JPH08211107A - Optical voltage measuring device for gas-insulated electrical equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To propose an optical voltage measuring device for gas-insulated electrical equipment that can measure voltage with higher accuracy and is easy to maintain. A ground electrode 20 attached to the container 10 at a predetermined distance from the bus bar 11 housed in the container 10 and having a hole 21 in a part of a portion facing the bus bar 11, and a bus bar of the ground electrode 20. The hole 2 of the ground electrode 20 on the back side with respect to 11
1. The intermediate electrode 30 facing the No. 1 and arranged at a predetermined interval.
Gas insulation including an optical voltage sensor 40 connected to the intermediate electrode 30 and the ground electrode 20, and a signal processing device 50 disposed outside the container 10 and optically connected to the optical voltage sensor 40. In the optical voltage measuring device for electric equipment, the optical voltage sensor 40 is connected to the ground electrode 20 and the intermediate electrode 3.
The electrode 46 of the electro-optic crystal 44 which is disposed between the ground electrode 20 and the intermediate electrode 3 and is arranged between the ground electrode 20 and the intermediate electrode 3
0 and 0 are directly contacted and connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical voltage measuring device for measuring an earth-to-ground voltage of a bus bar by utilizing an electro-optical effect in a gas-insulated electric device such as a gas-insulated switchgear.

[0002]

2. Description of the Related Art FIG. 9 shows an example of the configuration of an optical voltage sensor using a lateral optical modulation method such as lithium niobate in an optical voltage measuring apparatus utilizing the electro-optical effect.

The optical voltage sensor comprises a polarizer 42, a quarter-wave plate 43, an electro-optic crystal 44, and an analyzer 45 in the order of the optical path 41. Also, the polarizer 42 and the analyzer 4
The light input / output unit of 5 is condensed by the collimator lens 47. Electrodes 46 are vapor-deposited on two opposite surfaces that are parallel to the optical path of the electro-optic crystal 44.

When a voltage to be measured is applied to the electrode 46, the electro-optic crystal 44 changes its refractive index according to the applied voltage due to the electro-optic effect. This change in the refractive index shows different values depending on the X and Y directions.

The light incident along the optical path 41 is reflected by the polarizer 42.
After being converted into linearly polarized light by, the quarter-wave plate 43 becomes circularly polarized light. Next, this circularly polarized light is phase-modulated by passing through the electro-optic crystal 44 to which a voltage is applied and becomes elliptically polarized light. Since the intensity of this elliptically polarized light is converted by the analyzer 45, the voltage applied to the electro-optic crystal 44 can be measured as the light intensity.

The voltage that can be measured by the optical voltage sensor is about several hundred volts. Therefore, when measuring a high voltage with an optical voltage sensor, the measured voltage is divided, and after this divided voltage is measured with an optical voltage sensor,
A method of calculating the measured voltage by a known voltage division ratio is used.

FIG. 8 shows a conventional optical voltage measuring device for measuring the earth-to-ground voltage of a bus bar 11 of a gas-insulated electric apparatus by using this optical voltage sensor.

A disk-shaped intermediate electrode 30 is installed inside the grounded cylindrical container 10 of the gas-insulated electric equipment so as to face the front end surface of the bus bar 11. The front end surface of the bus bar 11 and the intermediate electrode 30 are connected to each other. A ground electrode 20 having a hole 21 in a portion facing the bus bar 11 is arranged between the two. The ground electrode 20 is fixed to the container 10 and has the same potential as the container 10. The intermediate electrode 30 is fixed to the ground electrode 20 by a support 25 made of an insulating material. The optical voltage sensor 40 is the container 1
It is fixed inside 0. The electrode 46 of the optical voltage sensor 40, the intermediate electrode 30, and the ground electrode 20 are connected to each other by lead wires 31 and 32. Further, the signal processing device 50 is arranged outside the container 10, and is optically connected to the optical voltage sensor 40 via the optical fiber 51 for light transmission and the optical fiber 52 for light reception via the sealed terminal 12.

