JP3495602B2 - Method and apparatus for detecting abnormality of surge suppression element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting method and an abnormality detecting device for a surge suppressor, and more particularly to an insulating washer for a fastening body for fastening between opposed flanges of a metal container filled with high pressure gas in an insulating state. TECHNICAL FIELD The present invention relates to an abnormality detection method and an abnormality detection device for a surge suppression element that detects an abnormality such as deterioration or damage of a zinc oxide (ZnO) tubular element used for.

[0002]

2. Description of the Related Art Generally, in a gas-insulated switchgear,
Insulation sections are provided for each of the one or more metal containers so that circulating current does not flow in the metal container that is filled with high-pressure gas and grounded. When flange-joining a metal container of an insulating section disposed adjacently, an insulating spacer is interposed between the flanges to be joined, and a fastening body that fastens these flanges, that is, a stud bolt and one flange. An insulating washer is interposed between the flanges to insulate them.

Here, FIG. 7 is a block diagram showing a state of a joint portion of two metal containers adjacent to each other in a known gas-insulated switchgear, showing a part of the joint portion.

In FIG. 7, 21 is one metal container, 2
1F is a flange of the metal container 21, 22 is the other metal container adjacently arranged, 22F is a flange of the metal container 22, 2
3 is an insulating spacer, 24 is a stud bolt, 25 is a nut, 26 is a first insulating washer, and 27 is a second insulating washer.

Then, one metal container 21 has a flange 21F at one end, and the other metal container 22 also has a flange 22 at one end. The insulating spacer 23 is interposed between the flange 21F of the one metal container 21 and the flange 22F of the other metal container 22, and the stud bolt 24 and the nut 25 are used for fastening between the flange 21F and the flange 22F. Stud bolt 24 is flange 21
F is inserted through the insulating spacer 23 into the flange 22F, and the first insulating washer 26 or the second insulating washer 27 is interposed on the flange 21F side.
The nut 25 is fitted on the side.

FIG. 8 is a cross-sectional view showing a detailed structure of a portion fastened by using a first insulating washer 26 in the coupling portion shown in FIGS. 8 and 7.

In FIG. 7, 27 is zinc oxide (ZnO)
The tubular element, 28 is an insulating outer tubular body, 29 is an insulating layer, and the same components as those shown in FIG. 7 are designated by the same reference numerals.

The first insulating washer 26 comprises a tubular element 27 made of zinc oxide and an insulating outer tubular body 2 covering the outer periphery thereof.
It consists of 8. When the stud bolt 24 is tightened, the stud bolt 24 is inserted into the center opening (no drawing number) of the zinc oxide tubular body element 27 of the first insulating washer 26.
The first insulating washer 26 is interposed between the flange portion 21F and the umbrella portion (not shown) of the stud bolt 24 by tightening the nut 25 inserted into the other end of the stud bolt 24. At this time, the insulating layer 29 is arranged between the inner peripheral surface of the insertion hole of the stud bolt 24 in the flange 21F and the outer peripheral surface of the stud bolt 24 facing it, and the flange 21F and the stud bolt 24 in the insertion hole of the stud bolt 24 are arranged. The insulation between and is secured.

Although not shown in FIG. 8, the second insulating washer 27 is slightly different from the first insulating washer 26 in that the second insulating washer 27 is composed of only an insulating tubular element. However, when the stud bolt 24 is tightened, the stud bolt 2 is inserted into the center opening of the insulator tubular element.
4 is inserted, and the nut 25 fitted into the other end of the stud bolt 24 is tightened, and the second insulating washer 27 is interposed between the umbrella portion of the stud bolt 24 and the flange 21F.

In the gas-insulated switchgear having the above structure, the one metal container 21 and the other metal container 22 are insulated from each other by the insulating spacer 23 and the first and second insulating washers 26 and 27. Even if an induced current flows in either one or both of the one metal container 21 or the other metal container 22, the induced current may flow to the other metal container 22 or the one metal container 21 adjacent thereto. In addition, no induction current flows through the metal containers 21 and 22.

In the gas-insulated switchgear of this type, when the stud bolts 24 are fastened, all the insulating washers are the second insulating washers 27 made of an insulating tubular element. When a large and steep surge voltage is generated between the metal container 21 on one side and the metal container 22 on the other side when a current is disconnected, the surge voltage causes creeping dielectric breakdown of the insulating tubular element. It happened.

