JPH0886828A - Partial discharge detector for high voltage equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To detect a partial discharge with a simple structure, which can be applied to high-voltage equipment of any structure and has high sensitivity. [Structure] First grounding container 12 formed of a conductive member
a and the second grounding container 12b are insulating members 13a and 13b.
A high-voltage conductor 11 is arranged in a connection grounding container 12 formed by connecting via a wire, and a partial discharge generated inside the connection grounding container 12 is detected. , 12b is connected to the resistor 16, and the voltage value across the resistor 16 is measured by the measuring device 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial discharge detection device for a high voltage equipment suitable for monitoring a partial discharge generated inside a high voltage equipment such as a closed switchgear during actual operation.

[0002]

2. Description of the Related Art In a high voltage device such as a closed switchgear, when a partial discharge occurs inside the device during an actual system operation, this may cause a dielectric breakdown accident. Once such an accident occurs, it will result in extremely serious effects such as shaking and shutdown of the power system. Therefore, during actual system operation, internal partial discharges are detected to prevent equipment breakdown accidents.

In the high voltage equipment during actual operation, there are mainly three conventional methods for detecting the partial discharge generated inside, that is, an electrical method, an acoustic method and a vibration method. Of these, the electrical method will be described by taking a closed switchgear as an example. When partial discharge occurs inside the closed switchgear, a current pulse generated in an electric circuit is generated by a spacer made of epoxy resin for high voltage. There is a method of detecting with an electrode embedded inside.

This method will be described below with reference to FIG.
FIG. 3 is an internal cross-sectional view showing a part of the closed switchgear.
As shown in FIG. 3, the high-voltage conductor 1 is supported by a spacer 2 made of a high-voltage epoxy resin and is supported by a metal grounding container 3.
It is located inside. The ground container 3 is supported on the ground by a frame 4. A metal ring 5 is embedded in the spacer 2 so as to surround the high voltage conductor 1. The detection resistor 6 is also embedded in the spacer 2, one end of which is connected to the metal ring 5 and the other end of which is connected to the ground container 3 by the conductor 7. The connection between the metal ring 5 and the resistor 6 is connected to the measurement coaxial cable 8 connected to the measurement system. Furthermore, the jacket of the coaxial cable 8 is connected to the ground container 3 by a ground wire 9.

In FIG. 3, if a partial discharge occurs inside the closed switchgear for some reason, the discharge pulse current flows through the high voltage conductor 1 and the inner surface of the grounded container 3. At this time, the resistor 6 has a capacitance between the high-voltage conductor 1 and the metal ring 5, and the metal ring 5 and the ground container 3
A voltage that depends on the capacitance between them is generated, and discharge is confirmed by detecting this voltage. This voltage is usually less than a few millivolts.

[0006]

In the above method, since the metal ring 5 as an electrode exists inside the grounding container 3,
Other than the inside of the grounding container 3, for example, it is less likely to be affected by an unnecessary signal from the outside such as a partial discharge generated in an overhead power transmission line connected to a closed switchgear or the like through a bushing or a broadcast wave of a radio or a television. Further, as a matter of course, it is possible to measure the partial discharge generated inside the closed switchgear with high sensitivity.

However, the detection device shown in FIG. 3 can be applied only to a device having a disk-shaped spacer 2 surrounding the high-voltage conductor 1 and cannot be used for a device using a spacer other than the disk-shaped. There is a problem.

The present invention has been made in view of the above-mentioned circumstances, and is applicable to a high-voltage device of any structure with a simple structure, and a high-voltage device capable of detecting a highly sensitive partial discharge. An object is to provide a partial discharge detection device.

[0009]

In order to solve the above-mentioned problems, a partial discharge detection device for a high-voltage equipment according to the present invention has a first ground container and a second ground which are formed of a conductive member. In a partial discharge detection device of a high voltage device for arranging a high-voltage conductor in a connection grounding container formed to be connected to a container via an insulating member, and detecting a partial discharge generated inside the connection grounding container, A resistor is connected between the first and second grounded containers, and the voltage value across the resistor is measured by a measuring device.

