JPH05334942A - Disconnecting switch with resistor - Google Patents

Abstract

PURPOSE:To provide an excellent disconnecting switch with a resistor capable of adequately maintaining the electrical and mechanical strength of the resistor over a long term of operation stage after the stage of manufacture with high reliability and contributing to the reduction of the whole size of the device. CONSTITUTION:The contact part 2 of a movable side and the contact part 3 of a fixed side are arranged face to face, and a resistor 9 is provided in the circumferential part of the fixed-side contact part 3. The resistor wire of the resistor 9 is partially or entirely injection molded of epoxy resin. The cross section of the winding form of the resistor wire or the external shape of epoxy resin of the resistor wire is made in elliptical form, oblong form or partially modified elliptical form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnector with resistance used in a substation, and more particularly to a structure of the disconnector with resistance using a resistor having excellent electrical and mechanical reliability.

[0002]

2. Description of the Related Art Generally, a gas-insulated switchgear comprises a circuit breaker, a disconnector, a grounding switch, a current transformer, and a meter in a sealed container filled with an insulating medium such as SF ₆ gas at a pressure of 3 to 6 atmospheres. It is configured to house equipment necessary for opening and closing operations such as transformers. Among them, the opening / closing operation of the disconnecting switch is usually performed with the breaker opened. Along with such switching operation of the disconnecting switch, a surge called disconnecting switch surge is generated between the poles of the disconnecting switch and propagates in the gas-insulated switchgear. In the UHV class, this disconnector surge becomes so large as to threaten the insulation of the gas insulated switchgear, and therefore some measures must be taken.

Conventionally, for the purpose of suppressing the voltage level of such a disconnector surge, a disconnector with a resistor of the type as schematically shown in FIG. 4 has been considered.
As shown in this figure, a movable side contact portion 2 and a fixed side contact portion 3 are provided in a tank 1 filled with an insulating medium such as SF ₆ gas.
Are arranged on a coaxial line, the movable contact 4 is arranged between the contact portions 2 and 3, and the movable contact 4 slides linearly in the axial direction of the contact portions 2 and 3, It is configured to open and close the disconnector. 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. While being constantly in contact with the finger 5 of No. 3, the finger 6 of the fixed side contact portion 3 can be brought into contact with and separated from the finger 6.

A resistor shield 7 for mitigating an electric field is arranged around the fixed side contact portion 3, and between the movable contact 4 and the resistance contact 8 of the resistor shield 7 when the disconnector is turned on. To have a gap g. This gap g is defined by the resistance contact 8 and the movable contactor 4 when re-ignition occurs between the disconnector poles at the time when the tip of the movable contactor 4 is located near the resistance contact 8 during the opening / closing operation of the disconnector. Is energized by flashover, and at this time, the movable contactor 4 and the fixed side contact portion 3 and the tank 1 are determined by conducting an examination from the insulation emphasis surface so as not to cause dielectric breakdown. Further, the resistor shield 7 is connected to the fixed side contact portion 3 via the resistor 9 having a value capable of sufficiently suppressing the disconnector surge. During the opening / closing operation of the disconnector, re-ignition occurs a plurality of times between the movable contactor 4 and the resistance contact 8, but the disconnector surge level at this time is sufficiently suppressed by the resistor 9.

FIG. 5 is a block diagram showing an example of the configuration of a conventional disconnector with a resistor that employs the above-described system. As shown in this figure, a movable side contact portion 2 and a fixed side contact portion 3 are arranged coaxially in the up-down direction in a tank 1 filled with SF ₆ gas, and a movable contact 4 slides linearly between them. The disconnector is opened and closed by moving. Further, the resistor shield 7 is arranged between the movable side contact portion 2 and the fixed side contact portion 3, and a resistance contact 8 is provided at the inner peripheral side end portion thereof. The resistance contact 8 is configured to face the movable contact 4 with a certain gap in the closed state. A plurality of (two as an example in the figure) resistors 9 extending downward are arranged on the outer peripheral portion of the fixed side contact portion 3 below the outer peripheral side end portion of the resistor shield 7. The resistors 9 are attached to the shield 7, and the lower ends of these resistors 9 are attached to the fixed-side contact portion 3.

FIG. 6 is a diagram showing the configuration in the vicinity of the fixed side contact portion 3 in FIG. 5 and the distribution of the equipotential lines 10 when re-ignition occurs. That is, at the time of re-ignition, the surge voltage causes the potential of the resistance contact 8 to become higher than that of the fixed-side contact portion 3, so that a distribution of equipotential lines 10 as shown in FIG.
The electric field concentrates on the resistor 9. In this case, the material surface and the structural surface of the resistor 9 are currently being studied, but for example, use of a resistor using a resistance wire is considered.
FIG. 7 is a diagram showing an example of a resistor using such a resistance wire, (A) is a configuration diagram, and (B) is a sectional view. The resistor 9 shown in FIG. 7 is composed of a resistance wire 21 and electrodes 22 at both ends thereof. That is, the two resistance wires 21
Are wound around the insulating rod 23 in opposite directions, the electrodes 22 are drawn out from both ends of the insulating rod 23, and the electrodes 22 are fixed by an adhesive 24.