Therefore, like the known gas-insulated switchgear, when the stud bolt 24 is fastened, the second insulating washer 27 is used, and the first zinc oxide tubular body element 27 is incorporated. Insulation washers 26 have come to be used. Further, in the known gas-insulated switchgear, creeping dielectric breakdown does not occur in the zinc oxide tubular element 27 when the surge voltage as described above is induced,
Compared to the one in which the second insulating washer 27 is used for all the insulating washers, the one in which the first insulating washer 26 and the second insulating washer 27 are used together causes the insulation tubular element to cause the creeping dielectric breakdown. The rate of occurrence has been greatly reduced.

[0013]

In the known gas-insulated switchgear, even if a large steep surge voltage is induced between the one metal container 21 and the other metal container 22, the first
The tubular element 27 made of zinc oxide contained in the insulation washer 26 does not cause the surface dielectric breakdown, but after absorbing the surge voltage for a long period of time or after several large surge voltage impacts. After the voltage is applied, the tubular element 27 made of zinc oxide has an abnormality such as deterioration of insulation and damage in some cases. Then, when an abnormality occurs in the zinc oxide tubular body element 27, an induced current based on the large steep surge voltage induced in the abnormal zinc oxide tubular body element 27 causes another zinc oxide tubular body element. It flows more intensively than the element body 27,
The abnormal zinc oxide tubular element 27 is thermally damaged or the stud bolt 24 is thermally deformed.

By the way, the zinc oxide tubular element 27 contained in the first insulating washer 26 is normal in appearance even if an abnormality such as insulation deterioration occurs, except for mechanical damage. Cylindrical element 27 made of zinc oxide having insulating properties
It is difficult to clearly distinguish it from the first insulating washer 2
Even when the zinc oxide tubular body element 27 built in 6 is regularly inspected, the abnormal zinc oxide tubular body element 27 cannot be identified.

Until now, in addition to visually inspecting the zinc oxide tubular element 27 for abnormality, an effective detecting means for detecting an abnormality of the zinc oxide tubular element 27 has been available. , No suggestions have been made.

The present invention has been made in view of the above technical background, and an object thereof is to quickly detect an abnormality of a zinc oxide tubular body element incorporated in an insulating washer by a simple detecting means. An object of the present invention is to provide an abnormality detection method and an abnormality detection device for a surge suppression element, which enables accurate detection.

[0017]

In order to achieve the above-mentioned object, a method of detecting an abnormality of a surge suppressor according to the present invention is provided with one or a plurality of insulating washers each having a tubular element made of zinc oxide. Apply a stepwise or pulsed detection voltage between the opposing flanges of the metal container to obtain the time constant of the damping voltage at the specified resonance frequency obtained between the flanges, and compare the obtained time constant value with the reference time constant value. Alternatively, a stepped or pulsed detection voltage is applied between the opposing flanges of adjacent metal containers that have a plurality of insulating washers with built-in zinc oxide tubular elements, and the damped oscillation voltage is obtained between the flanges. The resonance frequency value is calculated and the calculated resonance frequency value is compared with the reference resonance frequency value to detect an abnormality of the zinc oxide tubular element, or the first means is provided.

According to the first means, the detection voltage is applied to both ends of the zinc oxide tubular element (the zinc oxide tubular element to be detected) in which the abnormality is detected, and the detection voltage is applied. Correspondingly, the time constant of the damping voltage of the predetermined resonance frequency or the resonance frequency of the damping vibration voltage obtained from the zinc oxide element to be detected is obtained, and the obtained time constant value or the resonance frequency value is set to the standard time, respectively. By comparing the numerical value or the standard resonance frequency value, it is possible to detect the abnormality of the zinc oxide tubular element to be detected. It becomes possible to detect an abnormality accurately at an early stage.

In order to achieve the above-mentioned object, the surge suppressor abnormality detection apparatus according to the present invention provides a detection voltage generating section for generating a step-shaped or pulse-shaped detection voltage and one output of the detection voltage generating section. A first detection voltage supply terminal connected via an impedance connected in series, a second detection voltage supply terminal directly connected to the other output of the detection voltage generator, a first measurement terminal and a second measurement terminal, One and the other inputs are connected to the first and second measurement terminals, respectively,
A time constant measuring device for measuring the time constant of the decay voltage of a predetermined resonance frequency, and a state judging device for comparing the measured time constant value with a reference time constant value, or a detection voltage generating part and a detection voltage generating part. A first detection voltage supply terminal connected to one output via a series-connected impedance, a second detection voltage supply terminal directly connected to the other output of the detection voltage generation unit, a first measurement terminal and a first measurement terminal 2 measuring terminals, first and second
One means and the other input are respectively connected to the measurement terminals, the second means comprising a frequency measuring device for measuring the resonance frequency of the damped oscillation voltage and a state judging device for comparing the measured resonance frequency value with the reference resonance frequency value. To have.

