JPH08227624A - Voltage detecting insulator - Google Patents

Abstract

PURPOSE: To provide a large electrostatic capacity independently of the electrode structure, and to prevent the influence of noise by applying high voltage to one end of an insulator, connecting a control line to the other end of the insulator, and insulating an insulator fixing base, a control line and a grounding electrode. CONSTITUTION: A voltage detecting insulator 20 is formed of an insulating layer 21 formed by filling a mold with the insulating material such as epoxy resin, an upper electrode 22 embedded on the insulating layer, a lower electrode 23 embedded under the insulating layer 21, and a fixing fitting 24. The upper electrode 22 is formed with a screw part 25, and a main circuit base line is placed on the upper electrode 22, and the screw part 25 is screwed to the upper electrode 22 so as to connect the main circuit base line to the upper electrode 22. A control line 27 is fixed to the lower electrode 23 through a bolt 26. The control line 27 is connected to a detecting impedance. The insulator 20 is fixed to a box-type supporting unit 28 through the fixing fitting 24 embedded under the insulating layer 21. The fixing fitting 24, the control line 27 and the lower electrode 23 are electrically insulated. A mark L means the insulation distance of the voltage detecting insulator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage detecting insulator used in a gas insulated switchgear.

[0002]

2. Description of the Related Art In order to detect the presence or absence of a voltage applied to a main circuit bus of a gas insulated switchgear, a capacitor type voltage dividing circuit as shown in FIG. 4 is used. In this capacitor type voltage dividing circuit, a detection insulator 1 having a capacitance Ca is arranged in the primary capacitance, and the main circuit bus voltage V1 is divided between the detection insulator 1 and the detection impedance 2 to form a control circuit. Voltage V
You get 2.

As shown in FIG.
Ceramic capacitors 4a, 4b, 4c, 4 are provided inside an insulating layer 3 formed of a resin material such as epoxy resin.
It is configured by embedding d and 4e so as to be connected in series by a control line 5, and embedding an upper electrode 6 above the insulating layer 3 and a lower electrode 7 below the insulating layer 3. A screw part 8 is provided on the upper electrode 6, and a main circuit bus bar fixing means such as a screw is screwed onto the screw part 8 to connect a main circuit bus bar (not shown) to the upper electrode 6. A control line 10 is fixed to the lower electrode 7 via a bolt 9, and the control line 10 is connected to a detection impedance (not shown).

The electric detection insulator 1 has an embedded metal fitting 11 below an insulating layer 3 made of a resin material.
1 is arranged so as to be in contact with the inner surface of the box-shaped support portion 12, and is fixed to the box-shaped support portion 12 by screwing a bolt to the embedded metal fitting 11 through the opening of the box-shaped support portion 12.

FIG. 6 shows a non-contact type voltage detector utilizing a gas gap. This voltage detecting device forms a primary capacitance by disposing a disk-shaped electrode 14 facing the main circuit bus 13. The disk-shaped electrode 14 is fixed to the box body via an insulator 15, and the control line 16 extending from the lower part of the disk-shaped electrode 14 is connected to a detection impedance (not shown).

[0006]

[Problems to be Solved by the Invention]
Since the ceramic capacitor is embedded and cast in an insulating layer such as epoxy resin, the thermal stress generated during casting causes peeling at the boundary surface between the ceramic capacitor and the insulating layer, resulting in insulation from the ceramic capacitor. Microgaps are formed between the layers.

When a detection insulator having a minute gap formed between the ceramic capacitor and the insulating layer is used as the primary capacitance of the capacitor type voltage dividing circuit, partial discharge occurs in the minute gap portion of the detection insulator, The generated partial discharge may cause deterioration at the interface between the ceramic capacitor and the insulating layer, leading to dielectric breakdown between the ceramic capacitor and the insulating layer.

Further, in the electric detector using the gas gap, the electrostatic capacitance on the primary side is small, and the electrostatic capacitance greatly changes depending on the electrode structure, so that it takes time to adjust the secondary circuit. .

The present invention has been made in view of the above points, and it is an object of the present invention to provide an electric detection insulator that improves insulation reliability and does not require adjustment of a secondary circuit.

[0010]

According to a first aspect of the present invention, there is provided a galvanic insulator having two electrodes facing each other, and an insulating resin material cast to support the electrodes. Is applied, a control line is connected to the other end, and the insulator fixed base is insulated from the control line and the ground electrode.

According to a second aspect of the present invention, there is provided a voltage detecting insulator according to the first aspect, wherein a bell mouth is provided in the vicinity of the electrode of the insulating resin material casting.

According to a third aspect of the present invention, there is provided the electric insulator according to the second aspect, wherein the insulating resin material is a material having a high dielectric constant.

According to claim 4 of the present invention,
In an electric detection insulator in which two electrodes are opposed to each other and an insulating resin material is cast to support the electrodes, a discharge gap is provided between the high voltage side and the insulator ground.

[0014]

In the electric detection insulator of the present invention, peeling inside the electric detection insulator can be eliminated, and a large capacitance that does not change due to the electrode configuration can be obtained, insulation reliability is improved, and adjustment of the secondary circuit is unnecessary. Become.

