstand voltage specifications of the circuit breaker and the disconnector. Next, the open position Y2 at which the blocking performance is maximized may be obtained in the hatched area in FIG. Although the insulation performance and the cutoff performance differ depending on the electrode shape, the opening distance D2 at the open position Y2 is generally 0.5 × D3 <D2 <with respect to the opening distance D3 at the disconnection position.
It may be adjusted so as to be 0.7 × D3.

The opening / closing characteristics of the movable electrode 2 will be described with reference to FIGS. FIG. 3 shows a time change of the position of the movable electrode 2 in the opening operation. The symbol P indicates the opening characteristics of the conventional insulated switchgear, and the symbol Q indicates the opening characteristics of the insulated switchgear of the present invention. The symbol Y2 is present between the closed position Y1 and the disconnection position Y3, and represents an open position that provides an optimal opening distance Di for blocking. If the opening distance D2 at the opening position Y2 is smaller than the optimal distance Di, the transient recovery voltage after the interruption cannot be cut off and interruption cannot be performed.
If the value is larger than i, the arc becomes unstable and the breaking performance is reduced, and the diffusion region of the metal particles is further widened and the insulating performance of the vacuum valve 1 is deteriorated. Therefore, in the conventional insulated switchgear, as shown by the opening characteristic P, after the movable electrode 2 is once stopped at the open position Y2 to complete the cutoff,
It was moved to the disconnection position Y3 by an individual operation. In this embodiment, the opening speed is forcibly reduced at the time t1 when the opening distance D becomes the optimum distance Di, as in the opening / closing characteristic Q, to maintain the opening distance D at the time of interruption at the optimum distance Di. It can be moved to the position Y3.

Specifically, an operation mechanism shown in FIG. 9 may be used. FIG. 9 shows an opening and closing device for operating the vacuum valve 1 shown in FIG. Reference numeral 30 denotes a blocking spring portion, which generates a driving force by opening the stored blocking spring 31 with a separately provided trip mechanism, and the driving force is transmitted to the insulating rod 7 through the shaft 22 or the like. Reference numeral 20 represents the stopper 20. The stopper 20 determines the moving distance of the movable electrode 2 by limiting the amount of rotation of the shaft 22, and adjusts the shaft 22 to collide with the stopper 20 when the movable electrode 2 reaches the disconnection position Y3. In addition, a shock absorber 21 is provided together with the stopper 20, and the operation is started when the movable electrode 2 reaches the open position Y2.

According to the operating mechanism described above, the opening speed is rapidly reduced when the movable electrode 2 reaches the opening position Y2, so that the opening distance D at the time of interruption is substantially maintained at the optimum opening distance Di. In this state, the disconnection is completed, and then the disconnection position Y3 is automatically set.
Move up to. In other words, a series of operations for shutting off and disconnecting can be automatically performed, so that a safe opening / closing device that is easy to use and that does not have the possibility of an erroneous operation by the operator. Further, the operation mechanism is simplified as compared with a conventional insulated switchgear that operates the shutoff and disconnection in two stages. Further, since the opening speed is reduced before the movable electrode 2 reaches the disconnection position Y3, the overstrokes O1 and O2 are almost eliminated, and the life of the bellows 7 is improved.

FIG. 5 shows a time change of the position of the movable electrode 2 in the closing operation. Symbol R indicates the closing characteristics of the conventional insulated switchgear, and symbol S indicates the closing characteristics of the insulated switchgear of the present invention. In the present invention, since the closing is started from the disconnection position Y3, the closing stroke is longer than that of the conventional insulated switchgear, and the closing speed immediately before the electrode contacts is increased. In a vacuum circuit breaker, there is a problem that an arc is ignited between the electrodes in a minute gap state immediately before closing, and the electrodes are welded after closing, and the operating mechanism requires a large tripping force greater than the welding force. However, in the present invention, since the charging speed is increased, the arc firing time, that is, the welding force of the electrodes can be reduced, and the operating mechanism can be downsized.

Further, since the breaking performance can be controlled by the opening position Y2, the opening position Y2 may be adjusted as long as the rated voltages are equal even for vacuum valves having different rated breaking currents. In other words, the same operation mechanism can be used,
It can be general-purpose, and can be made cheap.

Further, the present invention can be applied to a conventional vacuum valve shown in FIG. 6 or FIG. FIG. 6 shows a vacuum valve that drives the movable electrode 2 in the vertical direction. FIG. 7 shows a rotary operation type vacuum valve, in which an operation blade 10 rotates around a stopper 20 to open and close an electrode. The metal container 4 may be miniaturized as a floating potential, or may realize the above-described insulation coordination as a ground potential. In any case, the present invention can be implemented if the movable electrode 2 is stopped at the closed position Y1 and the disconnection position Y3, and the opening speed is reduced when the movable electrode 2 reaches the open position Y2.