According to the second means, a device for detecting an abnormality of a zinc oxide tubular element (a zinc oxide tubular element to be detected) in which an abnormality is detected is connected in series with a detection voltage generating section. In addition to impedance, we are only using each device of time constant measuring device and state judging device, or each device of frequency measuring device and state judging device. The abnormality of the zinc oxide tubular element to be detected can be detected by a relatively simple device, and the abnormality can be detected accurately at an early stage.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In one of the first embodiments of the present invention, a method of detecting an abnormality of a surge suppression element is an electrically insulating state between opposing flanges of a metal container in which high pressure gas is sealed. It is used for an insulating washer of a fastening body to be fastened and detects an abnormality of one or a plurality of zinc oxide tubular body elements whose outer periphery is covered with an insulating tubular body, and has a step-like or pulse-like shape between flanges. Voltage is applied, the time constant of the damping voltage at the specified resonance frequency obtained between the flanges is calculated, and the calculated time constant value is compared with the reference time constant value to check for abnormalities in the tubular element made of zinc oxide. It is something to detect.

In a specific example of one of the first embodiment of the present invention, the abnormality detection method of the surge suppressor is performed by using a zinc oxide tubular body element in a good insulating state to detect the abnormality. The time constant value obtained at that time is used as the reference time constant value.

In another embodiment of the first embodiment of the present invention, a method of detecting an abnormality of a surge suppressor is a method in which a plurality of flanges of a metal container in which high pressure gas is sealed are fastened in an electrically insulated state. It is used for each insulating washer of the fastening body of the above, and detects abnormalities of a plurality of tubular elements made of zinc oxide whose outer circumference is covered with an insulating tubular body. Step-shaped or pulse-shaped detection between flanges A voltage is applied, the resonance frequency of the damping vibration voltage obtained between the flanges is obtained, and the obtained resonance frequency value is compared with the reference resonance frequency value to detect abnormalities in multiple zinc oxide tubular elements. Is.

In one preferred embodiment of the first embodiment of the present invention and another preferred embodiment thereof, the method of detecting an abnormality of a surge suppressing element is to apply a detection voltage between flanges via an impedance.

According to the first embodiment of the present invention, when the abnormality of the zinc oxide tubular element (the zinc oxide tubular element to be detected) is detected, the zinc oxide to be detected is detected. When a stepped or pulsed detection voltage is applied to both ends of the tubular element, and in response to the application of the detection voltage, there is an attenuation voltage of a predetermined resonance frequency output from the zinc oxide tubular element to be detected. Calculate the constant value or the resonance frequency of the damping vibration voltage output from multiple zinc oxide tubular elements to be detected, and set the obtained time constant value or resonance frequency value to the preset standard time. Since it compares with a constant value or standard resonance frequency value and detects the abnormality of the zinc oxide tubular element to be detected based on the comparison result,
An abnormality of the zinc oxide tubular body element to be detected can be detected early and accurately by using a simple detecting means without exposing the zinc oxide tubular body element to be detected.

In one of the second embodiment of the present invention, the surge suppression element abnormality detecting device is a fastening body for electrically fastening between opposed flanges of a metal container filled with high pressure gas. Which is used for the insulation washer of the present invention and which detects an abnormality of a zinc oxide tubular element whose outer periphery is covered with an insulating tubular body, and which has a detection voltage generating section for generating a stepped or pulsed detection voltage, and A first detection voltage supply terminal connected to one output of the step detection voltage generation section via an impedance connected in series, and a second detection voltage supply terminal directly connected to the other output of the step detection voltage generation section , A first measuring terminal and a second measuring terminal, a time constant measuring device having one and the other inputs respectively connected to the first and second measuring terminals and measuring a time constant of an attenuation voltage at a predetermined resonance frequency, and a time constant. A state determiner that compares the time constant value measured with a standard time constant value with a reference time constant value, and at the time of detection, connect the first detection voltage supply terminal and the first measurement terminal to one of the flanges, and connect the other to the other side of the flange. The second detection voltage supply terminal and the second measurement terminal are connected to detect an abnormality in the zinc oxide tubular element.