Further, in the galvanic insulator of the present invention, the insulating layer is formed of a material having a high dielectric constant, and the bell mouth is provided in the vicinity of the electrode of this insulating layer, whereby the withstand voltage performance is improved and the insulating distance is reduced. By doing so, a larger capacitance can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing a cross section of a half of an electromotive insulator according to the present invention. The electromotive insulator 20 includes an insulating layer 21 cast with an insulating material such as epoxy resin, and this insulating layer. The upper electrode 22 is buried in the upper part of the insulating layer 21, and the lower electrode 23 and the fixing metal piece 24 are buried in the lower part of the insulating layer 21. The upper electrode 22 has a threaded portion 2
5 is formed, a main circuit bus bar (not shown) is placed on the upper electrode 22, and a screw (not shown) is screwed into the screw portion 25 provided on the upper electrode 22 to connect the main circuit bus bar to the upper electrode 22. It A control line 27 is fixed to the lower electrode 23 via a bolt 26. The control line 27 is connected to a detection impedance (not shown). The electromotive insulator 20 is fixed to the box-shaped support portion 28 via a fixing metal fitting 24 embedded in the lower portion of the insulating layer 21.

That is, the fixing member 24 (insulator fixing base), the control line 27, and the ground electrode 23 are electrically insulated.

In FIG. 1, the symbol L indicates the insulation distance of the voltage detector insulator.

Therefore, the voltage detecting insulator 20 according to the present invention
4 is arranged in a voltage dividing circuit as shown in FIG. 4 to detect whether or not the main circuit bus of the gas-insulated switchgear is energized, there is no ceramic capacitor inside the electric detection insulator 20. There is no peeling that would cause dielectric breakdown between the capacitor and the insulating layer, a large capacitance that does not change due to the electrode configuration can be obtained, and the secondary current can be detected without being affected by noise. Become.

2 and 3 show another embodiment of the present invention. In the electric insulator insulator 30 of the embodiment shown in FIG. 2, only the structure of the insulating layer 31 is different from that of the electric insulator insulator 20 of FIG. Are different.

That is, the voltage detecting insulator 30 shown in FIG.
A bell mouth 32 is provided near the upper electrode 22 of the insulating layer 31, a bell mouth 33 is provided near the lower electrode 23 of the insulating layer 31, and a conductive material paint 34 is applied to the inside of each bell mouth 32, 33. Is configured.
In FIG. 1, reference numeral L1 indicates the insulation distance of the electromotive insulator.

In this way, the insulating layer 31 of the galvanic insulator 30
By providing the bell mouths 32 and 33 in the vicinity of the upper electrode 22 and the lower electrode 23, the electric field is relieved, the withstand voltage value is improved, and the insulation distance L1 of the electromotive insulator 30 is equal to that of the electromotive insulator 20 of FIG. Is smaller than the insulation distance L, the capacitance is large, and the secondary current can be detected without being buried in noise or the like.

By using an insulating material having a high dielectric constant as the insulating material of the insulating layer 31, a larger capacitance can be obtained and adjustment of the secondary circuit is possible.

In the embodiment shown in FIG. 3, the voltage detecting insulator 30 shown in FIG. 2 is used to protect the detection circuit. In this embodiment, the box-shaped support portion 28 of the voltage detecting insulator 30 is used. The detection circuit (not shown) is configured to be independent from the ground, and the box-shaped support portion 28 side is grounded with a discharge gap 40.

As described above, the discharge gap 40 is provided in the ground on the side of the box-shaped support portion 28, so that the withstand voltage of the gas space is made lower than that of the detection circuit. Prevent overcurrent in the circuit and protect the detection circuit.

[0027]

As described above, according to the present invention, it is possible to obtain a large electrostatic capacitance that does not change due to the electrode configuration, eliminating the peeling inside the detection insulator, and preventing the secondary current from being affected by noise. Can be detected, and the reliability of the device is improved.

Further, by forming the insulating layer of the voltage detector insulator with a material having a high dielectric constant and providing the bell mouth in the vicinity of the electrodes, the withstand voltage performance is improved and the overall structure can be made compact.

[Brief description of drawings]

FIG. 1 is a side view showing a cross section of a part of an electric insulation insulator according to the present invention.

FIG. 2 is a view showing another embodiment of the voltage detecting insulator according to the present invention.

FIG. 3 is a diagram showing an example in which the voltage detection insulator shown in FIG. 2 is used for protection of a voltage detection circuit.

FIG. 4 is a diagram showing a usage example of a voltage detecting insulator.

FIG. 5 is a cross-sectional view of a conventional galvanic insulator.

FIG. 6 is a diagram showing a conventional non-contact type voltage detector.

[Explanation of symbols]

 20 Electrostatic insulator 21 Insulating layer 22 Upper electrode 23 Lower electrode 27 Control line L Insulating insulator insulation distance

Claims (4)

[Claims] 1. An electromotive insulator in which two electrodes are opposed to each other and an insulating resin material is cast to support the electrodes. A high voltage is applied to one end and a control line is connected to the other end of the insulator. An electric insulation insulator characterized by insulating the control line and the ground electrode. 2. A voltage detecting insulator according to claim 1, wherein a bell mouth is provided in the vicinity of the electrode of the insulating resin material casting. 3. The voltage detector insulator according to claim 2, wherein the insulating resin material is a material having a high dielectric constant. 4. An electric detection insulator in which two electrodes are opposed to each other and an insulating resin material is cast to support the electrodes, and a discharge gap is provided between the high voltage side and the insulator ground. .