JP3102129B2 - Internal arc detector for gas insulation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated device in which an electric device is sealed together with an insulating gas in a sealed container.
The present invention relates to an internal arc detection device that detects an arc light due to the generation of an internal arc when a ground fault or the like occurs inside the sealed container, and detects an abnormality of the gas insulation device.

[0002]

2. Description of the Related Art A conventional internal arc detecting device will be described with reference to FIG. In the figure, 1 is a tank of a gas insulation device,
Reference numeral 2 denotes a conductor housed in the tank 1 together with the insulating gas, and reference numeral 9 denotes an arc light generated by an internal arc such as a ground fault. Reference numeral 3 denotes a sensor unit, which is attached to the tank 1 and whose tip faces the inside of the tank 1. When the arc light 9 is generated, the arc light 9 enters the sensor unit 3. The arc light 9 incident on the sensor unit 3 is sent to the O / E converter 5 by the optical fiber 4 as an optical signal.

[0003] An O / E converter 5 converts an optical signal into an electric signal. The converted electric signal is amplified by the amplifier 6 and output to the comparator 7. The comparator 7 compares the amplified signal with the noise level, and when detecting a signal having a certain value or more, issues a warning of the occurrence of an internal arc in the tank 1.

In such an internal arc detecting device, it is extremely rare that arc light is generated inside the tank 1 due to a ground fault or the like. Therefore, a self-inspection function is required for the device itself to check whether the device can reliably detect arc light for a long time.

As an example of a self-checking function, a check pulse generator 8 is provided. The inspection pulse generator 8 generates a pulse signal at the time of self-inspection, and inputs the pulse signal to a stage preceding the amplifier 6 and the comparator 7. The comparator 7 detects an abnormality of the apparatus by comparing the output of the amplifier 6 with the output of the check pulse generator 8.

[0006]

In the above conventional apparatus, there is a problem that the detection signal of the comparator 7 is invalidated during the self-inspection, so that the arc light cannot be detected during the self-inspection. The target of self-check is O / E
Since only the portion after the converter 5 is provided, it is difficult to cut the optical fiber 4 and detect a failure of the O / E converter 5.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an internal arc detecting device of a gas insulated device which can detect arc light even at the time of self-inspection and can detect a failure of the entire device. Things.

[0008]

According to the present invention, in order to achieve the above object, a pulse-like inspection signal is converted into an optical signal in an internal arc detecting device of a gas-insulated equipment having a self-inspection function. A signal is introduced into a sensor unit for detecting arc light, and the occurrence of internal arc light and the presence of an abnormality in the device are detected using the signal obtained from the sensor unit and the inspection signal.

[0009]

According to the above-described means, since the inspection signal is converted into light and the inspection signal is introduced to the sensor section, it is possible to detect an abnormality in the apparatus with respect to all the subsequent sections from the sensor section. Also, by comparing the inspection signal with the signal in which the arc light detected by the sensor unit and the inspection signal are superimposed, it is possible to detect the arc light even when arc light is generated during the self-inspection. Become.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows an outline of the present embodiment. In the figure,
Reference numeral 1 denotes a tank of a gas insulating device, 2 denotes a conductor housed in the tank 1 together with an insulating gas, and 9 denotes an arc light generated at the time of a ground fault.

Reference numeral 3 denotes a sensor unit, which is attached to the tank 1 and whose tip faces the inside of the tank 1. A half mirror 10 is provided on the front surface of the sensor unit 3. When the arc light 9 is generated, the arc light 9 passes through the half mirror 10,
Enter the sensor unit 3. The arc light 9 condensed by the sensor unit 3 is sent to the O / E converter 5 by the optical fiber 4 as an optical signal.

The O / E converter 5 converts an optical signal into an electric signal. The converted electric signal is amplified by the amplifier 6 and output to the comparator 7. The comparator 7 compares the amplified signal with the noise level and detects light emission inside the tank 1. The operation of the comparator 7 will be described later in detail.

Inspection pulse generator 8 for performing self-inspection
Outputs a check signal of the pulse signal to the comparator 7 and the E / O converter 11. The E / O converter 11 converts the inspection signal into light to generate inspection light. The inspection light is optical fiber 1
2, the light is introduced into the half mirror 10 on the front surface of the sensor unit 3. The half mirror 10 reflects the inspection light only in the direction of the sensor unit 3, and the inspection light enters the sensor unit 3.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 shows waveforms for explaining the operation, and FIG. 3 is a block diagram showing details of the comparator 7.

FIG. 2A shows a waveform of the arc light 9 generated at the time of a ground fault. This waveform has the same frequency component as the commercial frequency applied to the conductor 2. FIG. 2B shows a waveform of the inspection light obtained by converting the pulse signal generated in the inspection pulse generator 8 by the E / O converter 11. FIG. 2C shows a waveform in which arc light and inspection light are superimposed when an internal arc occurs during self-inspection.

If there is no abnormality in the internal arc detecting device from the sensor section 3 to the comparator 7 shown in FIG.
The output of the converter 5 is as follows. If an internal arc occurs when the self-check is not performed, the waveform of FIG. 2A is obtained. When the self-check is performed when no internal arc is generated, the waveform shown in FIG. 2B is obtained. If an internal arc is generated during the self-check, the waveform shown in FIG. 2C is obtained.

The output of the O / E converter 5 is supplied to an amplifier 6
And digitized using a suitable threshold. FIG. 2D shows a waveform obtained by processing the waveform of FIG.

Here, the comparator 7 will be described with reference to FIG. Signals from the amplifier 6 and the inspection pulse generator 8 are input to the comparator 7. The comparator 7 includes an arc detection logic circuit 31 and a device abnormality detection logic circuit 32.

