JP2000299039A - Insulated operation rod for gas-blast circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a DC withstand voltage by setting a first portion near to the end face of a tubular insulated operating rod larger in outer diameter and smaller in inner diameter than a second portion apart from it, and covering outer/inner shields in contact with the outer periphery/inner periphery of the first portion apart from the second portion. SOLUTION: A first portion 1a at a fixed length from one end face, where an outer shield 2 and an inner shield 3 are connected together, of an insulated operation rod 1 made of RFP is formed larger in outer diameter by (2×d) and smaller in inner diameter by (2×d) than another second portion 1b. The outer shield 2 is firmly connected by a screw connection section 4 in contact with the outer periphery of the first portion 1a to cover the second portion 1b by the length L of one part apart by the distance (d). The inner shield 3 is firmly connected by the screw connection section 4 in contact with the inner periphery of the first portion 1a, and it is inserted into the hole of the second portion 1 b apart from the second portion 1b by the distance (d).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating operation rod for a gas circuit breaker used for a power gas circuit breaker for interrupting a current in a high power circuit.

[0002]

2. Description of the Related Art As shown in FIG. 12, a power gas circuit breaker is provided with a movable arc contact 102 and a fixed arc contact 103 in a closed container 120, and the movable arc contact 102 is operated by a driving unit 110. , For interrupting the current or controlling the electric system.
In general, a power gas circuit breaker is configured such that a driving unit 110 is grounded and an operation rod mechanically connecting a high voltage movable arc contact 102 and the driving unit 110 is an insulating operation made of glass fiber reinforced plastic or epoxy resin. A rod 101 is used. This insulating operation rod 101 is required to have good insulating properties at high voltage, and in order to satisfy the demand, a method of reducing the electric field concentrated at the end portion is as follows.
For example, JP-A-49-35896, JP-A-1-1544
19, various proposals have been made in JP-A-8-77853 and the like.

FIG. 10 is a cross-sectional view showing an end of an insulating operation rod of a conventional power gas circuit breaker described in Japanese Patent Application Laid-Open No. 8-77853. In FIG. 10, reference numeral 201 denotes an insulating operation rod made of a hollow cylindrical glass fiber reinforced plastic or the like having high mechanical strength. 202 is an outer shield, and 203 is an inner shield for reducing the electric field at the end of the insulating operation rod 201. The connection between the insulated operation rod 201 and the outer shield 202 and the inner shield 203 is connected by a screw connection portion 204 of the insulated operation rod because sufficient mechanical strength is required. FIG. 10 proposes coating the inner and outer circumferences of the insulating operation rod 201 with a liquid rubber casting material 205 having excellent weather resistance and electrical properties for preventing moisture absorption and electrification. Outer shield 202 and inner shield 2
The edge of 03 has a sufficient curvature to reduce the electric field so that the withstand voltage performance is not deteriorated. Since the electric field is high at the boundary between the insulating operation rod 201 and the outer shield 202, the inner shield 203, and the gas, a gap is provided between the insulating operation rod 201, the outer shield 202, and the inner shield 203 as illustrated. Have been.
In the conventional example of FIG. 10 as described above, the electric field at the end of the insulated operation rod 201 can be reduced with respect to the AC voltage which is the circuit voltage or the lightning impulse voltage when lightning enters the circuit.

[0004]

However, FIG.
Although the structure of the conventional example shown in FIG. 1 can effectively reduce the electric field at the end of the insulating operation rod 201 with respect to an AC voltage or a lightning impulse voltage, it is insulated with respect to a DC high voltage. There is a problem that the electric field at the end of the operation rod 201 cannot be sufficiently reduced. That is,
After opening the circuit breaker at the time of the small current interruption, the insulation operation rod 20
1, a high DC voltage that is as much as two to three times the circuit AC voltage may remain for a long time, but in such a case, a sufficient shielding effect cannot be exhibited and the withstand voltage performance is reduced. Was causing it.

More specifically, in the conventional insulated operating rod, the insulated operating rod 20 when an AC voltage is applied is used.
The distribution of equipotential lines at the end of the joint between the first shield 1 and the outer shield 202 (the part denoted by reference numeral 220 in FIG. 10 (hereinafter referred to as the end 220)) is as shown in FIG. Become. That is, FIG. 11A is an equipotential diagram for an AC voltage or a lightning impulse voltage at the end 220 of the conventional structure. FIG. 11 (b) shows an equipotential diagram for a DC voltage at the end 220 of the conventional structure. In FIGS. 11A and 11B, the same components as those in FIG. 10 are denoted by the same reference numerals.

