JP3408269B2 - Disconnector with resistance - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnector with a resistor used in a substation, and more particularly to a resistor having excellent electrical and mechanical reliability. The present invention relates to the structure of a disconnector with a resistor used. 2. Description of the Related Art Generally, a gas insulated switchgear includes a circuit breaker, a disconnector, a grounding switch, and a current transformer in an airtight container filled with an insulating medium such as SF ₆ gas at about 3 to 6 atm. It is configured to house equipment necessary for opening and closing operations such as instruments and instrument transformers. Among these, the opening and closing operation of the disconnector is usually performed with the circuit breaker opened. With the switching operation of the disconnector, a surge called a disconnector surge occurs between the poles of the disconnector and propagates in the gas-insulated switchgear. In the UHV class, the disconnector surge becomes so large as to threaten the insulation of the gas-insulated switchgear, and therefore, it is necessary to take some measures. Conventionally, for the purpose of suppressing the voltage level at which such a disconnector surge occurs, a disconnector with a resistor of a type schematically shown in FIG. 2 has been proposed.
As shown in this figure, a tank 1 filled with an insulating medium such as SF ₆ gas contains a movable contact portion 2 and a fixed contact portion 3.
Are arranged on a coaxial line, and a movable contact 4 is arranged between the contact portions 2 and 3. When the movable contact 4 slides linearly in the axial direction of the contact portions 2 and 3, The disconnector is configured to be opened and closed. That is, fingers 5 and 6 that come into contact with the movable contact 4 are provided on the inner peripheral portions of the movable contact 2 and the fixed contact 3, respectively. Of the fixed side contact portion 3 while being in constant contact with the finger 5 of the fixed side. [0004] Around the fixed contact portion 3, a resistor shield 7 for electrolytic relaxation is arranged, and between the movable contact 4 and the resistance contact 8 of the resistor shield 7 when the disconnector is turned on. Is configured to have a gap g. This gap g is caused when the re-ignition occurs between the disconnector poles at the time when the tip of the movable contact 4 is located near the resistance contact 8 during the opening / closing operation of the disconnector. Is energized by flashover, and at this time, it is determined by considering the insulation emphasis surface so that the dielectric breakdown does not occur between the movable contact 4 and the fixed contact portion 3 or the tank 1. Further, the resistor shield 7 is connected to the fixed contact portion 3 via a resistor 9 having a value capable of sufficiently suppressing disconnector surge. Re-ignition occurs between the movable contact 4 and the resistance contact 8 a plurality of times during the switching operation of the disconnector, but the disconnector surge level at this time is sufficiently suppressed by the resistor 9. The material and structural aspects of the resistor 9 are currently being studied. FIGS. 5 to 7 show an example of the configuration of a conventional disconnector with a resistor adopting the above-described method. In this case, FIG. 5 is a configuration diagram showing the entire disconnector, FIG. 6 is a configuration diagram showing the ceramic resistor of FIG. 5, and FIG. 7 is a view taken in the direction of the arrow X in FIG. First, as shown in FIG. 5, in a tank 1 filled with SF ₆ gas, a movable contact portion 2 and a fixed contact portion 3 are arranged on a coaxial line in a vertical direction, and a movable contact 4 is provided therebetween. The disconnector is opened and closed by sliding linearly. The movable contact 4 is driven via an opening / closing mechanism 11 by an operating device 10 mounted on the upper part of the tank 1. That is,
The rotational driving force of the operation device 10 is configured to be converted from a rotational motion into a linear motion by the opening / closing mechanism 11 and transmitted to the movable contact 4. The resistor shield 7 is disposed between the movable contact portion 2 and the fixed contact portion 3, and a resistance contact 8 is provided at an inner peripheral end thereof. The resistance contact 8 is configured to face the movable contact 4 via the gap g in the closed state. As shown in FIGS. 5 and 7, a plurality of (four in the figure, for example, four) ceramic resistors 21 extending downward are provided below the outer peripheral end of the resistor shield 7 around the fixed contact portion 3. Are arranged at equal intervals and are attached to the resistor shield 7, and the lower ends of these ceramic resistors 21 are attached to the fixed side contact portion 3 by the connection portion 12. More specifically, as shown in FIG. 6, the ceramic resistor 21 is formed by laminating a plurality of ring-shaped resistors 21a and penetrating an insulating bolt 21b through a hollow portion thereof. Then, one end of the insulating bolt 21b is attached to the resistor shield 7 and the other end is attached to the connection portion 12, whereby the ceramic resistor 21
And, the resistor shield 7 is supported by the connection portion 12 (and thus by the fixed contact portion 3). In this case, as shown in FIG. 7, the mechanical strength of the insulating bolt 21 b is relatively weak, so that the strength is compensated for and the ceramic resistor 21 and the resistor shield 7 are securely supported on the connection portion 12. , Between adjacent ceramic resistors 21
Similarly, a total of four insulating rods 22 extending downward are arranged one by one. [0008] As shown in FIG.