When a voltage is applied to the bus bar 11, an electric field is generated between the bus bar 11 and the ground electrode 20. Since the ground electrode 20 is provided with the hole 21, the size of the hole 21 and the bus bar 1
1, the distance between the ground electrode 20 and the ground electrode 20, the ground electrode 20 and the intermediate electrode 3
A voltage having a magnitude corresponding to the distance from 0 is generated between the ground electrode 20 and the intermediate electrode 30. This voltage is
It is applied to the optical voltage sensor 40 by 32.

This voltage is the electrostatic voltage CS between the bus 11 and the ground electrode 20, the electrostatic capacitance CT between the bus 11 and the intermediate electrode 30, and the optical voltage. It is obtained by being divided by the capacitance CK of the sensor.

Since the voltage that can be measured by the optical voltage sensor 40 is several hundred volts as described above, the intermediate electrode 30
The voltage generated between the ground electrode 20 and the ground electrode 20 is adjusted to be several hundred volts. This adjustment is performed by adjusting the height H of the support base 25 and changing the distance between the ground electrode 20 and the intermediate electrode 30 in order to change the above-mentioned electrostatic capacitances CS and CT.

The voltage applied to the optical voltage sensor 40 is converted into the intensity of light by the above-mentioned means, and sent to the signal processing device 50 through the sealed terminals 12 by the optical fibers 51 and 52.

In the signal processing device 50, the intensity of light is converted into a current signal by a photodiode, and then converted into a voltage signal using a resistor, and a known voltage division ratio is added to the voltage signal to integrate the bus 1
It displays and outputs the voltage across the earth applied to 1.

[0014]

However, in the conventional optical voltage measuring device, the capacitance formed by the lead wires 31 and 32 is determined by the geometrical arrangement of the bus bar 11, the ground electrode 20 and the intermediate electrode 30 described above. In addition to causing an error in the voltage division ratio, this error causes the lead wires 31 and 32 to be manufactured.
However, there is a problem that it is not fixed for each individual. Further, the hole 21 provided in the ground electrode 20 is
Since the side is in communication with the optical voltage sensor 40 side,
In the case of removing only the optical voltage sensor 40 side, there is a problem that maintenance is not easy because it requires work such as removing the insulating gas sealed in the gas-insulated electric device main body side having the busbar 11. . It is therefore an object of the present invention to provide an optical voltage measuring device for a gas-insulated electric device, which eliminates such a problem and can measure a voltage with higher accuracy and is easy to maintain.

[0015]

According to a first aspect of the present invention, a gas-insulated electric device is attached to a container at a predetermined distance from a busbar housed in the container, and a hole is provided in a part of a portion facing the busbar. Ground electrode, an intermediate electrode facing the hole of the ground electrode on the back side of the bus bar of the ground electrode, and arranged at a predetermined interval, and an optical type electrode connected to the intermediate electrode and the ground electrode. An optical voltage sensor for a gas-insulated electric device, comprising: a voltage sensor; and a signal processing device arranged outside the container of the gas-insulated electric device and optically connected to the optical voltage sensor. Is disposed between the ground electrode and the intermediate electrode, and the electrode of the electro-optical crystal of the optical voltage sensor is directly contacted with and connected to the ground electrode and the intermediate electrode, respectively.

According to another aspect of the present invention, there is provided a grounding electrode, which is attached to the container at a predetermined distance from the busbar housed in the container of the gas-insulated electric equipment and has a hole in a part of a portion facing the busbar.
On the back side of the bus bar of the ground electrode, an intermediate electrode facing the hole of the ground electrode and arranged at a predetermined interval, an optical voltage sensor connected to the intermediate electrode and the ground electrode, and a gas. An optical voltage measuring device for gas insulated electrical equipment, which is disposed outside a container of insulated electrical equipment, and which includes a signal processing device optically connected to the optical voltage sensor, in the ground electrode of the intermediate electrode. On the back side, the optical voltage sensor is arranged such that one of the electrodes of the electro-optic crystal is in contact with the electrode, and the other of the electrodes of the electro-optic crystal is in contact with the other of the ground electrode or the gas-insulated electrical equipment. A grounding plate attached to the container is provided.