As shown in FIGS. 11 (a) and 11 (b), the equipotential lines are formed by the outer shield 202 regardless of whether an AC voltage is applied or a DC voltage is applied.
11 and between the insulating operation rod 201, but when a DC voltage shown in FIG.
It can be seen that more equipotential lines enter the gap 230 and are dense. Due to this difference, the withstand voltage characteristics of the conventional insulated operating rod are lower when a DC voltage is applied than when an AC voltage is applied. That is, since the connection between the outer and inner shields and the insulated operation rod requires mechanical strength, screw connection is usually employed. There is a possibility that a minute gap (small gap) is formed between the two. Therefore, at the time of DC voltage application, as shown in FIG.
When many equipotential lines enter the space 230, the local electric field at the screw joint, especially at the screw joint end 231 becomes high, and the occurrence of partial discharge, which eventually triggers, may lead to flashover, This has been a cause of lowering the withstand voltage performance with respect to the high-voltage DC residual voltage.

In the equipotential diagrams of FIGS. 11A and 11B, the shape of the outer shield 202a is compared with that of the outer shield 202 of FIG. 10 as a simple shape in order to facilitate the simulation. However, the same can be said for the structure of FIG.

The present invention has been made in order to solve the above-mentioned problems of the conventional example. The shield shape of the insulating operation rod 1 of the power gas circuit breaker impairs the effect on the AC voltage or lightning impulse voltage. Instead, it is intended to provide a structure that works effectively even with a DC voltage, and to improve the withstand voltage performance of the insulated operation rod.

[0009]

In order to achieve the above object, a first insulating operating rod for a gas circuit breaker according to the present invention comprises a fixed arc contact and a movable arc contact in a sealed container filled with gas. A cylindrical insulating operation rod having an outer shield and an inner shield for moving the movable arc contact in the gas circuit breaker provided with: a first length of a predetermined length from one end face of the insulating operation rod; Is formed so that the outer diameter is larger and the inner diameter is smaller than the second portion, which is the other portion, and the outer shield has an inner peripheral surface having a diameter substantially equal to the outer periphery of the first portion. Having an inner peripheral surface that is in contact with an outer peripheral surface of the first portion and is separated from an outer periphery of the second portion so as to cover a part of the second portion. The first An outer peripheral surface having a diameter substantially equal to the inner peripheral surface of the second portion, the outer peripheral surface being in contact with the inner peripheral surface of the first portion, and being separated from the inner peripheral surface of the second portion to form a hole in the second portion It is provided to be inserted. The first insulated operating rod for a gas circuit breaker according to the present invention configured as described above is characterized in that the first portion of the insulated operating rod and the outer shield when the remaining high DC voltage is applied when a small current is interrupted. In addition, since the electric field concentration in the minute gap of the inner shield can be reduced, the occurrence of partial discharge which causes a decrease in withstand voltage can be suppressed.

Further, in the first insulating operating rod for a gas circuit breaker according to the present invention, the second portion of the insulating operating rod and the inner portion of the inner operating rod are used in order to more effectively reduce the concentration of the electric field in the minute gap. And an outer diameter and an inner diameter of the first portion of the insulated operation rod and a third portion of the first portion of the insulated operation rod so that a gap between the first portion and the outer shield electrode is 10% to 30% of a thickness of the first portion of the insulated operation rod. It is preferable to set the outer diameter and the inner diameter of the portion 2.

Furthermore, in the first insulating operation rod for a gas circuit breaker according to the present invention, the outer shield covers the second portion in the axial direction, and the inner shield has the second shield.
It is preferable to set the length in the axial direction to be inserted into the hole of the portion at 10 times or less the thickness of the first portion.

A second insulating operating rod for a gas circuit breaker according to the present invention moves the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. A cylindrical insulated operating rod having an outer shield and an inner shield, wherein the outer shield is in contact with an outer peripheral surface of a first portion having a predetermined length from one end face of the insulated operating rod, and The insulated operating rod is provided so as to cover a part of the second portion apart from the outer peripheral surface of the second portion except the first portion so as not to contact with the outer peripheral surface of the second portion. Is provided so as to be in contact with the inner peripheral surface of the first portion and to be inserted from the inner peripheral surface of the second portion to the middle of the hole of the second portion. In an inner peripheral surface which is not the outer peripheral surface and opposed to the inner shield which is not external shield facing,
An uneven portion in which concave portions and convex portions are alternately formed so as to reduce concentration of an electric field near a boundary between the first portion and the second portion is characterized. The insulating operation rod for a second gas circuit breaker according to the present invention configured as described above reduces the potential sharing on the surface of the insulating operation rod facing the outer shield and the inner shield,
When a high DC voltage remaining when a small current is interrupted is applied, electric field concentration in the minute gap between the first portion of the insulating operation rod and the outer shield and the inner shield can be reduced. Can be suppressed.