It is needless to say that the present embodiment can be applied to a mechanism other than the spring operating mechanism, such as an air operating mechanism. Further, the same effect can be realized by constructing a control system such as servo and feedback by attaching a position sensor to the link portion instead of using a shock absorber.

(Embodiment 2) A second embodiment of the present invention is a vacuum valve in which a circuit breaker and a grounding switch are integrated, and the structure is shown in FIG. The fixed electrode 3, the movable electrode 2, and the grounding device 15, which are insulated from the metal container 4 by the insulating cylinders 16A, 16B, and 16C, are arranged around the metal container 4 having a floating potential or a ground potential, and the movable electrode 2 is closed. Position Y1 and ground contact position Y
Stop at 4. When the movable electrode 2 reaches the open position Y2 when moving from the closed position Y1 to the ground position Y4, the opening speed is reduced. As a result, it is possible to automatically and continuously operate the shutoff and the grounding with a single operation mechanism. In the vacuum valve 1 of FIG. 8, the movable electrode 2 is closed at the closed position Y1.
And the disconnection position Y3 to realize the functions of cutoff and disconnection, and to open and close the movable electrode 2 and the grounding device 15 with separate operation mechanisms to realize the grounding function. In this case, three functions of cutoff, disconnection, and grounding can be integrated in a single vacuum valve.
There is an advantage that the entire opening and closing device can be reduced in size.

(Embodiment 3) A third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, FIG.
Is provided with the function of the shock absorber 21 in the blocking spring portion of the spring operating mechanism 25 shown in FIG. FIG. 10 and FIG. 11 show the structure of the blocking spring portion 30. FIG. 10 is composed of a tension blocking spring 31 and spring support fittings 32 and 33 for fixing both ends thereof. The support bracket 32 stops at the position L1 when the movable electrode 2 is at the closed position Y1, at the position L3 when the disconnection position Y3 (or the ground contact position Y4), and passes through the position L2 when the movable electrode 2 reaches the open position Y2. . Here, an impact force absorbing spring 34 is separately provided outside or inside the blocking spring 31, and the impact force absorbing spring 34 starts operating when the support bracket 32 reaches the position L2.
FIG. 11 shows a case where a compression spring is used as the blocking spring 31. Also in this case, when the support bracket 32 reaches the position L2, the shock absorbing spring 34 starts operating. In the present embodiment, when the movable electrode 2 reaches the open position Y2, the impact absorbing spring 34 acts as a brake, so that the opening speed decreases. Therefore, the same effect as when the shock absorber 21 of the first embodiment is used is obtained. In addition,
If the spring constant of the impact force absorbing spring 34 is made larger than the spring constant of the cut-off spring 31, the overshoots O1 and O2 shown in the opening characteristic diagram of FIG. 3 become smaller and the oscillation period becomes longer. , The blocking performance is stabilized, and bellows 7
Life is also improved.

(Embodiment 4) FIG. 1 shows a fourth embodiment of the present invention.
2 will be described. This is a case where the bellows 7 has a function of reducing the opening speed. By providing the bellows 7 with a portion K1 having a large spring constant and a portion K2 having a small spring constant, while the movable electrode 2 moves at high speed, the portion K2 having a small spring constant mainly operates, and the movable electrode 2 is moved to the open position Y2.
Is reached, the portion K2 is in a sufficiently compressed state, and the portion K1 having a large spring constant starts to operate. That is, when the movable electrode 2 reaches the open position Y2, the opening speed is reduced. In this embodiment, there is an advantage that the operation mechanism used in the conventional circuit breaker can be used as it is.

[0032]

According to the present invention, in a vacuum valve in which a circuit breaker and a disconnector are integrated, a series of operations of disconnection and disconnection can be automatically performed, so that the usability is improved and the possibility of an operator's erroneous operation is reduced. lost. Further, the operation mechanism can be simplified and downsized compared to the conventional insulated switchgear operated in two stages.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a vacuum valve according to an embodiment of the present invention.

FIG. 2 is an enlarged view around an electrode in the embodiment of FIG. 1;

FIG. 3 is a graph illustrating the opening characteristics of an example of the present invention and a conventional vacuum circuit breaker.

FIG. 4 is a characteristic diagram for determining an open position Y2 and a disconnection position Y3 in the embodiment of the present invention.