And the fixed side contact portion 3 with respect to the upper and lower ends of the tank 1
Each is supported by the insulating cylinder 13. From the side surfaces of the movable contact portion 2 and the fixed contact portion 3, connection conductors 14, 15 are respectively led out in the horizontal direction, and are drawn out to the outside by an insulating spacer 16. In this case, the connection conductor 15 derived from the fixed side contact portion 3 is
2 below. As shown in FIG. 5, when the ceramic resistor 21 is used as the resistor, as described above, the mechanical strength is compensated for and the ceramic resistor 21 is used. 21 and the resistor shield 7 to the connection portion 1
For the purpose of securely supporting 2, as shown in FIG.
It is necessary to arrange a plurality (four as an example in the figure) of insulating rods 22 in parallel with the ceramic resistor 21.
As a result, in the space B between the resistor shield 7 and the connection portion 12, as shown in FIG. 7, a large number of ceramic resistors 21 and insulating rods 22 are arranged at a narrow interval A. However, there is a disadvantage that it becomes complicated. In the fixed contact portion 3, in addition to disposing the connecting conductor 15, the resistor shield 7, the ceramic resistor 21, and the connecting portion 12 for connecting the ceramic resistor to the fixed contact 3 are provided. In particular, as is clear from FIG. 5, since the length of the ceramic resistor 21 is long, the axial dimension of the entire fixed-side contact portion 3 is long. As a result, there is a disadvantage that the size of the entire disconnector becomes large. The present invention has been proposed to solve the above-mentioned problems of the prior art, and an object of the present invention is to use a resistor having high mechanical strength and simplify the structure near the resistor. And reduce the axial dimension of the fixed contact part,
An object of the present invention is to provide a disconnector with an excellent resistance which can contribute to the miniaturization and simplification of the entire disconnector. According to the present invention, there is provided a disconnector with resistance according to the present invention, wherein a movable side contact portion and a fixed side contact portion are arranged on a coaxial line in a sealed container in which an insulating medium is sealed. A movable contact is arranged between the side contact portion and the fixed side contact portion, and a resistor shield is arranged around the fixed side contact portion. The resistor shield is connected to the fixed side contact portion via a resistor. Connected with the movable contact, and further has a structure in which connection conductors are respectively derived from the movable contact and the fixed contact, with a resistor that opens and closes an electric circuit by operating the movable contact. In the disconnector, the resistor is formed by casting the entire resistance wire with an epoxy resin. In this case, the connection conductor derived from the fixed contact portion may be arranged in a resistor arrangement space between the connection portion where the resistor is connected to the fixed contact portion and the resistor shield. desirable. Further, specifically, the resistor is configured by winding a resistance wire without induction, and furthermore, as the resistance wire, a coated resistance wire is used and can be closely wound. Usually, the resistor is
Plural pieces are arranged at equal intervals around the fixed side contact portion, and typically three pieces are arranged. According to the disconnector with a resistor of the present invention constructed as described above, since the resistor is formed by casting the resistance wire with the epoxy resin, the mechanical strength is increased by the epoxy resin. And a resistor having a sufficient mechanical strength can be obtained. Therefore, since the resistor itself and the resistor shield can be supported only by the resistor, it is not necessary to dispose a reinforcing insulating rod near the resistor. As one method for shortening the axial dimension of the fixed-side contact portion in the disconnector with resistance, a connection conductor derived from the fixed-side contact portion is arranged in the arrangement space of the resistor. Conceivable. In this case, when a ceramic resistor is used as the resistor as in the conventional example described above, in the resistor arrangement space, a large number of ceramic resistors and insulating rods are arranged at a narrow interval. It is essentially impossible to dispose a connection conductor derived from the fixed contact portion in this resistor disposition