In the second insulating operation rod for a gas circuit breaker according to the present invention, it is preferable that the cross-sectional shape of the concave portion and the convex portion is semicircular.

Further, a third insulating operation rod for a gas circuit breaker according to the present invention moves the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. A cylindrical insulated operating rod having an outer shield and an inner shield, wherein the outer shield is in contact with an outer peripheral surface of a first portion having a predetermined length from one end face of the insulated operating rod, and The insulated operating rod is provided so as to cover a part of the second portion apart from the outer peripheral surface of the second portion except the first portion so as not to contact with the outer peripheral surface of the second portion. Is provided so as to be in contact with the inner peripheral surface of the first portion and to be inserted from the inner peripheral surface of the second portion to the middle of the hole of the second portion. In the second portion, a low-resistance layer is formed on a surface facing the outer shield and a surface facing the inner shield so as to have a lower surface resistance than other portions. And The third insulating operating rod for a gas circuit breaker according to the present invention having the above-described configuration includes the first portion of the insulating operating rod and the external shield when a residual high DC voltage is applied when a small current is interrupted. In addition, since the electric field concentration in the minute gap of the inner shield can be reduced, the occurrence of partial discharge which causes a decrease in withstand voltage can be suppressed.

Further, in the third insulating operation rod for a gas circuit breaker according to the present invention, the low-resistance layer may be formed of a SiC layer.

In the third insulating operation rod for a gas circuit breaker according to the present invention, the low-resistance layer can be formed by applying a resin containing silicon carbide (SiC) powder.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a partial cross-sectional view schematically showing a characteristic configuration of an insulated operating rod according to a first embodiment of the present invention.
And a connection portion with the internal shield 3. The insulating operation rod 1 is a tubular insulating member that is connected to the movable arc contact and moves the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. The operation rod has an excellent feature that the withstand voltage performance against a high-voltage DC residual voltage can be made similar to the case where an AC voltage is applied, by a configuration described in detail below.

More specifically, in the first embodiment, the insulating operation rod 1 is formed, for example, by winding a glass cloth made of a woven cloth of a glass fiber bundle to a predetermined thickness and then setting the thermosetting resin such as an epoxy resin. Hollow FRP (Fib
er Reinforced Plastics: a first portion 1a having a predetermined length from one end face to which the outer shield 2 and the inner shield 3 are connected has an outer diameter smaller than that of the second portion 1b which is the other portion. It is formed so that it becomes larger by (2 × d) and its inner diameter becomes smaller by (2 × d).

The outer shield 2 is formed in a cylindrical shape having an inner peripheral surface having a diameter substantially equal to the outer periphery of the first portion 1a of the insulating operation rod 1, and a part of the inner peripheral surface forms the first portion. 1a
Are fastened so as to maintain sufficient mechanical strength by using, for example, a screw connection (this portion is shown as a screw connection portion 4 in the drawing). In addition, the outer shield 2 is connected to the first portion of the second portion 1b.
Is provided so as to cover the portion of the length L from the boundary with the portion 1b. That is, the outer shield 2 is
The second portion 1b is separated from the outer periphery of the portion 1b by a distance d.
Is provided so as to cover a part thereof.

The inner shield 3 has a first portion 1a.
Has an outer peripheral surface having a diameter substantially equal to the inner periphery of
Insulated operating rod 1 so as to contact the inner peripheral surface of
In the center hole. Note that, similarly to the outer shield 2, the inner shield 3 is fastened to the inner peripheral surface of the first portion 1a by using, for example, a screw connection so as to maintain sufficient mechanical strength. Further, the inner shield 3 is provided so as to extend so as to be inserted from the boundary of the first portion 1b to the depth of the length L in the hole of the second portion 1b. Further, the inner shield 3 is inserted into the hole of the second portion 1b at a distance d or more from the inner periphery of the second portion 1b.