[0010]

In the present invention having the above-mentioned structure, when partial discharge occurs inside the connecting grounded container, the discharge pulse current flows through the inner surfaces of the high voltage conductor and the connected grounding container.
Part of this discharge pulse current flows through the first grounding container connected to the second grounding container via the resistor, and causes a voltage drop in the resistor. Therefore, by measuring this voltage value with a measuring device, it is possible to detect the occurrence of partial discharge in the connected grounded container.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a partial discharge detection device for high voltage equipment according to the present invention. In FIG. 1, the high-voltage conductor 11 is supported by a spacer (not shown) and is arranged in a connection grounding container 12 made of a metal and made of a conductive member. The connection grounding container 12 is not grounded.
Ground container 12a and second ground container 12b grounded
It consists of and. That is, this second grounded container 1
The frame 2b is supported on the ground by a frame 14. Further, the first grounding container 12a and the second grounding container 12b are connected and formed via insulating members 13a and 13b.

Further, the circumference of the first grounding container 12a is
It is covered with a shield 20 member that is electrically connected to the second ground container 12b, and a resistor 16 is connected between the shield member 20 and the first ground container 12a. The outer peripheral surface of the first grounding container 12a is electrically connected to the coaxial cable 18 through the insulating terminal 21, and the ground side of the coaxial cable 18 is connected to the shield member 20 through the grounding wire 19 while being used as a measuring device. Is connected to the partial discharge measuring instrument 22. FIG. 2 is an equivalent electric circuit diagram of the partial discharge detection device for a high voltage device according to the present embodiment configured as described above.

Next, the operation of this embodiment will be described.
Now, if a partial discharge occurs in the connected grounded container 12 for some reason, the discharge pulse current flows through the high voltage conductor 11 and the inner surface of the connected grounded container 12. This time,
The resistor 16 includes a high voltage conductor 11 and a first grounding container 12a.
A voltage determined by the value of the capacitance between them is generated, and the occurrence of partial discharge is confirmed by detecting this voltage.

That is, when a partial discharge occurs inside the connected grounded container 12, the discharge pulse current is generated by the high voltage conductor 1.
1 and the connecting ground container 12 flow on the inner surface. A part of this discharge pulse current is passed through the resistor 16 to the first grounded container 1
2a, causing a voltage drop in the resistor 16. Therefore, by measuring this voltage through the coaxial cable 18 with the partial discharge measuring instrument 22,
It is possible to detect that a partial discharge has occurred.

In the equivalent circuit diagram shown in FIG. 2, the capacitance C _S is the capacitance between the high voltage conductor 11 and the first grounding container 12a, and the resistor 16 is connected in series to the capacitance C _S. Therefore, the current i _cs determined by the capacitance C _S flows through the resistor 16.

In general, the capacitance C _S is as large as about 10 pF to about 100 pF as compared with the conventional metal ring, and the current flowing through the resistor 16 is also large. Therefore, it is possible to perform highly sensitive measurement as compared with the conventional method.

Since the resistor 16 is covered by the shield member 20 in the above embodiment, if the coaxial cable 18 is shielded so that external noise does not enter, the partial discharge is not affected by the external noise. It enables highly sensitive measurement of.

[0018]

As described above, according to the partial discharge detection device for a high voltage device according to the present invention, the first grounding container and the second grounding container formed of the conductive member are insulating members. In the partial discharge detection device of a high-voltage device, wherein a high-voltage conductor is arranged in a connection grounding container formed by connecting via a connector, and a partial discharge generated in the connection grounding container is detected. Since a resistor is connected between the grounding containers of and the voltage value at both ends of this resistor is measured by a measuring device, it can be applied to high-voltage equipment of any configuration with a simple configuration and has high sensitivity. It is possible to provide a partial discharge detection device for high voltage equipment.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a partial discharge detection device for a high voltage device according to the present invention.

FIG. 2 is an electrical equivalent circuit diagram of FIG.

FIG. 3 is an internal cross-sectional view showing a part of a conventional closed switchgear.

[Explanation of symbols]

 11 high-voltage conductor 12 connection grounding container 12a first grounding container 12b second grounding container 13a, 13b insulating member 14 frame 16 resistor 18 coaxial cable 19 grounding wire 20 shield member 21 insulating terminal 22 partial discharge measuring instrument (measuring device) )

Claims (1)

[Claims] 1. A high-voltage conductor is arranged in a connection ground container in which a first ground container and a second ground container formed of a conductive member are connected and formed via an insulating member, and the connection is also provided. In a partial discharge detection device of a high voltage device for detecting a partial discharge generated inside a grounded container, a resistor is connected between the first and second grounded containers, and a voltage value across the resistor is measured. Partial discharge detection device for high-voltage equipment, characterized in that it is configured to measure.