FIG. 5 is a graph illustrating the closing characteristics of an example of the present invention and a conventional vacuum circuit breaker.

FIG. 6 is a side sectional view of a vacuum valve according to another embodiment of the present invention.

FIG. 7 is a side sectional view of a vacuum valve according to another embodiment of the present invention.

FIG. 8 is a side sectional view of a vacuum valve according to another embodiment of the present invention.

FIG. 9 is a conceptual diagram of an operation mechanism necessary for realizing the present invention.

FIG. 10 shows a cut-off spring portion of an operation mechanism necessary for realizing the present invention.

FIG. 11 shows a cut-off spring portion of an operation mechanism necessary for realizing the present invention.

FIG. 12 is a side sectional view of a vacuum valve according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum valve, 2 ... movable electrode, 3 ... fixed electrode, 4 ... metal container, 7 ... insulating rod, 8, 9 ... bushing, 10 ...
Operating blade, 11 ... Bellows, 12 ... Flexible conductor, 14 ... Arc shield, 20 ... Stopper, 21 ... Shock absorber, 25 ... Operating mechanism, 30 ... Breaking spring part, 31 ... Breaking spring, 34 ... Shock absorbing spring, Y1 , Y
2, Y3, Y4 ... position, L1, L2, L3 ... position, K
1, K2 ... part, O1, O2 ... overstroke, P,
Q: opening characteristics, R, S: closing characteristics, t: time.

Claims (11)

[Claims] 1. A vacuum vessel comprising: a fixed electrode, a movable electrode, and a movable electrode; and a contact / separation means for driving the movable electrode.
An insulated switchgear in which the movable electrode moves at three positions: a closed position, an open position, and a disconnection position, wherein the movable electrode stops at two positions, a closed position and a disconnection position, and the movable electrode is closed. An insulated switchgear comprising a decelerating means for reducing an opening speed when reaching an open position when moving from a position to a disconnection position. 2. An insulated switchgear according to claim 1, wherein said open position is changed between a closed position and a disconnection position to adjust the breaking performance. 3. A vacuum vessel comprising a fixed electrode which can be freely contacted / separated, a movable electrode, and contact / separation means for driving the movable electrode.
An insulated switchgear in which the movable electrode moves at three positions, a closed position, an open position, and a disconnection position, wherein the movable electrode moves from the disconnected position to the closed position while accelerating. 4. A movable electrode provided in a vacuum vessel, comprising: a movable electrode; and a movable electrode for driving the movable electrode, wherein the movable electrode is in a closed position, an open position, and a disconnection position. An insulated switchgear that moves between three positions, wherein the opening distance D2 at the open position is 0.5 × D3 <D2 <0.7 × D3 with respect to the opening distance D3 at the disconnection position. Insulated switchgear. 5. A movable electrode which opens and closes between a fixed electrode and a ground electrode correspondingly arranged in a vacuum vessel, and includes a closed position, an open position and a ground position while the movable electrode moves from the fixed electrode to the ground electrode. In the insulated switchgear that moves the position, the movable electrode stops at two positions, a closed position and a ground position, and when the movable electrode reaches the open position when moving from the closed position to the ground position, the opening speed is reduced. An insulated switchgear having a deceleration means for decelerating. 6. An insulated switchgear according to claim 5, wherein said open position is changed between a closed position and a ground position to adjust the breaking performance. 7. A movable electrode which opens and closes between a fixed electrode and a grounding device correspondingly arranged in a vacuum vessel, wherein a closed position, an open position and a grounding position are provided while the movable electrode moves from the fixed electrode to the grounding device. An insulated switchgear, wherein the movable electrode stops at two positions, a closed position and a ground position, and the movable electrode moves from the ground position to the closed position while accelerating. 8. An insulated switchgear, wherein a shock absorber that starts operating when the movable electrode according to any one of claims 1 to 5 reaches an open position is provided at a link portion of an operation mechanism. 9. An opening and closing device for driving the movable electrode according to claim 1 by a spring operating mechanism,
An insulated switchgear, wherein a shock absorbing spring is provided separately from the cut-off spring of the spring operating mechanism, and when the movable electrode reaches an open position, the operation of the shock absorbing spring is started. 10. An insulated switchgear, wherein the spring constant of the spring for absorbing impact force according to claim 9 is larger than the spring constant of the cut-off spring. 11. The bellows according to claim 1, wherein said movable electrode is fixed to a vacuum vessel via a bellows, and a portion of said bellows having a large spring constant is provided. And a bellows formed so that when the movable electrode reaches the open position, the whole spring constant is increased.