JPH01122320A - Flashover detector for fault point orientation device - Google Patents

Abstract

PURPOSE:To prevent malfunction due to the invasion of electric noise, by a method wherein decision whether phosphorescence and flashover light have existed simultaneously or not is decided when the flashover light has disappeared. CONSTITUTION:Flashover light 1C, generated in a sealed vessel 1, is introduced into a light branching device 4 through a fiber cable 3 to branch it into two lights. One of the lights is inputted into a flashover light detecting means to output the electric signal of a predetermined waveform while the other light is inputted into a phosphorescence generating means 30 to generate phosphorescence and the phosphorescence is converted into another electric signal by a phosphorescence detecting means 50 to output a predetermined waveform. The output signal is continued for several seconds after the flashover light has disappeared. The output signals of the flashover light detecting means 40 and the phosphorescence detecting means 50 are inputted into a decision device 14 to compare these two input signals and output an electric signal when both of the signals are not zero whereby the existence of the flashover light 1C is indicated. According to this method, the malfunction of an electronic circuit due to electric noise, which caused the emission of the flashover light, will never caused and mistaken decision will never be effected.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is directed to the prevention of flash light caused by a flash fault in electrical equipment housed in a sealed container, such as gas-insulated equipment such as GIS used in power systems. This invention relates to flashlight detection in a device that detects a fault location by detecting.

[Conventional technology]

Electrical equipment stored in a sealed container, such as SF.

Conventionally, as a means for detecting a flash fault from a high voltage section to a ground potential section inside a gas-insulated device such as a GIS filled with gas, a window for transmitting light is provided in the sealed container, and the light passes through the window. A method is used in which flashlight is detected via a light receiving section.

Fig. 5 shows a conceptual diagram of the configuration of an example of a conventional accident point locating device using flashlight detection. When a flash of light tC is emitted, it is received at the tip of a fiber cable 3 installed outside a window 2 which is a hole in the sealed container 1, and this flash of light passes through the fiber cable 3 to a photoelectric converter. 5, the electric signal is amplified by an amplifier 6, shaped into a predetermined waveform by a waveform shaper 7, and displayed on a display 15 to indicate that a flashover has occurred.

Various proposals regarding these light receiving means and flash light detection means have already been made, and are disclosed in Japanese Patent Application Laid-open Nos. 56-15133, 56-29423, 59-53018, and 59-53019. There are examples.

The photoelectric converter 5 in Fig. 5 usually uses a photodiode, but since the output current of this photodiode is weak, if some electrical noise is superimposed on this output current circuit, , this failure detection circuit may malfunction.

Possible sources of this noise include noise caused by sudden voltage or current fluctuations when circuit breakers open and close, short-circuit currents that occur during short-circuit accidents in power transmission systems or substations, or lightning strikes. It is conceivable that noise may enter from a commercial frequency AC lead introduced from the outside to supply power to an electronic device, or may propagate through space as electromagnetic waves and enter the output circuit of the photodiode. In consideration of the presence of such noise, noise-cutting transformers are used for AC power supplies, and electronic circuits are housed in iron cases to prevent intrusion of electromagnetic waves. Countermeasures are taken, such as creating a structure that acts as an electromagnetic shield, but it is not possible to detect all noise sources and take countermeasures in advance, and even if unexpected noise enters, it cannot be detected. It is necessary to have a fail-safe configuration to prevent the equipment from malfunctioning.

[Problem that the invention seeks to solve]

As mentioned above, sufficient noise countermeasures are required for electronic equipment installed in substations, but there are limits to measures to eliminate noise, and it is better to develop a method that does not malfunction even if noise enters. A detection circuit that employs this method is desirable.

An object of the present invention is to provide a failure point locating device for gas insulated equipment that does not malfunction even if electrical noise intrudes.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, flash light generated inside a sealed container is received outside the sealed container by a light receiving means, and the received flash light is converted into an electrical signal by an electrical conversion means. phosphorescence generating means for irradiating a phosphorescent substance with the flashlight received by the light receiving means to excite the phosphorescent substance and generate phosphorescence; , a phosphorescence detection means that receives phosphorescence generated by the phosphorescence generation means and converts it into an electrical signal, and both an output signal of the flashlight detection means and an output signal of the phosphorescence detection means are detected. and a determination means that sometimes emits an electric signal.

