JPH09261813A - Gas insulated switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GIS capable of easily detecting the voltage in a GIS container. SOLUTION: In a shield 2 of a wire wound current transformer arranged in a GIS container, a notch opposed to a conductor 4 is provided, here, an electrode 5 opposed to the conductor is provided. Since a stray capacitance 7 appears between the electrode and the conductor, a divider capacitor 8 is connected between the electrode and the earth, voltage between both ends of the divider capacitor is detected by a means 9, so as to measure the voltage of the conductor. Further, this electrode is formed in a separate unit from the shield, the electrode can be mounted outside the shield. This voltage detection part 50 can be provided in a conventionally existing current transformer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear, and more particularly to a gas insulated switchgear (hereinafter referred to as "GIS") capable of detecting the voltage of a conductor inside a container.
It is about.

[0002]

2. Description of the Related Art A conventional GIS will be described with reference to FIG. FIG. 9 shows a single-line connection diagram of a conventional GIS unit. In the figure, 21 is a busbar container, 22 is a circuit breaker container,
Reference numeral 23 is a cable head container, and 24 is a lightning arrester container that houses the lightning arrester 17.

Here, in order to measure or detect the voltage in the circuit breaker container 22, it is preferable to house a voltage transformer in the circuit breaker container 22. However, the conventional wire-wound voltage transformer cannot be housed inside the breaker container 22 due to its large shape, so that the voltage transformer 1 may be installed in the cable head container 23 or the like.
8 was provided.

[0004]

However, in the above configuration, when the disconnector 13 inserted between the breaker 12 and the voltage transformer 18 is opened, the voltage inside the breaker container 22 cannot be measured. . In addition, when the disconnectors 11 and 13 connected to both ends were opened for inspection of the circuit breaker 12, it was not possible to easily perform voltage detection inside the circuit breaker container 22.

An object of the present invention is to provide a GIS capable of easily detecting the voltage inside the GIS container.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. The present invention is directed to a gas insulated switchgear having a wire wound current transformer arranged around a conductor and having a shield between the conductor and the conductor. For detection of the conductor voltage, that is, for voltage measurement or voltage detection, a cutout is formed in a part of the shield facing the conductor of the current transformer, and an electrode is provided in the cutout. A means for detecting a voltage is provided between this electrode and the ground.

The first means for detecting this voltage is
There is a method in which a voltage dividing capacitor is connected between the electrode and the ground and the voltage of the voltage dividing capacitor is measured to measure the voltage of the conductor. It measures the stray capacitance existing between the electrode and the conductor and the voltage divided by the voltage dividing capacitor. Secondly, there is a device in which an impedance element or the like is connected between the electrode and the ground to detect a leak current flowing through the impedance element. This measures the leakage current generated by the stray capacitance appearing between the electrode and the conductor to detect the conductor.

According to another aspect of the present invention, instead of forming a notch for providing an electrode on the shield of the current transformer, a ring-shaped electrode facing the conductor is separately formed, and this is used for the current transformer. It can also be arranged side by side at the end. in this case,
The electrodes can be easily removed when voltage detection is not performed.

[0009]

Embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows a structure of a current transformer incorporating electrodes for voltage detection, (a) is a plan view, and (b) is a side sectional view taken along line AA of (a). The figure is shown. Further, FIG. 2 shows a circuit configuration of the voltage detecting portion.

In FIG. 1, 4 is a conductor, and 14 is a wire wound current transformer arranged around the conductor 4. This current transformer 14 includes a shield 1 whose current transformer body 3 is at ground potential.
It has a structure covered by 2. The above structure is the same as that of the conventional current transformer. In this example, in order to detect the voltage of the conductor 4, a notch is provided in a part of the shield 2 facing the conductor 4, and the plate-shaped electrode 5 is arranged in this notch. The electrode 5 is attached while being electrically insulated from the shield 2. Details of the structure will be described later. The shape of the electrode 5 may be square, circular, or the like. Further, it may be a flat plate or one having a curvature according to the surface shape of the conductor 4.

In this example, the electrode 5 is used to measure the voltage of the conductor 4. FIG. 2 shows the circuit configuration of the voltage detection unit 50 for performing this voltage measurement. A voltage dividing capacitor 8 is connected between the electrode 5 and the ground potential shields 2 and 1. Further, an optical PT or a power detection device 9 is connected in parallel to both ends of the voltage dividing capacitor 8. The output of the optical PT or the power detection device 9 is guided to the outside by an appropriate means. It should be noted that since known ones can be used for the optical PT and the power detection device 9, detailed description thereof will be omitted here.

Since the stray capacitance 7 exists between the conductor 4 and the electrode 5 which face each other, the voltage between the conductor 4 and the ground potential is divided by the stray capacitance 7 and the voltage dividing capacitor 8. . Therefore, the voltage across the conductor 4 can be measured by measuring the voltage across the voltage dividing capacitor 8 with the optical PT and the power detection device 9. Details of the structure for holding the electrode 5 are shown in FIG. In FIG. 3, (a) is a cross-sectional view showing the attachment structure of the electrode 5 to the shield 2, and (b) is a plan view and a side view of the insulating spacer used in (a).

A flange 31 bent in the opposite direction of the conductor 4 is formed in the cutout portion of the shield 2.
Further, a similarly bent flange 32 is formed around the electrode 5. The two flanges 31, 32 are FR
It is fixed by a bolt 36 via an insulating spacer 33 made of P. A counterbore hole 34 formed from the shield 2 side and a counterbore hole 35 formed from the electrode 5 side are formed in the insulating spacer 33. The electrode 5 and the insulating spacer 33 utilize the counterbore holes 34 and 35 to make a hexagon socket head cap bolt 36.
It is attached to the shield 2 with the nut 37.