In another embodiment of the second embodiment of the present invention, the abnormality detecting device for the surge suppressor comprises a plurality of means for fastening electrically opposed insulating flanges of a metal container filled with high pressure gas. Which is used for each insulating washer of the fastening body of the above, and detects an abnormality of a plurality of zinc oxide tubular body elements whose outer periphery is covered with an insulating tubular body, and includes a step-shaped or pulse-shaped detection voltage generator and , A first detection voltage supply terminal connected to one output of the step detection voltage generation unit via an impedance connected in series, and a second detection voltage supply directly connected to the other output of the step detection voltage generation unit A terminal, a first measurement terminal and a second measurement terminal, and one and the other input are respectively connected to the first and second measurement terminals,
A frequency measuring device for measuring the resonance frequency of the damped oscillation voltage,
A state determination device that compares the resonance frequency value measured by the frequency measuring device with the reference resonance frequency value is provided, and at the time of detection, the first detection voltage supply terminal and the first measurement terminal are connected to one of the flanges, and the other of the flanges is connected. The second detection voltage supply terminal and the second measurement terminal are connected to detect an abnormality in the plurality of zinc oxide tubular elements.

In a specific example of one of the second embodiment of the present invention and other ones, in the abnormality detecting device of the surge suppressing element, the step detection voltage generating section outputs the direct current power source and the output voltage of the direct current power source. It is composed of a switching element that turns on and off.

In a preferred example of one of the second embodiment of the present invention and another example thereof, the abnormality detecting device for the surge suppressor has a reactor connected between the first and second measuring terminals. .

According to the second embodiment of the present invention, as the constitution of the abnormality detecting apparatus for the zinc oxide tubular body element (the zinc oxide tubular body element to be detected) in which the abnormality is detected, In addition to each device of the detection voltage generator and the series impedance, each device of the time constant measuring device and the state determining device is used, or each device of the frequency measuring device and the state determining device is used, Since a general-purpose device can be used for each of these devices, it is possible to detect the abnormality of the zinc oxide tubular element to be detected by using the abnormality detection device having a relatively simple configuration. Even if the abnormality detecting device having a relatively simple structure is used, the abnormality of the zinc oxide tubular element to be detected can be detected accurately at an early stage.

[0031]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic view of the essential portions of a first embodiment of a surge suppression element abnormality detection apparatus according to the present invention.

In FIG. 1, reference numeral 1 denotes a detection voltage generator, 1 ₁
Is a first output end, 1 ₂ is a second output end, 2 is an impedance, 3 is a time constant measuring device, 3 ₁ is a first input end, 3 ₂ is a second
Input terminal, 4 is a state determiner, 5 ₁ is a first detection voltage supply terminal, 5 ₂ is a second detection voltage supply terminal, 6 ₁ is a first measurement terminal, 6 ₂ is a second measurement terminal, 7 is a DC power supply, 8 is a switching element, 9 is one metal container, 9F is a flange of the metal container 9, 10 is the other metal container, and 10F is the metal container 10.
Flange 11 and an insulating spacer 11.

The detection voltage generator 1 is provided with a DC power supply 7
And a switching element 8, one end of the DC power source 7 (positive voltage generating end) is connected to the first output terminal 1 ₁ through the switching element 8, the other end of the DC power source 7 (the negative voltage generating end) is directly second It is connected to the output terminal 1 ₂ . Impedance 2
Are connected in series between the first output terminal 1 ₁ of the detection voltage generator ₁ and the first detection voltage supply terminal 5 ₁ . The second output terminal 1 ₂ of the detection voltage generator 1 is directly connected to the second detection voltage supply terminal 5 ₂
Connected to. In the time constant measuring device 3, the first input end 3 ₁ is connected to the first measurement terminal 6 ₁ and the second input end 3 ₂ is connected to the second measurement terminal 6 ₂ . The input terminal (no figure number) of the state determiner 4 is connected to the output terminal (no figure number) of the time constant measuring device 3.

The metal container 9 on one side and the metal container 10 on the other side adjacent to the metal container 9 are both provided with the flange 9
F and 10F, and both flanges 9F to be joined,
The insulating spacer 11 is interposed between 10F. Although not shown in FIG. 1, the fastening structure between the flanges 9F and 10F is as shown in FIGS. 7 and 8, and the flanges 9F and 10F are shown in FIG. As described above, the fastening with the stud bolt 24, the nut 25, and the first insulating washer 26 is performed at a plurality of positions, and the stud bolt 24, the nut 25, and the second insulating washer 2 are fastened.
It has been concluded with 7. First insulating washer 2
6 is a zinc oxide tubular element 2 as shown in FIG.
7 and an insulating outer cylindrical body 28 that covers the outer periphery thereof.
The insulating washer 27 is composed of an insulating tubular element.