[Function] In the configuration of the present invention, in addition to the flash detection circuit that receives flash light generated in the sealed container by the flash light receiving means and converts the received flash light into an electrical signal, When flashlight is introduced into the phosphorescence generating means to generate phosphorescence, this phosphorescence continues to emit light even after the flashlight disappears, so this phosphorescence is converted into an electrical signal by the phosphorescence detection means. Once converted, this electrical signal can be detected as an electrical signal that continues even after the flash light has disappeared. Therefore, even if the electronic circuit malfunctions in detecting flash due to noise caused by the short circuit current that causes the flash, it is possible to reliably detect the occurrence of a flash fault. The decay time constant of phosphorescence can be selected to be several seconds, and by providing the phosphorescence detection means with a low-pass filter that cuts off frequencies of several Hz or more, the phosphorescence detection means can be used while reliably excluding high-frequency noise components. Since the output signal of the phosphorescence detection means can be made to remain almost unchanged, the phosphorescence detection means can be made into a circuit that is free from malfunction due to high-frequency electrical noise. Furthermore, by providing a determination means that determines that a flash fault has occurred only when both the output signal of the flash light detection means and the output signal of the phosphor light detection means are generated, it is possible to prevent phosphorescence caused by leakage light from the outside. Even if the photodetection means malfunctions, the flashlight detection means does not emit an electrical signal, so the determination means does not determine that a flashover failure has occurred, so this is a countermeasure against malfunction of the phosphorescence detection means.

〔Example〕

The present invention will be explained below based on examples. FIG. 1 is a conceptual diagram showing an embodiment of the present invention, where l is a sealed container, IA is a high voltage lead, IB is an arc generated when a flash occurs from the high voltage lead IA to the sealed container l, and IC is an arc generated by this arc. 20 is a light receiving means consisting of a window 2 and a fiber cable 3; 40 is a flash detecting means consisting of a photoelectric converter 5, an amplifier 6, and a waveform shaper 7; is also the same as Figure 5. 4 is a light branching device; 30 is a phosphorescence generating means, for example, consisting of a phosphorescent substance 9 such as a coronene solution with a decay time constant of 9.4 seconds; 50 is a phosphorescence detection means; a photoelectric converter 10; It consists of an amplifier 11, a low-pass filter 12, and a waveform shaper 13, and 14 is a determiner as a determining means.

When the high voltage lead IA in the sealed container 1 flashes for some reason and generates an arc IB toward the sealed container 1, the flash light 1C generated from the arc IB also has a component that reflects off the inner wall of the sealed container 1. Including leaks to the outside from window 2. The fiber cable 3 captures the flashlight IC leaking from the window 2.
The light is introduced into the optical splitter 4, where the light is split into two lights, and one of the lights is input to the flashlight detection means 40, as in the conventional case, and outputs an electrical signal with a predetermined waveform. On the other hand, the other light branched from the optical splitter 4 is input to the phosphorescence generating means and generates phosphorescence, but this phosphorescence continues with the time constant peculiar to the phosphorescent substance 9 even after the phosphorescent light disappears. Continues to generate phosphorescence while attenuating. This phosphorescence is converted into an electrical signal by the phosphorescence detection means 50 and output in a predetermined waveform, but the output signal of this phosphorescence detection signal is a signal that continues for several seconds even after the flashlight has disappeared. ing. The output signal of the flashlight detection means and the output signal of the phosphorescence detection means are determined by a determiner 1.
4, and the determiner 14 compares these two input signals and, when both signals are not zero, expresses the presence of flashlight by emitting an electric signal.

To explain the above operation including changes in the waveform of each part,
The waveform of the output signal of the opto-electrical converter 5 that receives the flashlight IC as input is a waveform that is half-wave rectified alternating current, as shown in waveform 101 in FIG. This is because the waveform is proportional. This waveform 101 is
The pulse is amplified by the waveform shaper 7 and shaped into a rectangular pulse as shown in the waveform 102. Although this is not shown, the waveform 101 is passed through a low-pass filter that cuts frequencies above 50 to 60 Hz, which is the system frequency, and the output signal is zero for human power below a certain value and exceeds this value. A human input signal can be obtained by passing it through a comparator that outputs a constant electric signal.

On the other hand, the output signal of the opto-electrical converter 10 and the output signal of the amplifier 11 using the phosphorescent light emitted from the phosphorescent material 9 irradiated with flash light have a waveform like the waveform 201.
During the period from time t1 to t2, which is the period in which flashlight exists, the reflected light from the flashlight reflected on the surface of the phosphorescent material also becomes the output signal of the photoelectric converter 10, so that the waveform 201 is shown. Between time L1 and L2, waveforms corresponding to flashlight are superimposed. Since it is not necessary to accurately convert this flashlight component into an electrical signal, the opto-electrical converter IO and amplifier 11 are designed to be saturated with respect to this flashlight component, so the waveform 201 is shown. The flashlight component has a wavefront portion cut off. This waveform 203 is filtered by a low-pass filter 12.
When input to , the output signal will look like waveform 203,
All harmonic components contained in the flashlight component are cut out in the waveform. By inputting this waveform 203 to the comparator 13, a waveform 204 is obtained as an output signal, and this waveform 204 becomes a rectangular pulse that continues for several seconds from t near time L1 until time t4.