FIG. 4 shows a single-line connection diagram of the GIS which employs the voltage detecting section having the above-mentioned configuration. In the figure, 21 is a busbar container that houses the busbar 10 and the disconnector 11, and 22 is a gas circuit breaker 12, a grounding switch 15, a current transformer 14, and a voltage detector 5.
0 is a circuit breaker container, 23 is a cable head 20
A cable head container for accommodating the disconnector 13, the grounding switch 16, and the voltage transformer 18, and a lightning arrester container 24 for accommodating the arrester 17.

Since the voltage detecting section 50 of this embodiment is housed in the current transformer 14 that has existed in the past, it is shown in FIG. 4 even in a place where there is no room for newly arranging a device like the breaker container 22. Thus, it can be easily provided. (Embodiment 2) FIG. 5 shows a modification of the electrode. The electrode 51 of this example is formed over the entire circumference of the conductor 4. Therefore,
The shield 2 is cut out over the entire circumference. Since the other points are the same as those of the first embodiment described above, duplicated description will be omitted. According to this example, the stray capacitance 7 between the conductor 4 and the electrode 51 can be increased.

(Embodiment 3) FIG. 6 shows an example in which the conductor 4 and the current transformer 14 are arranged in three phases. When arranged in three phases, the electrode 5 is affected by the electric fields from other phases. In order to eliminate this influence, first, as shown in the figure, a shield plate 6 of ground potential is arranged between the phases. With this shield plate 6, the conductors 4 of the other phase cannot be seen from each electrode 5,
The influence of the electric field of the other phase can be surely eliminated. When the shield plate 6 is provided, the electrode 51 formed over the entire circumference shown in FIG. 5 can be used.

Secondly, in the case of using the partial electrodes 5 as shown in the drawing, the electrodes 5 are arranged so that they are hidden by the shields 1 and 2 when viewed from the other phases. The influence of the electric field can be eliminated. In this case, the shield 6 can be omitted. (Fourth Embodiment) In the first to third embodiments described above, the shield 2 of the current transformer 14 is notched, and the electrodes 5 and 51 are provided in the cutout. Alternatively, an electrode for voltage detection may be separately formed and attached to the end of the current transformer 14. An example will be described with reference to the drawings.

FIG. 7 is a side sectional view of the current transformer 14 to which the voltage detecting section 52 is attached, and FIG. 8 is a side sectional view showing the details of the voltage detecting section 52. The voltage detector 52 is formed in a donut shape as a whole. Also, as described below,
The outside is covered with a shield case. The voltage detector 52 is attached integrally with the current transformer body 3 by a bolt 46. The current transformer body 3 is covered by the shields 1 and 2 as in the above-described embodiments. The shield 41 of the voltage detector 52 and the shields 1 and 2 of the current transformer 14 are shaped so as to form an overall shield when both are assembled.

As shown in FIG. 8, the voltage detector 52 includes an electrode 53 formed in an annular shape facing the conductor 4, and an electrode 52.
And a shield case 41 for holding. The attachment structure of the electrode 53 and the shield case 41 may be the same as that shown in FIG. Further, the impedance element 42 is housed in the shield case 41, and the electrode 53 and the ground are connected by the impedance element 42. A current transformer 45 for detecting the current flowing through the impedance 42 is provided. Reference numeral 43 is a bushing for pulling out the lead wire 44.

In this example, the voltage of the conductor 4 is detected by detecting the leakage current due to the stray capacitance 7. Current transformer 45
Detects the leakage current flowing through the impedance 42 by the stray capacitance 7. Thereby, the conductor 4 can be detected. It is also possible to use a transformer instead of the impedance element 42 and detect the leakage current from the secondary side of the transformer.

According to this embodiment, the voltage detector 52 can be easily removed when it is not necessary to detect the voltage. (Other Embodiments) The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

For example, in an example in which an electrode is provided in a notch formed in a shield as shown in FIGS. 1 to 6, as shown in FIG. 8, it is necessary to detect electric current by detecting a leak current. You can Further, in the case where the voltage detection unit is separately configured as shown in FIG. 7, the voltage can be measured by connecting the voltage dividing capacitor 8 as shown in FIG.

[0023]

EFFECTS OF THE INVENTION According to the present invention, a GIS capable of easily performing voltage measurement or voltage detection in a GIS container.
Can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a circuit configuration of FIG.

FIG. 3 is a view showing a mounting structure of electrodes in FIG.

FIG. 4 is a single-line connection diagram of GIS using the apparatus of FIG.

FIG. 5 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a third embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 8 is a diagram showing the structure of the voltage detection unit of FIG.

FIG. 9 is a single line connection diagram of a conventional GIS.

[Explanation of symbols]

 1, 2, 6 ... Shield 3 ... Current transformer 4 ... Conductor 5, 51, 53 ... Electrode 7 ... Stray capacitance 8 ... Voltage dividing capacitor 12 ... Circuit breaker 14, 45 ... Current transformer 22 ... Circuit breaker container 33 ... Insulation Spacer 42 ... Impedance element 50, 52 ... Voltage detection unit

Claims (2)

[Claims] 1. A gas-insulated switchgear having a wire wound current transformer arranged around a conductor and having a shield provided between the conductor and the conductor, and a cutout formed in a part of the shield facing the conductor. A gas-insulated switchgear comprising: an electrode provided in the cutout portion so as to face the conductor; and a means connected between the electrode and ground for detecting the voltage of the conductor. 2. A gas-insulated switchgear having a wire wound current transformer arranged around a conductor and having a shield provided between the conductor and the conductor. A gas-insulated switchgear comprising: an annular electrode; and means for detecting the voltage of the conductor, which is connected between the electrode and the ground.