As described above, in the first embodiment, the thickness of the second portion 1b is made smaller than the thickness D of the first portion 1a of the insulating operation rod 1 having the screw connection portion 4. Thus, a distance d is provided between the outer peripheral surface of the second portion and the outer shield 2 and between the inner peripheral surface of the second portion and the inner shield 3. Here, the distance d is the screw coupling portion 4
In order to effectively reduce the electric field at the end of the insulating operation rod 1, the thickness is preferably 10% or more with respect to the thickness D of the first portion of the insulating operation rod 1. The longer the length L, which is the length of the outer shield 2 or the inner shield 3 protruding from the first portion 1a, the more the electric field at the end of the first portion 1a is reduced. Since the electric field in the gap between the third part 3 and the second part 1b becomes high, it is desirable that the distance d be 10 times or less.

Hereinafter, the electric field distribution in the insulated operating rod 1 according to the present invention shown in FIG. 1 will be described based on calculation results by simulation, in comparison with a conventional example.

FIG. 2 shows the result of calculating the electric field distribution when a DC voltage is applied to the conventional insulated operating rod 201 shown in FIG. 10 (only the area around the outer and inner shields is shown). A minute gap is likely to be formed at the lower end of the screw joint 204, and the electric field concentrates on the lower end of the screw joint 204 due to this gap. In order to evaluate such a state as a model, in this simulation, calculation was performed by providing a wedge-shaped minute gap 208 at the end of the screw connection portion 204 between the insulating operation rod 201 and the outer shield 202 and the inner shield 203.

FIG. 3 shows a result of calculating an electric field distribution when a DC voltage is applied to the insulated operation rod 1 of the first embodiment shown in FIG. 1 (only the area around the outer and inner shields is shown). In the vicinity of the boundary between the first portion 1a and the second portion 1b, that is, at the end of the screw connection portion 4, FIG.
Similarly to the above, the calculation was performed with the wedge-shaped minute gap 8 provided. still,
2 and 3, the electric field strength is shown corresponding to the length of the arrow. In both the present embodiment and the conventional example, the electric field intensity is maximized at the end of the wedge-shaped gap.
As is clear from comparison with the above, the length of the arrow indicating the intensity of the electric field concentrated in the gap near the boundary between the first portion 1a and the second portion 1b of the insulating rod 1 of the first embodiment is , Compared to the conventional example. That is,
In the first embodiment, the first portion 1 of the insulating operation rod 1
This indicates that the concentration of the electric field in the vicinity of the boundary between a and the second portion 1b can be reduced.

FIG. 4 shows the maximum electric field generated in the minute gap at the end of the screw joint between the insulating operation rod and the shield in the structure of the conventional example and the structure of the first embodiment when a DC voltage is applied. 7 is a graph showing a result of calculation using d / D as a variable, which is obtained by dividing the gap d of FIG. 5 by the thickness D of the insulating operation rod. From this calculation result, in the conventional structure, the maximum electric field hardly changes even if the gap d is increased. On the other hand, it can be seen that the maximum electric field in the structure of the first embodiment decreases as the gap d increases and the electric field concentrated on the minute gap generated at the end of the screw coupling portion 4 with the DC voltage can be reduced.

The gas circuit breaker is usually operated under high pressure (0.5M
(About Pa) SF ₆ gas is used. This is a medium having both the breaking performance and the insulating performance, and is designed by grasping the electric field value of each part so as not to exceed the design electric field value even in the insulating design of the insulating operation rod. FIG. 4 also shows design allowable electric field values. When a DC high voltage is applied, in the conventional structure, the insulating operation rod 201 and the screw connection portion 20
Since the maximum electric field of the minute gap 208 formed at the end of the fourth electrode exceeds the allowable electric field, a partial discharge occurs in this gap,
This can trigger insulation breakdown. On the other hand, when d / D exceeds 10%, the maximum electric field of the minute gap 8 in the structure of the first embodiment can be reduced to an allowable electric field value or less.
The occurrence of partial discharge in the gap 8 can be prevented, and the insulation reliability can be sufficiently ensured. In the structure of the first embodiment, d /
Although the maximum electric field in the gap 8 can be reduced as D is increased, it is reasonable to make d / D 30% or less in consideration of practical aspects such as mechanical strength of the insulating operation rod.