[0007]

By the way, since the disconnecting switch is a device that involves mechanical operation, it is considered that a large mechanical vibration occurs due to the opening and closing operation, and that the operation occurs frequently. It is very important to secure the electrical performance and mechanical strength of the resistor under such conditions for a long period of time. However, as shown in FIG. 7, when a resistor wire is used as the resistor element arranged around the fixed side contact portion, the mechanical strength of the resistor element itself and its long-term reliability are sufficient. Cannot be secured. If an adhesive is used to fix the resistance wire,
The electrical performance at the interface between the adhesive and the resistance wire or insulating rod may be reduced. Furthermore, during re-ignition, the electric field concentrates on the resistor as described above.To prevent the electrical performance from deteriorating due to this electric field concentration, the insulation distance between the resistor and the main circuit, and the insulation between the resistor and the tank There is also a problem that it is necessary to secure a sufficient distance, which hinders downsizing of the entire device.

The present invention has been proposed in order to solve the problems of the prior art as described above, and its purpose is to improve the electrical performance and mechanical strength of a resistor from a manufacturing stage to a long-term operation. It is possible to secure enough
It is to provide an excellent disconnecting switch with resistance that is highly reliable and can contribute to downsizing of the entire device.

[0009]

In the disconnector with resistance according to the present invention, a movable side contact portion and a fixed side contact portion are arranged so as to face each other in a sealed container in which an insulating medium is sealed, and the fixed side contact portion is provided. In a disconnecting switch with a resistance provided with a resistor in the outer peripheral part of the resistor, the resistor is formed by casting a part or the whole of the resistance wire in an epoxy resin, and the winding shape of the resistance wire or the cross section of the epoxy resin outer shape, It is characterized by an elliptical shape, an oval shape, or an elliptical deformed shape obtained by deforming a part of the ellipse.

[0010]

According to the disconnecting switch with resistance of the present invention constructed as described above, the resistance wire is cast by the epoxy resin to form the resistor, so that the epoxy resin has sufficient electric performance and mechanical properties. Since it is possible to secure the mechanical strength, it is possible to suppress the mechanical deterioration of the resistor and the accompanying deterioration of the electrical performance even with respect to a large mechanical vibration associated with the opening / closing operation of the disconnector. Therefore, it is possible to sufficiently secure the electrical performance and mechanical strength of the resistor for a long period of time even after the operation of the disconnector is started. Further, the winding shape of the resistance wire or the cross-section of the epoxy resin outer shape is formed into an elliptical shape, an oval shape, or an elliptical deformation shape, so that the electric field concentration on the resistor is alleviated and the equipotential lines are smoothed. Therefore, it is possible to reduce the insulation distance between the resistor and the tank and to reduce the size of the device while sufficiently ensuring the electrical performance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the disconnecting switch with resistance according to the present invention will be described below with reference to FIGS. In this case, FIG. 1 is a diagram showing the configuration in the vicinity of the fixed-side contact portion 3 and the distribution of the equipotential lines 10 when re-ignition occurs. 2 is a diagram showing a resistor, (A) is a configuration diagram,
(B) is a sectional view.

That is, as shown in FIG. 2, in the present embodiment, the resistor 9 has two resistance wires 21 wound in opposite directions, and the electrodes 22 are drawn out from both ends of the resistance wire 21. Is cast with an epoxy resin 25. The cross section of the winding shape of the resistance wire 21 of the resistor 9 and the outer shape of the epoxy resin 25 are both elliptical. Then, as shown in FIG. 1, the two resistors 9 having such a configuration are arranged on the outer peripheral portion of the fixed-side contact portion 3. Since the configuration of each part other than the resistor 9 is the same as that of the conventional example shown in FIG. 5, the description thereof is omitted here.

The operation of this embodiment having the above construction is as follows. First, since the epoxy resin can be made sufficiently thick as compared with the adhesive 24 in FIG. 7, even if mechanical stress is applied from the outside of the resistor 9, the internal resistance wire 21 is not broken or deformed. Also, as is well known, epoxy resin is a very excellent insulating material,
In terms of electrically insulating the resistance wire 21, it is superior to the configuration of the insulating rod 23 and the adhesive 24 shown in FIG. 7. Further, the epoxy resin casting technique is now established as an excellent technique capable of providing a high-quality epoxy resin casting product in which voids, cracks, and other weak points are eliminated by the remarkable technical development in recent years.