When detecting an abnormality of one or a plurality of zinc oxide tubular elements (a zinc oxide tubular element to be detected) built in the first insulating washer 26, the oxidation to be detected is detected. The first detection voltage supply terminal 5 ₁ and the first measurement terminal 6 ₁ are connected to the flange 9F on which the tubular element made of zinc is arranged, and the second detection voltage is connected to the flange 10F at which the tubular element made of zinc oxide to be detected is arranged. The supply terminal 5 ₂ and the second measuring terminal 6 ₂ are connected.

FIGS. 2A to 2E are waveform diagrams showing the detection voltage supplied to the zinc oxide tubular element to be detected and the decay time constant output from the zinc oxide tubular element to be detected. Where (a) is a detected voltage waveform, (b) is a decay time constant waveform when the detected zinc oxide tubular body element is normal, and (c) to (e) are detected zinc oxide tubular bodies. It is a decay time constant waveform when the abnormality of the element progresses sequentially.

2 (a) to 2 (e), the vertical axis represents the voltage value expressed in volts (V) and the horizontal axis represents the time expressed in microseconds (μs).

FIG. 3 is a characteristic diagram showing the relationship between the resistance value of the zinc oxide element to be detected and the determined decay time constant value.

In FIG. 3, the vertical axis represents microseconds (μs).
Is the decay time constant expressed by, and the horizontal axis is kilo-ohm (kΩ)
It is the resistance value of the detected zinc oxide tubular element expressed by

With reference to FIGS. 2 (a) to 2 (e) and FIG. 3 in combination, the operation (abnormality detection method) of the abnormality detecting device for the zinc oxide tubular element according to the first embodiment shown in FIG. explain.

First, a first detection voltage supply terminal 5 ₁ and a first measurement terminal 6 _{1 are} attached to a flange 9F on which a zinc oxide tubular element (a zinc oxide tubular element to be detected) for detecting an abnormality is arranged.
Are connected to each other, and the second detection voltage supply terminal 5 ₂ and the second measurement terminal 6 ₂ are connected to the flange 10F on which the tubular element made of zinc oxide to be detected is arranged.

Next, the switching element 8 of the detection voltage generator 1 is closed, and the output DC voltage of the DC power supply 8 is applied to the first output terminal 1.
Output from between ₁ and the second output terminal 1 ₂ . This output voltage is supplied to the first detection voltage supply terminal 5 ₁ and the second detection voltage supply terminal 5 ₂ as a step-like detection voltage through the impedance 2 as shown in FIG. It is applied to both ends of each of the tubular elements made of zinc oxide to be detected.

At this time, between the flanges 9F and 10F, the resistance R _{X of} one or more tubular elements made of zinc oxide to be detected and the insulating spacer 11 interposed between the flanges 9F and 10F. And the equivalent inductance L of the ground wire of the one and the other metal containers 9 and 10 are connected in parallel. In addition to this, one or a plurality of detected zinc oxide tubular shapes The capacitance C _X of the body element is also connected to them in parallel.

When a step-like detection voltage is applied between the flanges 9F and 10F, both flanges 9F and 10F
Between F, an equivalent inductance L, an electrostatic capacitance C, an electrostatic capacitance C _X , and a resistance R _X are connected in parallel, and an LCR parallel circuit is connected. The response output of the LC parallel circuit to the step detection voltage is connected. As the waveform, a resonance damping waveform having the resonance frequency of the LC parallel circuit is obtained.

This resonance attenuation waveform is input between the first input terminal 3 ₁ and the second input terminal 3 ₂ of the time constant measuring device 3 via the first measuring terminal 6 ₁ and the second measuring terminal 6 _2. . The time constant measuring device 3 measures the damping time constant of the input resonance damping waveform, finds the value, and supplies the found damping time constant value to the state determining device 4.

Subsequently, the state determining device 4 is the time constant measuring device 3
The decay time constant value supplied from the above is compared with the standard decay time constant value detected by using the zinc oxide tubular element in a good insulating state which is already stored in the built-in memory. Then, the presence or absence of abnormality of the zinc oxide tubular element to be detected and the degree of abnormality are judged from the result of comparison of these two decay time constant values.