According to a third aspect of the present invention, the ground electrode is arranged so as to face the tip of the bus bar, and the hole is provided at the portion facing the tip of the bus bar.

According to a fourth aspect of the present invention, the ground electrode is the side wall of the container of the gas-insulated electrical equipment corresponding to the long axis direction of the bus bar, and a hole facing the bus bar is provided in a part of this side wall.

According to a fifth aspect of the present invention, the ground electrode is arranged so as to face the tip portions of the three-phase busbars, holes are provided at the portions facing the respective tip portions of the three-phase busbars, and the three phases are defined. A metal barrier having a length is provided on the bus bar side.

According to a sixth aspect of the present invention, an insulating blind lid for hermetically sealing the hole provided in the ground electrode is provided.

[0021]

In the optical voltage measuring device for gas-insulated electrical equipment according to the present invention as defined in claim 1, 2, 3, 4 or 5, the voltage generated between the intermediate electrode and the ground electrode is read. Since the line is not required and is directly applied to the electro-optic crystal of the optical voltage sensor, the voltage can be accurately measured without being affected by the capacitance of the lead wire.

Further, in the structure of the present invention as set forth in claim 6, the insulating gas sealed in the main body side of the gas-insulated electric device having the bus bar and the insulating gas sealed in the optical voltage sensor side are covered with a blind cover. Since it is divided by, it is not necessary to remove the insulating gas from the entire gas-insulated electrical equipment when attaching and detaching only the optical voltage sensor unit.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an example of an optical voltage measuring device for gas insulated electrical equipment according to the present invention. As shown in FIG. 1 (A), a busbar 11 of the gas insulated electrical equipment is supported on a container 10 by a spacer 12. There is. The ground electrode 20 faces the tip of the bus bar 11 and is attached to the container 10 at a predetermined distance from the tip. This attachment can be done by welding directly to the container 10 or by detachably attaching a flange in the container 10 and bolting it. A hole 21 of a required size is provided in a portion of the ground electrode 20 facing the tip of the busbar 11, and an intermediate electrode 30 is attached to the hole 21 via a support 25 of an insulator. This attachment may be adhesive bonding, but may be attached to the ground electrode 20 with an insulating bolt for the sake of reliability. The support 25 and the intermediate electrode 30 are preferably disk-shaped.

The support base 25 has a notch, and the optical voltage sensor 40 is embedded in the notch as shown in FIG. 1 (B). As described above, the optical voltage sensor 40 includes the collimator lens 47, the polarizer 42, and the 1/4.
The wavelength plate 43, the electro-optic crystal 44, the analyzer 45, and the collimator lens 47 are arranged in this order. To embed the optical voltage sensor 40 in the support 25, the electro-optical crystal 44 is used.
The electrodes 46 on both surfaces are arranged so as to contact the ground electrode 20 and the intermediate electrode 30, respectively. For contacting the electrodes 46 on both sides with the ground electrode 20 and the intermediate electrode 30, the thickness of the support base 25 may be matched with the thickness of the electro-optical crystal 44, but the ground electrode 20, the intermediate electrode 30, and the electro-optical crystal 30. The crystal 44 may be brought into contact with the crystal 44 via a highly conductive spring.

Optical fibers 51 and 52 are respectively connected to the two collimator lenses 47 of the optical voltage sensor 40, and the optical fibers 51 and 52 are connected to each other via a sealed terminal 12 attached to the container 10 as shown in FIG. It is connected to the processing device 50. The cover 13 is bolted to the container 10, and the optical voltage sensor 40 is sealed in the insulating gas by the cover 13.

The light sent from the signal processing device 50 to the optical fiber 51 is returned from the optical fiber 52 to the signal processing device 50 through the optical voltage sensor 40. As described above, when a voltage is applied to the bus bar 11, a voltage divided between the intermediate electrode 30 and the ground electrode 20 is generated by the electric field, and this voltage is directly applied to the electro-optic crystal of the optical voltage sensor 40. It is applied to 44 and converted into an optical signal. As a result, the signal processing device 50 can output the voltage between the earth applied to the bus bar 11 from the received optical signal using a known voltage division ratio.