space. That is, as long as a ceramic resistor is used as the resistor, it is impossible to reduce the axial dimension of the fixed contact portion. On the other hand, in the present invention in which a resistor obtained by casting a resistance wire with epoxy resin is used as the resistor, the reinforcing insulating rod can be omitted as described above, so that the resistor is fixed. The dimension of the gap between the resistors in the space between the connection portion connected to the side contact portion and the resistor shield can be increased. Therefore, a connection conductor derived from the fixed contact portion can be arranged in this space. That is, since the resistor and the connection conductor can be arranged at the same position in the axial direction of the fixed-side contact portion, the axial dimension of the fixed-side contact portion can be significantly reduced as compared with the case where they are arranged at different positions in the axial direction. . An embodiment of the disconnector with resistor according to the present invention will be described below with reference to FIGS. 1, 3 and 4. In this case, FIG. 1 is a configuration diagram showing the entire disconnector, FIG. 3 is a view taken in the direction of the arrow X in FIG. 1, and FIG. 4 is a configuration diagram showing the resistor in FIG. First, the system of the disconnector with resistor according to the present embodiment is the same as the system of the disconnector with resistor described earlier with reference to the schematic diagram of FIG. 2, and the basic configuration thereof is shown in FIG. This is the same as the conventional example shown in FIG. That is, as shown in FIG. 1, in a tank 1 filled with SF ₆ gas, a movable contact portion 2 and a fixed contact portion 3 are arranged on a coaxial line in a vertical direction, and a movable contact 4 is provided therebetween. The disconnector is opened and closed by sliding linearly. The movable contact 4 is provided with an operating device 10 mounted on the upper part of the tank 1.
Thus, the rotational driving force of the operating device 10 is converted from a rotational motion to a linear motion by the opening / closing mechanism 11, and the movable contact 4
It is configured to be transmitted to. Further, the resistor shield 7 is disposed between the movable contact portion 2 and the fixed contact portion 3, and a resistance contact 8 is provided at an inner peripheral end thereof. The resistance contact 8 is configured to face the movable contact 4 via the gap g in the closed state. In this embodiment, as shown in FIGS. 1 and 3, below the outer peripheral end of the resistor shield 7, three downwardly extending resistors 9 are provided at the fixed contact portion 3. Are mounted at equal intervals around the periphery of the resistor 9, and are attached to the resistor shield 7.
Is attached to the fixed side contact portion 3. As shown in FIG. 4, the resistor 9 includes electrodes 9a and 9b provided at the upper and lower ends, and resistance wires 9c and 9d wound in opposite directions (accordingly, without induction). Line 9c,
9 d is entirely cast with an epoxy resin 9 e. In this case, the resistance wires 9c and 9d are coated with an insulating material, and the resistance wires 9c and 9d are wound in close contact with each other. In addition, one of the gaps between the resistors 9 in the space B between the resistor shield 7 in which these three resistors 9 are arranged and the connection portion 12 is led out from the fixed contact portion 3. The connection conductor 15 is disposed in the horizontal direction, and the insulating spacer 1
6 to the outside. The structure other than the resistor 9 and its surroundings is the same as that of the conventional example shown in FIG. That is, from the side surface of the movable contact portion 2, the connection conductor 14 is led out in the horizontal direction and is drawn out to the outside by the insulating spacer 16. The movable contact portion 2 and the fixed contact portion 3 are connected to the tank 1. The upper and lower ends are supported by insulating cylinders 13, respectively. The operation of this embodiment having the above configuration is as follows. That is, in this embodiment, since the resistor 9 is formed by casting the resistance wires 9c and 9d with the epoxy resin 9e, the mechanical strength is improved by the epoxy resin 9e, and the resistance of the conventional ceramic resistor 21 is increased. Can have a sufficiently high mechanical strength. Therefore, the resistor 9 itself and the resistor shield 7 can be supported by the resistor 9 alone, so that the insulating rod 22 required when the ceramic resistor 21 is used becomes unnecessary.