FIG. 3 is a block diagram showing details of the determiner 14.
．． 142 is a circuit that detects the wave tail of an input signal using a one-shot multi-pipe rake and generates a rectangular pulse of a constant width, and 143 is an AND circuit that outputs an output signal when two input signals are not zero at the same time. It is a circuit. FIG. 4 is a time chart showing the waveform of the electric signal at each position in the circuit in the judger 14. One shot multi-bye break 1
41 outputs a waveform 301 with a width of t5-L2, and this electric signal becomes a human signal for the one-shot multivibrator 142, and this one-shot multivibrator 1
42 outputs a waveform 302 with a width of -L. The two waveforms, this waveform 302 and the waveform 204 which is the output signal of the phosphorescence detection means, become the input signals of the AND circuit 143, and the time L4 of the wave tail of the waveform 204 is the time t of the wave tail of the waveform 302.
6, so the output signal of the AND circuit is the same as the waveform 302 at time t.

From 1. It becomes a rectangular pulse that continues for a period of time.

The one-shot multi-by-break 141 performs the calculation for the final judgment by the AND circuit 143.
Since this is a period delayed by a certain period from the period in which the flashlight exists, accurate calculations can be performed without the influence of noise caused by the short circuit current that is the cause of the flashlight.

Furthermore, if a malfunction occurs in the phosphorescent light detection means 40 for some reason and the output signal 102 is generated even though no flash light is generated, the output signal of the phosphorescence detection means remains zero, so the determiner 14 also produces no output signal. Furthermore, even if a malfunction occurs before the phosphorescence detection means and the phosphorescence detection circuit emits an electrical signal even though no flashlight is generated, the output signal of the flashlight detection means is zero, so in this case as well, the determiner 14 does not emit an output signal.

In this way, even if any of the detection means malfunctions and generates an output signal, the decision is made by the decision device that makes the final decision.

〔Effect of the invention〕

As described above, this invention divides the flash light into two parts using an optical splitter, one of which is input to the conventional flash light detection means, and the other flash light is input to the conventional flash light detection means. The generation means manually generates phosphorescence, and the determination means determines whether or not the phosphorescence and flashlight exist at the same time when the flashlight disappears. The configuration is such that the electronic circuits serving as the means described above will not malfunction due to electrical noise caused by short-circuit current generated by short-circuiting of the high-voltage leads. As a result, when a flash fault occurs in a sealed container such as gas-insulated equipment, the position within the sealed container where the flash fault occurred is incorrectly determined by detecting the flash light due to a malfunction of the electronic circuit. This makes it possible to create a highly reliable detection method that is free from the fear of

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing an embodiment of this invention, and Figure 2 is a conceptual diagram showing an embodiment of the invention.
FIG. 3 is a block diagram of the determiner, FIG. 4 is a time chart for explaining the operation of the determiner, and FIG. 5 is a conceptual diagram of an example of the prior art. 1... Sealed container, IA... High pressure lead, 1B...
Arc, IC...flash light, 2...window, 20...light receiving means, 3 fiber cable, 30...phosphorescence generating means, 4...optical splitter, 40...flash light Photodetection means, 5.10... Photoelectric conversion means, 6.11... Amplifier, 7... Waveform shaper, 50... Phosphorescence detection means, 1
2...Low pass filter, 9...phosphorescent substance, 9
1... Phosphorescence, 13 Comparator, 14... Determiner, 141.142... One-shot multi-by-break, 143... AND circuit, 101.102, 201, 202, 203° 204.3
01, 302, 303... Waveform. 1Az Sendai 3?2I Daitomon

Claims (1)

[Claims] 1) A failure point locating device equipped with a flashlight detection means for receiving flashlight generated inside the sealed container outside the sealed container by a light receiving means and converting the received flashlight into an electrical signal by an electrical conversion means. , a phosphorescence generating means for irradiating a phosphorescent substance with the flash of light received by the light receiving means to excite the phosphorescent substance to generate phosphorescence; and a phosphorescence generating means for receiving the phosphorescence generated by the phosphorescence generating means. phosphorescence detection means for converting the phosphorescence into an electric signal; and determination means for emitting an electric signal when both the output signal of the flashlight detection means and the output signal of the phosphorescence detection means are detected. A flash fault detector for a failure point locating device.