FIG. 2 shows another embodiment of the present invention in which the intermediate electrode 30 described above is fixed by a support 26 of an insulator attached to the cover 13, and the optical voltage sensor 40 is shown in FIG. Similar to the above case, the electrodes of the electro-optic crystal 44 are arranged so as to be in contact with the intermediate electrode 30 and the ground electrode 20, respectively.

FIG. 3 shows another embodiment of the present invention.
In (A), the bus bar 11 and the ground electrode 20 have the same configuration as the above case. The intermediate electrode 30 is attached to the rear side of the bus bar 11 of the ground electrode 20 by the support 25 so as to face the hole 21. As shown in FIG. 3B, the optical voltage sensor 4 is provided on the back side of the ground electrode 20 of the intermediate electrode 30.
0 is arranged such that one of the electrodes 46 on both surfaces of the electro-optic crystal 44 is in contact with the intermediate electrode 30. Further, the intermediate electrode 3 is brought into contact with the other electrode 46 of the electro-optic crystal 44.
A grounding plate 23 having a U-shaped cross section having a size not contacting 0 is provided. The ground plate 23 is attached to the ground electrode 20 at a tip portion having a U-shaped cross section.

The electro-optical crystal 44 constituting the optical voltage sensor 40 may be brought into direct contact with the intermediate electrode 30 and the ground electrode 23, but the same as in the above-described embodiment. It is also possible to make contact with each other through a highly conductive leaf spring. Further, in this embodiment, the ground plate 23 has a U-shaped cross section and is attached to the ground electrode 20 so as to cover the intermediate electrode 30, but it may be attached to the cover 13 in a reverse direction although not shown. In this case, the intermediate electrode 30 may be attached to the ground plate 23 side via an insulator. In this configuration, when a voltage is applied to the bus bar 11,
As in the case described above, a divided voltage is generated between the ground electrode 20 and the intermediate electrode 30, but since the ground plate 23 and the ground electrode 20 have the same potential, the optical voltage sensor 40
The divided voltage will be applied to.

Therefore, as described above, the signal processing device 50
The light emitted from the optical fiber 51 is collimated by the collimator lens 47, the polarizers 42, 1 of the optical voltage sensor 40.
The / 4 wavelength plate 43, the electro-optic crystal 44, the analyzer 45, and the collimator lens 47 are passed through to obtain an optical intensity signal of voltage, and the optical intensity signal is returned to the signal processing device 50 via the optical fiber 52. With this, the voltage between the ground of the bus bar 11 can be measured.
It is similar to the above case.

FIG. 4 shows another embodiment of the present invention in which the ground electrode and the side wall of the container 10 corresponding to the longitudinal direction of the bus bar 11 are shared. A hole 21 is provided on the side wall of the container 10 corresponding to the long axis direction of the bus bar 11 so as to face the bus bar 11. The hole 21 is centered on the outside of the container 10 in the same manner as in the above-described example, the intermediate electrode 30 and the support 25. , Optical voltage sensor 4
0 is arranged. Although the container 10 is generally cylindrical, it can be mounted in the same manner as in the above example because of the small number of optical voltage sensors 40 compared to its curvature.

The cover 13 is attached to the cylindrical portion of the container 10 via an adapter (not shown), and the portion of the optical voltage sensor 40 is sealed in an insulating gas. Further, the hermetically sealed terminal 12 is attached to the cover 13, and the signal processing device 50 and the optical voltage sensor 40 are connected by the optical fibers 51 and 52 as in the above-described example. When a voltage is applied to the bus bar 11, a divided voltage is generated between the intermediate electrode 30 and the container 10, whereby the bus bar 11 is generated.
The ground voltage of can be measured as in the above case.