In addition, since the size of the resistor 9 itself can be significantly reduced as compared with the ceramic resistor 21, the size of the resistor 9 can be reduced.
The configuration in the vicinity can be significantly simplified as compared with the related art. In this embodiment, as described above, the reinforcing insulating rod 22 can be omitted in the space B between the resistor shield 7 and the connection portion 12, and the size of the resistor 9 itself can be reduced by ceramics. The size can be significantly reduced as compared with the resistor 21, and since only three resistors 9 are used,
The distance A between the resistors 9 can be widened, and as a result, as shown in FIG. It is possible to arrange in. That is, in the present embodiment, as shown in FIG. 1, the resistor 9 and the connection conductor 15 can be arranged at the same position in the axial direction of the fixed contact portion 3. The axial dimension of the fixed-side contact portion 3 can be remarkably reduced as compared with the case of disposing. Specifically, as apparent from a comparison between FIG. 5 and FIG. 1, the distance L ₁ (FIG. 1) between the resistor shield 7 and the connection conductor 15 in this embodiment is:
It is shortened remarkably as compared with the distance L ₂ of the same parts in the prior art. As described above, in this embodiment, by using the resistor 9 formed by casting the resistance wires 9c and 9d with the epoxy resin 9e, the resistance is sufficiently compared with the conventional ceramic resistor 21. Since high mechanical strength can be provided, the insulating rod 22 becomes unnecessary, and the resistor 9 itself can be reduced in size. As a result, the structure near the resistor 9 can be simplified. The simplification of the structure in the vicinity of the resistor 9 makes it possible to widen the space A between the resistors 9 and to dispose the connection conductor 15 in the space B. 3 can be shortened in the axial direction, thereby contributing to downsizing of the disconnector as a whole. Further, in this embodiment, since three resistors 9 are arranged, there is an advantage that the support structure is well balanced. The present invention is not limited to the above-described embodiment. For example, as the resistor, a resistor obtained by winding a resistance wire without insulation coating and casting it with an epoxy resin is used. It is also possible. Further, the number of resistors to be used is not limited to three, and can be appropriately selected. As described above, in the present invention,
By constructing the resistor by casting the entire resistor wire with epoxy resin, the mechanical strength of the resistor can be significantly improved compared to the conventional ceramic resistor, simplifying the structure near the resistor, It is possible to provide a disconnector with excellent resistance that can reduce the axial dimension of the fixed-side contact portion and contribute to downsizing and simplifying the entire disconnector.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing one embodiment of a disconnector with a resistor according to the present invention. FIG. 2 is a schematic diagram showing a method of the disconnector with a resistor shown in FIGS. 1 and 5; FIG. 3 is a view taken in the direction of the arrow X in FIG. FIG. 4 is a configuration diagram showing the resistor of FIG. 1; FIG. 5 is a configuration diagram showing an example of a conventional disconnector with a resistor. 6 is a configuration diagram showing the ceramic resistor of FIG. 5; FIG. DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Movable contact part 3 ... Fixed contact part 4 ... Movable contact 5,6 ... Finger 7 ... Resistance shield 8 ... Resistance contact 9 ... Resistor 9a, 9b ... Electrode 9c, 9d ... resistance wire 9e ... epoxy resin 10 ... operating device 11 ... opening and closing mechanism 12 ... connecting part 13 ... insulating cylinders 14 and 15 ... connecting conductor 16 ... insulating spacer 21 ... ceramic resistor 21a ... resistor 21b ... insulating bolt 22 ... insulating Rod A: Spacing B: Space

Claims (1)

(57) [Claim 1] A movable contact portion and a fixed contact portion are arranged on a coaxial line in a sealed container enclosing an insulating medium, and the movable contact portion and the fixed side are disposed. A movable contact is arranged between the contact portions, a resistor shield is arranged around the fixed contact portion, and the resistor shield is connected to the fixed contact portion via a resistor, A disconnector with a resistor that has a structure in which connection conductors are respectively led out from the movable contact portion and the fixed contact portion, and opens and closes an electric circuit by operating the movable contact. Characterized in that the entire resistance wire is cast with epoxy resin.