Therefore, by manufacturing the resistor 9 using such an excellent epoxy resin and its casting technique, there is no problem such as voids, peeling and cracks at the casting stage, and sufficient electrical conductivity is obtained. A resistor 9 having performance and mechanical strength can be obtained. When the disconnector is completed by using the resistor 9, mechanical deterioration of the resistor can be suppressed even with respect to a large mechanical vibration accompanying the opening / closing operation of the disconnector, and the operation is started. Even after that, the electrical performance and mechanical strength can be sufficiently ensured over the long term. Further, the winding shape of the resistance wire 21 and the epoxy resin 25
As shown in FIG. 1, the electric field concentration in the vicinity of the resistor 9 is relaxed and the equipotential lines 10 are smoothed by making both the outer shapes of the elliptical shapes. Therefore, it becomes possible to reduce the insulation distance between the resistor 9 and the tank 1 and to downsize the device as compared with the conventional one, while sufficiently ensuring the electrical performance.

As described above, in this embodiment, the entire resistance wire 21 is cast with the epoxy resin 25 to form the resistor 9, and the winding shape of the resistance wire 21 and the outer shape of the epoxy resin 25 are formed. By making both cross sections oval, the electrical performance and mechanical strength of the resistor can be sufficiently secured from the manufacturing stage to the long term after operation. -It is possible to significantly improve mechanical reliability as compared with the conventional one and contribute to downsizing of the entire device.

The present invention is not limited to the above embodiment, and for example, the winding shape of the resistance wire 21 and the outer shape of the epoxy resin 25 need not be elliptical in cross section. It is sufficient if the shape is an elliptical shape, an oval shape, or an elliptical deformed shape. Figure 3
It is sectional drawing which shows a different resistor used for other some Example of this invention. That is, first, in FIG.
The winding shape of the resistance wire 21 is circular, and the epoxy resin 25
Shows the resistor 9 in which only the outer shape of the resistor is oval,
Although the electric field relaxation effect is slightly inferior to that of the resistor 9 of FIG. 2 in which both have an elliptical shape, it is excellent in terms of facilitating manufacturing. Further, in FIG. 3B, contrary to FIG. 3A, only the winding shape of the resistance wire 21 has an elliptical shape, and the epoxy resin 25 is used.
2 shows a resistor 9 having a circular outer shape. The electric field mitigating effect is almost the same as that of the resistor 9 of FIG. 2 which is both elliptical, and improvement in mechanical strength can be expected.
Further, FIG. 3C shows a resistor 9 in which the cross section of the winding shape of the resistance wire 21 and the outer shape of the epoxy resin 25 are both oval, and FIG. The cross section of the winding shape of the resistance wire 21 and the cross section of the outer shape of the epoxy resin 25 are both substantially bow-shaped (the elliptical deformed shape in which the bending direction and the curvature of a part of the ellipse are changed). With these resistors 9 as well, it is possible to obtain substantially the same effects as the resistors 9 of FIG.

[0017]

As described above, according to the present invention,
By forming a resistor by casting a part or all of the resistance wire in epoxy resin, and making the winding shape of the resistance wire or the cross section of the epoxy resin outer shape an elliptical shape, an oval shape, or an elliptical deformation shape. With excellent resistance, it is possible to secure the electrical performance and mechanical strength of the resistor sufficiently from the manufacturing stage to the long term after operation, and it is highly reliable and can contribute to downsizing of the entire device. A disconnector can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration in the vicinity of a fixed side contact portion and a distribution of equipotential lines when re-ignition occurs in an embodiment of a disconnector with resistance according to the present invention.

2A and 2B are diagrams showing the resistor of FIG. 1, in which FIG. 2A is a configuration diagram and FIG. 2B is a sectional view.

FIG. 3 is a cross-sectional view showing different resistors used in other embodiments of the disconnecting switch with resistance according to the present invention.

FIG. 4 is a schematic diagram showing a system of a disconnecting switch with resistance.

5 is a configuration diagram showing an example of a disconnecting switch with resistance of FIG.

6 is a diagram showing a configuration in the vicinity of the fixed-side contact portion in FIG. 5 and a distribution of equipotential lines when re-ignition occurs.

7A and 7B are diagrams showing an example of a conventional resistor, in which FIG. 7A is a configuration diagram and FIG. 7B is a sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Movable side contact part 3 ... Fixed side contact part 4 ... Movable contactor 5,6 ... Finger 7 ... Resistor shield 8 ... Resistive contact 9 ... Resistor 10 ... Equipotential line 21 ... Resistance line 22 ... Electrode 23 ... Insulating rod 24 ... Adhesive 25 ... Epoxy resin

Claims (1)

[Claims] 1. A disconnecting switch with resistance, wherein a movable side contact portion and a fixed side contact portion are arranged to face each other in a hermetically sealed container in which an insulating medium is sealed, and a resistor is provided on an outer peripheral portion of the fixed side contact portion. In, the resistor is formed by casting a part or the whole of the resistance wire in an epoxy resin, and the winding shape of the resistance wire or the cross section of the epoxy resin outer shape is an elliptical shape, an oval shape, or a part of the ellipse is deformed. A disconnecting switch with resistance, which is characterized by having an elliptical deformed shape.