That is, as shown in FIG. 2B, when the damping time constant value obtained by the time constant measuring device 3 is large and is almost the same as the standard damping time constant value, the state judging device 4
Determines that no abnormality occurs in all of the one or more detected zinc oxide tubular elements connected between the flanges 9F and 10F.

Further, as shown in FIG. 2C, when the decay time constant value obtained by the time constant measuring device 3 is large but slightly smaller than the standard decay time constant value, the state judging device 4
Any one of a plurality of tubular elements made of zinc oxide to be detected
It is judged that there is a slight abnormality in the individual. In this case, the reason why the decay time constant value becomes small is that the resistance R _X value of the zinc oxide tubular element to be detected having a normal resistance R _X value ( This is because the resistance R _X value is slightly smaller than the resistance value (which is almost infinite), and the decreased resistance R _X value causes the Q of the LC resonance circuit to be dumped.

Further, as shown in FIG. 2 (d), when the decay time constant value obtained by the time constant measuring device 3 becomes moderately small and is considerably smaller than the standard decay time constant value, the state judging device 4 indicates that any one of the plurality of detected zinc oxide tubular elements has a medium abnormality, or
It is determined that a few abnormalities have occurred in several of them. In this case, the reason why the damping time constant value becomes moderate is that the resistance R of one abnormal zinc oxide tubular element to be detected is detected.
_{The X} value gradually decreases according to the degree of abnormality, and the resistance R _X value decreases, and the reduced resistance R _X value causes the Q of the LC resonance circuit to be dumped, or a plurality of detected oxidations that cause a slight abnormality. Each slightly reduced resistance R of the zinc tubular element
_A relatively small resistance R due to the total _X value
This is because it becomes the _X value, and the reduced resistance R _X value causes the Q of the LC resonance circuit to be dumped.

Then, as shown in FIG. 2 (e), when the damping time constant value obtained by the time constant measuring device 3 becomes extremely small and is considerably smaller than the standard damping time constant value, the state judgment is made. The vessel 4 has a large-scale abnormality in any one of a plurality of zinc oxide tubular elements to be detected, for example, an abnormality such as breakage, or several of them each have a medium abnormality. Is determined to have occurred. In this case, the reason why the decay time constant value becomes large on a large scale is that the resistance R _{X of} one detected zinc oxide tubular element having a large abnormality has an extremely small resistance R on the order of several tens of Ω. It becomes the _X value, and the extremely small resistance R _X value causes the Q of the LC resonance circuit to be largely dumped,
Alternatively, the plurality of moderately small resistances R _X values of the detected zinc oxide tubular elements having a medium abnormality are respectively combined into an extremely small resistance R _X value. This is because the extremely small resistance R _X value causes the Q of the LC resonance circuit to be largely dumped.

The comparison between the decay time constant value and the standard decay time constant value in the state determiner 4 is made by storing the decay time constant value in the built-in memory, and then the standard decay time constant also stored in the built-in memory. It is preferable to make a comparison with a numerical value.

The state determiner 4 compares the decay time constant value with the standard decay time constant value, and the decay time constant value is within the range of τ3 to τ2 as shown in FIG. When the difference between the numerical value and the standard decay time constant value is within the range of 90 to 100%, it is determined that the detected zinc oxide tubular element has no abnormality.

The state determiner 4 has a decay time constant value of τ
When the difference between the decay time constant value and the standard decay time constant value is within the range of 60 to 90% within the range of 2 to τ1,
It is determined that the detected zinc oxide tubular element has an abnormality. When the decay time constant value is within these ranges, even if it is determined that the detected zinc oxide tubular element has an abnormality, the detected zinc oxide tubular element that has an abnormality is detected. The body element does not have to be replaced immediately, but can be replaced later at a convenient time.

Further, the state determiner 4 detects the zinc oxide tubular shape to be detected when the decay time constant value is τ1 or less and the difference between the decay time constant value and the standard decay time constant value is reduced to 60% or less. It is determined that a major abnormality has occurred in the body element. At this time, it is necessary to immediately replace the detected zinc oxide tubular element that is abnormal, and if the replacement is neglected, a dangerous state will occur.