Next, the protrusion length L of the outer shield 2 and the inner shield 3 will be described. When a DC voltage is applied in the first embodiment, the equipotential lines between the outer shield 2 and the insulating operation rod 1 become extremely dense, as shown in FIG.
It is estimated from the conventional example shown in FIG. The concentration of the electric field between the outer shield 2 and the insulating operation rod 1 is related to the gap d and the projection length L. FIG. 5 shows the maximum electric field between the outer shield 2 or the inner shield 3 and the insulating operation rod 1 having the shape shown in FIG.
It is a graph which shows the result of having computed d as a variable. FIG.
Considering the design allowable electric field described together with the above, it can be understood that if the protrusion length L is set to be about 10 times or less of the gap d, it can be sufficiently within the allowable electric field value.

As described above, Embodiment 1 according to the present invention
Of the first portion 1a of the insulated operating rod 1 having the screw connection portion 4 with respect to the thickness D of the second portion 1
By reducing the thickness of b, a distance d is provided between the outer peripheral surface of the second portion and the outer shield 2 and between the inner peripheral surface of the second portion and the inner shield 3. . Thereby, the outer shield 202 and the inner shield 203
When a high DC voltage is applied, the electric field to the minute gap generated near the lower end of the screw connection part is different from the conventional example in which a step is provided and the space is provided below the screw connection part of the insulating operation rod. Concentration can be reduced, and the insulation resistance when a high DC voltage is applied can be improved.

Embodiment 2 Embodiment 2 according to the present invention
The insulating operation rod 11 will be described with reference to FIG. still,
6, the same components as those in FIG. 1 are denoted by the same reference numerals. Insulated operating rod 11 of the second embodiment
Is characterized in that irregularities 6 are formed on the surface of the inner peripheral surface and the outer peripheral surface other than the portion facing the outer shield and the portion facing the inner shield 3. With this configuration, when a DC voltage is applied, the screw coupling portion 4
The electric field concentrated on the end of can be reduced. That is, the electric field is related to the surface potential distribution of the insulating operating rod,
The surface potential allotment of the insulating operation rod 11 facing the outer shield 2 and the inner shield 3 is reduced and reduced.
Further, in the second embodiment, the unevenness 6 has a waveform formed by combining smooth semicircles as shown in FIG. 6, whereby the deformation of the surface electric field of the insulated operating rod 11 can be reduced, and the electric field can be more effectively reduced. Concentration can be eased.

Hereinafter, results of a simulation performed based on the configuration of the second embodiment will be described. First, FIG. 7A shows a calculation result of an electric field distribution near the outer shield 202 when a DC voltage is applied in the conventional example. Here, the magnitude of the electric field value is displayed corresponding to the length of the arrow. Note that the minute gap 81 at the end of the screw connection portion 4 is formed between the insulating operation rod 201 and the external shield 20.
The calculation is performed by providing a wedge-shaped gap having a quarter circular shape at the end portion in contact with 2. In FIG. 7A, the maximum electric field in the gap 8 obtained as a result is displayed as 100%. On the other hand, FIG. 7 (b) is an evaluation of the structure of the second embodiment shown in FIG. 6, and the surface of the insulating operation rod 1 is roughened except for a surface opposed to the outer shield 2 and the inner shield 3. 9 shows an electric field calculation result in the case where (combination) 6 is formed. Here, the gap 81 and the like are shown in FIG.
Calculation was performed in the same manner as in (a).

As shown in FIG. 7B, in the structure of the second embodiment, the maximum electric field in the gap 8 is reduced to about 74% as compared with the structure of the conventional example. This is because the potential was shared by the surface insulation resistance of the insulating operation rod 11 when a DC voltage was applied. That is, by forming the irregularities 6 on the surface of the insulating operation rod 11 other than the surface facing the outer shield 2 and the inner shield 3,
The electric field in the gap 8 is reduced because the surface potential shared by the insulating operation rod 11 facing the outer shield 2 is reduced. The unevenness 6 formed by combining the semicircles as shown in FIG. 7 (b) causes little deformation of the surface electric field distribution of the insulating operation rod 11, so that the electric field in the gap 8 can be effectively reduced.

The insulating operation rod 11 according to the second embodiment described above.
In this case, it is sufficient that a predetermined distance can be provided between the outer shield 2 and the insulated operation rod 11 and between the inner shield 3 and the insulated operation rod 11, which are located below the screw coupling portion 4. First of First Embodiment
It is not always necessary to provide a thick part and a thin part like the part and the second part. That is, as shown in FIG. 6, a thick part and a thin part may be provided in the insulating operation rod 11, and the insulating operation rod 11 is fixed in the axial direction as in the structure used in the simulation of FIG. And a step may be formed on the inner peripheral surface of the outer shield 202.