FIG. 5 shows an example in which the structure shown in FIG. 4 is applied to a three-phase bus bar. Three-phase bus 11a, 11
b, 11c on the side wall of the container 10 corresponding to the long axis direction, holes 21a, 21b, 2 are respectively formed on the portions corresponding to the surfaces of the three-phase bus bars 11a, 11b, 11c closest to the side wall.
1c is provided. Other configurations are the same as those shown in FIG.

In this configuration, the optical voltage sensors 40a, 40b, 40c arranged corresponding to the respective phases measure the voltage based on the electric field combined with the electric fields of the other phases. This measured value and the buses 11a, 11b, 11c, and the container 1
The ground voltage of each phase can be calculated from the ratio obtained in advance by the electric field calculation by the geometrical arrangement of 0 and the intermediate electrodes 30a, 39b, 30c. However, in this embodiment, the influence of the electric field of the other phase is negligibly small.

FIG. 6 shows still another embodiment of the present invention. FIG. 6 shows an example in which the configuration shown in FIG. 1 is applied to a three-phase bus. As shown in the figure, the ground electrode 20 includes a main plate 20a and bus bars 11a, 11 perpendicular to the main plate 20a.
and a barrier 20b attached so as to geometrically divide the busbars 11a, 11b, 11c on the sides b, 11c, and the main plate 20a has busbars 11a, 11b.
The holes 21 are provided at the portions corresponding to the tips of b and 11c.
a, 21b, 21c are provided. Others are the same as the above-mentioned composition. That is, these holes 21a, 21b, 21c
On the back surface of the intermediate electrodes 30a, 30b, which are arranged so that the holes 21a, 21b, 21c are at the center, respectively.
An optical voltage sensor 40a between the main plate 20a and 30c,
40b and 40c are provided. In this configuration,
Optical voltage sensors 40a, 40 arranged corresponding to each phase
Voltages based on the electric fields combined with the electric fields of the other phases are measured from b and 40c. In this case as well, the ground voltage of each phase is calculated in the same manner as in the embodiment shown in FIG. can do.

In this embodiment, the influence of the other phase is in a practically permissible range even when the barrier 20b is not attached.

In FIG. 7, a region having an insulating gas on the gas-insulated electric device main body side including the bus bar 11 and a region having an insulating gas including the optical voltage sensor 40 are divided.
It is another embodiment of the present invention. In the figure, the hole 21 provided in the ground electrode 20 is sealed by a blind lid 60 made of an insulating material on the side having the optical voltage sensor 40. This sealing can be performed by providing a tap hole that does not penetrate the ground electrode 20 and tightening the blind lid 60 with an insulating bolt.

A general gasket structure or an O-ring 61 as shown in the figure may be used for hermetically sealing the insulating gas. However, the ground electrode 20 often does not maintain perfect flatness, and thus the complete sealing is achieved. Therefore, the tightening structure at the flange portion between the container 10 and the cover 13 is required as a completely airtight structure for the insulating gas. The structure of the blind lid 60 has an effective effect that the insulating gas on the gas-insulated electric equipment main body side does not have to be vented in the usual maintenance work of the optical voltage sensor 40 in a short time.

[0039]

According to the present invention, since the voltage generated at the intermediate electrode and the ground electrode can be directly applied to the optical voltage sensor without requiring the lead wire, the unstable capacitance change caused by the lead wire is prevented. Without it, the voltage can be measured accurately. In addition, the insulating gas flow path of the insulating gas between the gas-insulated electrical equipment side and the optical voltage sensor side is sealed to remove the insulating gas from the gas-insulated electrical equipment when mounting or removing the optical voltage sensor side. The maintenance of the optical voltage sensor becomes very easy because it is not required.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an optical voltage measuring device for gas-insulated electrical equipment according to the present invention, in which (A) is a cross-sectional view of a mounting portion, and (B).
[Fig. 4] is a view of a support base.

FIG. 2 is a diagram showing another example of the optical voltage measuring device for gas-insulated electrical equipment of the present invention.

3A and 3B are views showing still another example of the optical voltage measuring device for gas-insulated electrical equipment according to the present invention, in which FIG. 3A is a sectional view of a mounting portion, and FIG. 3B is an enlarged view of the mounting portion of the optical voltage sensor. Is.