As described above, according to the abnormality detecting method of the present embodiment, the detection voltage is applied to the zinc oxide tubular body element to be detected, and the zinc oxide tubular body to be detected is corresponding to the application of the detection voltage. Abnormality of the detected zinc oxide tubular element is detected by finding the damping time constant of the damping voltage at the specified resonance frequency obtained from the tubular element and comparing the obtained damping time constant value with the standard damping time constant value. Therefore, the abnormality of the zinc oxide tubular element to be detected can be accurately detected at an early stage by using a simple detecting means.

Further, according to the abnormality detecting device of this embodiment,
The detection voltage generator, the series impedance, the time constant measuring device, and the status determining device are used.Each of these devices is general-purpose, so it is possible to detect abnormalities in the zinc oxide tubular element to be detected. With a relatively simple device, it is possible to detect accurately at an early stage.

Next, FIG. 4 is a main part configuration diagram showing a second embodiment of a surge suppression element abnormality detection apparatus according to the present invention.

In FIG. 4, 12 is a frequency measuring device, and 12
₁ is the first input end, 12 ₂ is the second input end,
The same components as those shown in FIG. 1 are designated by the same reference numerals.

The difference between the structures of the second embodiment and the first embodiment described above is that the first embodiment uses the time constant measuring device 3, whereas the second embodiment uses the frequency measuring device 12. In addition, there is no difference in structure between the second embodiment and the first embodiment. Therefore, further description of the configuration of the second embodiment will be omitted.

FIG. 5 shows the relationship between the number of zinc oxide tubular elements to be detected used in the second embodiment shown in FIG. 4 and the resonance frequency obtained by the frequency measuring device 12. It is a characteristic diagram.

In FIG. 5, the vertical axis represents megahertz (MH).
z) is the resonance frequency, and the horizontal axis is the number of detected zinc oxide tubular elements.

The operation (abnormality detecting method) of the abnormality detecting apparatus for the zinc oxide tubular element according to the second embodiment shown in FIG. 4 will be described with reference to FIG. In the second embodiment, when fastening the flanges 9F and 10F, a plurality of tubular elements made of zinc oxide to be detected are used.

First, the first detection voltage supply terminal 5 ₁ and the first measurement terminal are attached to the flange 9F on which a plurality of zinc oxide tubular elements (detected zinc oxide tubular elements) for detecting abnormality are arranged. 6 ₁ is connected, and the second detection voltage supply terminal 5 ₂ and the second measurement terminal 6 ₂ are connected to the flange 10F on which the tubular element made of zinc oxide to be detected is arranged.

Next, the switching element 8 of the detection voltage generator 1 is closed, and the output DC voltage of the DC power supply 8 is changed to the first output terminal 1.
Output from between ₁ and the second output terminal 1 ₂ . This output voltage is supplied to the first detection voltage supply terminal 5 ₁ and the second detection voltage supply terminal 5 ₂ as a step detection voltage through the impedance 2 and applied to both ends of a plurality of zinc oxide tubular elements to be detected. To be done.

When a step-like detection voltage is applied between the flanges 9F and 10F, the space between the flanges 9F and 10F becomes
The equivalent inductance L of the ground wire of the one and the other metal containers 9 and 10, the capacitance C by the insulating spacer 11 interposed between the flanges 9F and 10F, and a plurality of tubular bodies made of zinc oxide to be detected. An LCR parallel circuit in which the electrostatic capacitance C _X and the resistor R _X in the element are respectively connected in parallel is connected.

Here, the frequency measuring device 12 applies the step-like detection voltage to determine the resonance frequency of the LCR parallel circuit connected between the flanges 9F and 10F as the first measuring terminal 6 ₁ and the second measuring terminal 6 ₂ and the first input terminal 12 ₁ through the received between the second input 12 ₂ obtains a resonance frequency value received, and supplies the resonant frequency value determined in the state determining unit 4.

Subsequently, the state determiner 4 determines the frequency measuring instrument 1
The resonance frequency value supplied from No. 2 is compared with the standard resonance frequency value detected by using a plurality of tubular elements made of zinc oxide which are already stored in the built-in memory and are in a good insulating state. Then, the presence or absence and the degree of abnormality of the plurality of zinc oxide tubular elements to be detected are determined from the result of the comparison of these two resonance frequency values.

That is, when a plurality (n) of tubular elements made of zinc oxide to be detected are used for fastening between the flanges 9F and 10F, and there is no abnormality in the total number (n), the frequency measuring device is used. If the standard resonance frequency obtained in 12 is f1 MHz, the standard resonance frequency f1 MHz is stored in the built-in memory of the state determiner 4 in advance. Then, if the resonance frequency supplied from the frequency measuring device 12 is f1 MHz as shown in FIG. 5, the state determiner 4 determines that all the detected zinc oxide tubular elements have no abnormality. to decide.