Embodiment 3 Embodiment 3 of the present invention will be described with reference to FIG. 8, the same components as those in FIGS. 1 and 6 are denoted by the same reference numerals. The insulating operation rod 21 according to the third embodiment has a non-linear resistance to an electric field (a high electric field) at a portion of the inner peripheral surface and the outer peripheral surface facing the outer shield and the portion facing the inner shield 3. A resin containing silicon carbide (SiC) powder exhibiting a property of lowering the resistivity when applied) to form a low-resistance layer.
Is characterized in that the electric field concentrated at the end of the light emitting element is reduced.

As described above, by lowering the surface insulation resistance of the portion of the insulating operation rod 21 facing the outer shield 2 and the inner shield 3, the portion of the insulating operation rod 21 facing the outer shield 2 and the inner shield 3 is reduced. The surface potential distribution can be reduced, and the electric field at the time of applying a DC voltage to the end of the screw coupling portion 4 can be reduced.

Hereinafter, results of a simulation performed based on the configuration of the third embodiment will be described. FIG.
FIG. 8A is similar to FIG. 8A described in the second embodiment.
In the calculation result of the electric field in the structure of the conventional example, the maximum electric field in the gap 8 is displayed as 100%. FIG. 9B shows the calculation results of the electric field when the low resistance layer 7 is provided on the surface of the insulating operation rod 21 facing the inner peripheral surface of the outer shield 2. Here, the resistivity of the low-resistance layer 7 is the same as that of the insulating layer rod 2.
Calculated as 1/10 of the insulation resistivity of 1. The maximum electric field of the gap 81 can be reduced to 50% or less of the maximum electric field of the conventional structure.

The low resistance layer 7 is made of silicon carbide (SiC).
By applying an epoxy resin, an acrylic resin, or a Teflon resin containing a thermosetting resin containing the powder, the effect of relaxing the electric field in the gap 8 can be improved. The electric field dependency of the resistivity of the acrylic resin filled with the SiC powder is such that non-linear resistance, which is insulative at a low electric field but lowers the resistivity at a high electric field, can be imparted to the low-resistance layer 7. Can be further reduced in the gap 8 in which As a result, the electric field can be effectively reduced, so that the occurrence of partial discharge under a high DC voltage can be effectively suppressed, and an insulated operation rod having a high withstand voltage can be obtained.

[0037]

As described above in detail, the first insulating operation rod for a gas circuit breaker according to the present invention has a second portion in which a first portion having a predetermined length from one end surface is another portion. The outer shield is formed so as to have a larger outer diameter and a smaller inner diameter, and the outer shield is in contact with the outer peripheral surface of the first portion at the inner peripheral surface and separated from the outer peripheral surface of the second portion at the second outer portion. The inner shield is provided so as to cover a part of the second portion, and the inner shield is in contact with the inner circumferential surface of the first portion at the outer circumferential surface and separated from the inner circumferential surface of the second portion. It is provided to be inserted into the hole. Thereby, in the first insulating operating rod for a gas circuit breaker according to the present invention, the first portion of the insulating operating rod and the outer shield and the inner shield when the remaining high DC voltage is applied when the small current is interrupted are applied. Since the concentration of the electric field in the minute gap can be reduced, it is possible to suppress the occurrence of partial discharge which causes a decrease in withstand voltage, and to improve the withstand voltage performance with respect to DC voltage.

In the first insulating operation rod for a gas circuit breaker according to the present invention, the gap between the second portion of the insulating operation rod and the inner and outer shield electrodes is respectively formed by the gap between the inner and outer shield electrodes. 10 of thickness of 1 part
% To 30% by setting the outer diameter and inner diameter of the first portion and the outer diameter and inner diameter of the second portion of the insulating operation rod, thereby more effectively concentrating the electric field in the minute gap. Can be effectively reduced, and the occurrence of partial discharge that causes a decrease in withstand voltage can be more effectively suppressed,
Withstand voltage performance against DC voltage can be further improved.

Further, in the first insulating operation rod for a gas circuit breaker according to the present invention, the outer shield covers the second portion in the axial direction, and the inner shield is the second shield.
By setting the length in the axial direction to be inserted into the hole of the portion to be 10 times or less the thickness of the first portion, the concentration of the electric field in the minute gap can be more effectively reduced. Thus, it is possible to more effectively suppress the occurrence of partial discharge that causes a decrease in withstand voltage, and to further improve the withstand voltage performance with respect to a DC voltage.