In the arc detection logic circuit 31, a signal from the amplifier 6 is input to one input terminal of the AND circuit 33, and a signal from the check pulse generator 8 is input to the inverter 3
4 is input to the other input terminal of the AND circuit 33. The output of the AND circuit is input to the arc light detection circuit 37.

In the device abnormality detection logic circuit 32, a signal from the amplifier 6 is input to one input terminal of the AND circuit 36, and a signal from the check pulse generator 8 is input to the other input terminal of the AND circuit 36. You. The output of the AND circuit 36 and the signal from the check pulse generator 8 are output from the EOR circuit 35.
Is input to The output of the EOR circuit 35 is input to the device abnormality detection circuit 38.

Next, the operation of the comparator 7 will be described. First, the operation of the arc detection logic circuit will be described.

(1) If no self-inspection is performed and no ground fault occurs, the sensor unit 3 does not detect light and the signal from the amplifier 6 is always 0, so that the gate is closed, and There is no output from the circuit 33 to the arc light detection circuit 37.

(2) If an internal arc occurs when the self-inspection is not performed, the output of the inspection pulse generator 8 is always 0 and the output inverted by the inverter 34 is always 1; Is open. Since the amplifier 6 outputs a signal corresponding to the arc light, the AND circuit 33 outputs an output to the arc light detection circuit 37. Thereby, the arc light detection circuit 37 issues an alarm for arc light detection.

(3) If self-inspection is performed and no internal arc is generated, the sensor unit 3 detects the inspection light shown in FIG. 2B, and the signal from the inspection pulse generator 8 is the same as the signal from the amplifier 6. Both the waveform and the phase are the same. Therefore,
The inputs are alternately input to the two input terminals of the AND circuit 33 and are not input simultaneously, so that no output is output to the arc light detection circuit 37. That is, the arc light detection circuit 37 is not operated by the inspection signal.

(4) When an internal arc occurs during self-check, the output waveform of the amplifier 6 to the AND circuit 33 is as shown in FIG.
As shown in FIG. 2D, the output waveform of the inspection pulse generator 8 is the same as the waveform shown in FIG. 2B. Since the output of the AND circuit 33 is output when both inputs are 1, the output is as shown in FIG. 2E. Therefore, this is the arc light detection circuit 3
7 to issue an alarm for arc light detection.

As described above, regardless of whether the self-inspection is performed or not, the detection of the arc light is reliably performed, and the malfunction of the arc light detection due to the self-inspection does not occur.

Next, the operation of the device abnormality detection logic circuit 32 will be described. The case where the self-inspection and the internal arc occur in the same manner has already been described in the above (2).

(5) Sensor part 3, optical fiber 4, O / E
If there is no abnormality in the entire internal arc detecting device including the converter 4 and the amplifier 6, both the output of the amplifier 6 and the output of the check pulse generator 8 become the same as the waveform of FIG. The same input is applied to the two input terminals, and the output of the AND circuit 36 has the same waveform. Therefore, EO
Since the same waveform is input to the two input terminals of the R circuit 35, the E / O converter 35 sends the device abnormality detection logic circuit 37
Is not output, and no alarm is issued for device abnormality.

(6) Contrary to the above (5), when there is an abnormality in a part of the internal arc detecting device, the output of the amplifier 6 disappears. As a result, the gate of the AND circuit 36 is closed and the output is always 0, so that the input of one input terminal of the EOR circuit 35 is also always 0. Therefore, every time a signal from the check pulse generator 8 is input to the other terminal of the E / O converter 35, the EOR circuit 35 outputs an output to the device abnormality detection logic circuit 37, and the device abnormality logic circuit 37 An alarm is issued for abnormality.

As described above, it is possible to detect an abnormality in the entire internal arc detecting device including the sensor section 3, the optical fiber 4, the O / E converter 4, and the amplifier 6.

Although the present invention has been described in detail with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist of the invention. Absent.

For example, the element for introducing both the arc light and the inspection light into the sensor section is not limited to a half mirror. Any structure can be adopted as long as the light from the optical fiber 12 can be introduced into the sensor unit without causing an obstacle in the detection of arc light in the sensor unit. Also,
The specific configuration of the means for realizing each function can be variously changed.

[0034]

According to the present invention, in an internal arc detecting device of a gas insulated device having a self-inspection function for detecting an abnormality of the device itself, an internal arc is generated due to a ground fault or the like during a self-inspection. Even if it occurs, the occurrence of an internal arc can be reliably detected and an alarm or the like can be performed. Therefore, the reliability of the internal arc detection device is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining an embodiment of the present invention.

FIG. 2 is a graph showing waveforms for explaining the operation of the embodiment of the present invention.

FIG. 3 is a block diagram of a comparator according to the present invention.

FIG. 4 is a schematic diagram for explaining a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tank, 2 ... Conductor, 3 ... Sensor part, 4,12 ... Optical fiber, 5 ... O / E converter, 6 ... Amplifier, 7 ... Comparator, 8 ... Check pulse generator, 9 ... Arc light, 10 ... Half mirror, 11 E / O converter, 31 Arc detection logic circuit, 32 Device abnormality detection logic circuit, 37 Arc light detection circuit, 38 Device abnormality detection circuit

Claims (1)

(57) [Claims] 1. A means for converting an inspection pulse signal for self-inspection into an optical signal in an internal arc detection device for a gas-insulated equipment for detecting an arc light of an internal arc of the gas-insulated equipment by a sensor unit, and the optical signal And a means for detecting the occurrence of internal arc light and the presence of an abnormality in the device by comparing a signal obtained from the sensor unit with the inspection pulse signal. Characteristic internal arc detection device.