FIG. 4 is a diagram showing still another example of the optical voltage measuring device for gas-insulated electrical equipment of the present invention.

FIG. 5 is a diagram showing still another example of the optical voltage measuring device for gas-insulated electrical equipment of the present invention.

FIG. 6 is a diagram showing still another example of the optical voltage measuring device for gas-insulated electrical equipment of the present invention.

FIG. 7 is a diagram showing still another example of the optical voltage measuring device for gas-insulated electrical equipment of the present invention.

FIG. 8 is a diagram showing an example of a conventional optical voltage measuring device for gas-insulated electrical equipment.

FIG. 9 is a diagram showing an example of a configuration of an optical voltage sensor.

[Explanation of symbols]

 10 Container 11 Busbar 13 Cover 20 Grounding Electrode 21 Hole 23 Grounding Plate 30 Intermediate Electrode 40 Optical Voltage Sensor 44 Electro-Optical Crystal 46 Electrode 50 Signal Processing Device

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akira Ito 3-1, Yoshino-cho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Takatake Manufacturing Co., Ltd. Technology Development Center

Claims (6)

[Claims] 1. A grounding electrode which is attached to a container at a predetermined distance from a bus bar housed in a container of a gas-insulated electric device and has a hole in a part of a portion facing the bus bar, and a bus bar of this ground electrode. On the other hand, on the back side, an intermediate electrode facing the hole of the ground electrode and arranged at a predetermined interval, an optical voltage sensor connected to the intermediate electrode and the ground electrode, and a container for gas-insulated electrical equipment. An optical voltage measuring device for a gas-insulated electrical device, which is arranged outside and comprises a signal processing device optically connected to the optical voltage sensor, wherein an optical voltage sensor is provided between the ground electrode and the intermediate electrode. And an electrode of an electro-optical crystal of the optical voltage sensor is directly contacted with and connected to the ground electrode and the intermediate electrode, respectively, and an optical voltage measuring device for gas insulated electrical equipment. 2. A ground electrode which is attached to the container at a predetermined distance from the bus housed in the container of the gas-insulated electric equipment and has a hole in a part of a portion facing the bus bar, and a bus bar of the ground electrode. On the other hand, on the back side, an intermediate electrode facing the hole of the ground electrode and arranged at a predetermined interval, an optical voltage sensor connected to the intermediate electrode and the ground electrode, and a container for gas-insulated electrical equipment. An optical voltage measuring device of a gas-insulated electric device, which is arranged outside and includes a signal processing device optically connected to the optical voltage sensor, wherein the intermediate electrode has a rear surface with respect to the ground electrode, the optical Type voltage sensor is arranged such that one of the electrodes of the electro-optical crystal is in contact with the electrode, and the grounding plate is attached to the ground electrode or the container of the gas-insulated electric device so as to be in contact with the other electrode of the electro-optical crystal. Was established An optical voltage measuring device for gas-insulated electrical equipment, characterized by: 3. The optics for gas-insulated electrical equipment according to claim 1, wherein the ground electrode is arranged so as to face the tip of the busbar, and a hole is provided at a portion facing the tip of the busbar. Voltage measuring device. 4. The ground electrode according to claim 1 or 2, wherein the ground electrode is a side wall of the container of the gas-insulated electrical equipment corresponding to the long axis direction of the bus bar, and a hole is provided in a part of this side wall facing the bus bar. An optical voltage measuring device for gas-insulated electrical equipment. 5. The ground electrode according to claim 1 or 2, wherein the ground electrode is arranged so as to face the tip portions of the three-phase busbars, and holes are provided at the portions facing the respective tip portions of the three-phase busbars. An optical voltage measuring device for gas-insulated electrical equipment, characterized in that a metal barrier having a predetermined length is provided on the bus bar side for partitioning. 6. The optical system for gas-insulated electrical equipment according to claim 1, further comprising an insulating blind lid for hermetically sealing a hole provided in the ground electrode. Voltage measuring device.