In the second insulating operation rod for a gas circuit breaker according to the present invention, the outer shield may be in contact with the outer peripheral surface of the first portion and not in contact with the outer peripheral surface of the second portion. The inner shield is provided so as to cover a part of the second portion at a distance, and the inner shield is in contact with an inner peripheral surface of the first portion and is separated from the inner peripheral surface of the second portion by the second shield. The first portion is provided on an outer peripheral surface of the insulating operating rod that is not opposed to the outer shield and an inner peripheral surface that is not opposed to the inner shield. Concavo-convex portions in which concave portions and convex portions are alternately formed are formed so as to reduce the concentration of the electric field near the boundary of the second portion. With the above-described configuration, the insulating operating rod for the second gas circuit breaker according to the present invention reduces the potential sharing on the surface of the insulating operating rod facing the outer shield and the inner shield, and reduces the potential of the insulating operating rod. The electric field concentration in the minute gap between the first portion and the outer shield and the inner shield can be reduced, and the occurrence of partial discharge can be suppressed, so that the withstand voltage performance against DC voltage can be improved.

Further, in the second insulating operating rod for a gas circuit breaker according to the present invention, when the cross-sectional shape of the concave portion and the convex portion is a semicircular surface having a smooth surface, the first portion of the insulating operating rod and the outer shield are formed. In addition, since the electric field concentration in the minute gap of the inner shield can be further reduced, and the occurrence of partial discharge can be suppressed, the withstand voltage performance against a DC voltage can be further improved.

Further, in the third insulating circuit rod for a gas circuit breaker according to the present invention, the outer shield is separated so as to be in contact with the outer peripheral surface of the first portion and not in contact with the outer peripheral surface of the second portion. The inner shield is provided in contact with the inner peripheral surface of the first portion and spaced apart from the inner peripheral surface of the second portion, and the outer shield is provided at the second portion of the insulating operating rod. A low resistance layer is formed on the surface facing the internal shield and the surface facing the internal shield so that the surface resistance is lower than that of the other portions. In the third insulating operation rod for a gas circuit breaker according to the present invention configured as described above, the minute gap between the first portion of the insulating operating rod and the outer and inner shields when a high DC voltage is applied. Can be alleviated, and the occurrence of partial discharge which causes a decrease in withstand voltage can be suppressed, so that the withstand voltage performance with respect to DC voltage can be improved.

Further, in the insulating operating rod for a gas circuit breaker according to the third aspect of the present invention, by forming the low-resistance layer with a SiC layer, it is possible to more effectively reduce the occurrence of partial discharge which causes a decrease in withstand voltage. Since it can be suppressed, the withstand voltage performance against a DC voltage can be further improved.

In the third insulating operation rod for a gas circuit breaker according to the present invention, the low resistance layer can be easily formed by applying a resin containing silicon carbide (SiC) powder.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view schematically illustrating an outer shield and an inner shield structure in an insulated operation rod according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a calculation result of an electric field when a DC voltage is applied in a structure of a conventional example performed for comparison with the insulating operation rod of the first embodiment.

FIG. 3 is a diagram showing a calculation result of an electric field when a DC voltage is applied to the insulating operation rod according to the first embodiment.

FIG. 4 is a graph showing a result of calculating a maximum electric field generated in a minute gap by using a ratio of a gap d between an insulating operation rod and a shield and a thickness D of the insulating operation rod as a variable in the first embodiment.

FIG. 5 is a graph showing a result of calculating a maximum electric field between the outer shield 2 or the inner shield 3 and the insulating operation rod 1 using L / d as a variable in the first embodiment.

FIG. 6 is a partial cross-sectional view schematically showing an outer shield and an inner shield structure in an insulated operation rod according to a second embodiment of the present invention.

FIG. 7A is a diagram showing an electric field calculation result when a DC voltage is applied in a structure of a conventional example performed for comparison with the insulating operation rod of the second embodiment, and FIG. 7B is a diagram showing the embodiment; It is a figure which shows the electric field calculation result at the time of direct-current voltage application in 2 insulating operation rods.

FIG. 8 is a partial cross-sectional view schematically illustrating an outer shield and an inner shield structure of an insulating operation rod according to a third embodiment of the present invention.

FIG. 9A is a diagram showing a calculation result of an electric field when a DC voltage is applied in a structure of a conventional example performed for comparison with the insulating operation rod of the third embodiment, and FIG. 9B is a diagram showing the embodiment; It is a figure which shows the electric field calculation result at the time of direct-current voltage application in the insulating operation rod of No. 3.

FIG. 10 is a diagram showing a structure of a conventional insulating operation rod.

FIG. 11 is a diagram showing a calculation result (a) of an electric field at an AC voltage and a calculation result (b) of an electric field at a DC voltage in the structure of a conventional insulating operation rod.

FIG. 12 is a diagram showing an outline of a general power gas circuit breaker for interrupting a current in a high power circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulated operation rod 2 External shield 3 Internal shield 4 Screw connection part 6 Uneven part 7 Low resistance layer
8,81 micro gap, 102 movable arc contact,
103 fixed arc contact, 110 drive, 12
0 Closed container.

Claims (8)

[Claims] 1. A cylindrical insulation having an outer shield and an inner shield for moving the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. An operating rod, wherein the insulating operating rod is formed such that a first portion having a predetermined length from one end face has a larger outer diameter and a smaller inner diameter than a second portion which is another portion. The outer shield has an inner peripheral surface having a diameter substantially equal to the outer periphery of the first portion, the inner peripheral surface being in contact with the outer peripheral surface of the first portion, and the outer shield being in contact with the outer periphery of the second portion. The inner shield is provided so as to cover a part of the second portion at a distance, and the inner shield has an outer peripheral surface having a diameter substantially equal to the inner periphery of the first portion, and the outer peripheral surface has the first portion. Contacting the inner peripheral surface of Min inner circumference apart from the second portion of the gas circuit breaker insulated operating rod, characterized in that is provided so as to be inserted into the hole. 2. A gap between the second portion of the insulating operating rod and the inner and outer shield electrodes is 10% to 3% of a thickness of the first portion of the insulating operating rod, respectively.
2. The insulating operating rod for a gas circuit breaker according to claim 1, wherein the outer diameter and the inner diameter of the first part and the outer diameter and the inner diameter of the second part of the insulating operating rod are set to be 0%. 3. The first shield has an axial length covering the second portion, and an inner shield has an axial length inserted into a hole of the second portion.
The insulating operation rod for a gas circuit breaker according to claim 1 or 2, wherein the thickness is set to 10 times or less the thickness of the portion. 4. A cylindrical insulation having an outer shield and an inner shield for moving the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. An operating rod, wherein the outer shield is in contact with an outer peripheral surface of a first portion having a predetermined length from one end surface of the insulated operating rod and a second portion excluding the first portion of the insulated operating rod The inner shield is provided so as to cover a part of the second portion so as not to be in contact with the outer peripheral surface of the second portion. The inner shield is in contact with the inner peripheral surface of the first portion of the insulated operating rod, and The outer peripheral surface of the insulating operating rod not facing the outer shield and the inner sheath are provided so as to be inserted from the inner peripheral surface of the second portion to the middle of the hole of the second portion. An inner peripheral surface that is not opposed to the field has an uneven portion in which concave portions and convex portions are alternately formed so as to reduce concentration of an electric field near a boundary between the first portion and the second portion. An insulating operating rod for a gas circuit breaker, characterized in that: 5. The insulated operating rod for a gas circuit breaker according to claim 4, wherein the cross-sectional shapes of the concave portion and the convex portion are each semicircular. 6. A cylindrical insulation having an outer shield and an inner shield for moving the movable arc contact in a gas circuit breaker having a fixed arc contact and a movable arc contact in a sealed container filled with gas. An operating rod, wherein the outer shield is in contact with an outer peripheral surface of a first portion having a predetermined length from one end surface of the insulated operating rod and a second portion excluding the first portion of the insulated operating rod The inner shield is provided so as to cover a part of the second portion so as not to be in contact with the outer peripheral surface of the second portion. The inner shield is in contact with the inner peripheral surface of the first portion of the insulated operating rod, and A second surface of the insulated operating rod, the surface facing the outer shield; An insulating operation rod for a gas circuit breaker, wherein a low resistance layer is formed on a surface facing the inner shield so as to have a lower surface resistance than other portions. 7. The insulating operating rod for a gas circuit breaker according to claim 6, wherein said low resistance layer is a SiC layer. 8. The low-resistance layer is made of silicon carbide (SiC).
7. The insulating operating rod for a gas circuit breaker according to claim 6, wherein the insulating operating rod is formed by applying a resin containing a powder.