Further, the state judging device 4 is the frequency measuring device 12
As shown in FIG. 5, if the resonance frequency supplied from the device is f2 MHz, which is higher than f1 MHz, x out of the total number n of the zinc oxide tubular elements to be detected are abnormal. Determine that

Here, the reason why the resonance frequency rises when x out of the total number n of the zinc oxide tubular elements to be detected is abnormal is that the abnormal zinc oxide tubular elements to be detected are detected. reduced resistance R _X value of shaped body element, short-circuiting the capacitance C _X of the reduced resistance R _X value abnormality detection target of zinc oxide manufactured by a tubular element produced, these capacitance C _X This is because the LC capacitance is substantially separated from the LC resonance circuit, and the total electrostatic capacitance C _X is reduced accordingly, and the resonance frequency is increased.

As described above, according to the abnormality detecting method of the present embodiment, the detection voltage is applied to the plurality of zinc oxide tubular elements to be detected, and a plurality of the detection voltage are applied in response to the application of the detection voltage. Detecting an abnormality of the zinc oxide tubular element to be detected by obtaining the resonance frequency of the LC resonant circuit including the zinc oxide tubular element to be detected and comparing the obtained resonance frequency with the standard resonance frequency value. Therefore, the abnormality of the zinc oxide tubular element to be detected can be accurately detected at an early stage by using a simple detecting means.

Further, according to the abnormality detecting apparatus of this embodiment,
The detection voltage generator, series impedance, frequency measuring instrument, and status determining instrument are used.Since all of these instruments are general-purpose, compare abnormalities of the zinc oxide tubular element to be detected. With a simple device, it is possible to detect accurately at an early stage.

Further, FIG. 6 is a main part configuration diagram showing a third embodiment of the abnormality detecting apparatus for the surge suppressor according to the present invention.

In FIG. 6, 13 is a reactor,
In addition, the same components as those shown in FIG. 1 are designated by the same reference numerals.

The difference between the third embodiment and the first embodiment described above is that the third embodiment has the first detection voltage supply terminal 5
Reactor 13 between ₁ and the second detection voltage supply terminal 5 ₂
The first embodiment is different from the first embodiment in that the reactor 13 is not connected, and in addition, there is a difference in configuration between the third embodiment and the first embodiment. There is no. Therefore, further description of the configuration of the third embodiment will be omitted.

Regarding the operation and the effect obtained in the third embodiment, since the reactor 13 is connected, the voltage is supplied between the first detection voltage supply terminal 5 ₁ and the second detection voltage supply terminal 5 _2. By using the point where the stepped detection voltage is a detection voltage of a waveform close to a sine wave and the detection voltage of a waveform close to a sine wave, it is possible to detect an abnormality of the zinc oxide tubular element to be detected. The operation is almost the same as the operation and effect obtained in the first embodiment except that it is easy to do. Therefore, further description of the operation and effect of the third embodiment will be omitted.

The abnormality detecting device of the third embodiment is the same as the first embodiment.
Although an example is shown in which the reactor 13 is additionally connected to the abnormality detection device of the embodiment, similarly, even when the reactor 13 is additionally connected to the abnormality detection device of the second embodiment, the abnormality detection device of the third embodiment is shown. It is possible to obtain an abnormality detection device that can exhibit the same function as.

In each of the above-mentioned embodiments, the detection voltage generating unit 1 has been described as an example in which the detection voltage generating unit 1 generates the step detection voltage. However, in the present invention, the detection voltage output from the detection voltage generating unit 1 is It is not limited to the above, but may be a pulsed one.

Further, in each of the above-mentioned embodiments, the detection voltage generating section 1 has been described by taking the example of the configuration including the DC power supply 7 and the switching element 8, but the configuration of the detection voltage generating section 1 in the present invention is not limited to this. However, another configuration may be used as long as it can relatively easily generate the step-shaped or pulse-shaped detection voltage.

[0081]

As described above, according to the abnormality detecting method of the surge suppressor of the present invention, both ends of the zinc oxide tubular body element (the zinc oxide tubular body element to be detected) in which the abnormality is detected are detected. The detection voltage is applied to the
The time constant of the damping voltage at the specified resonance frequency or the resonance frequency of the damping vibration voltage obtained from the detected zinc oxide tubular element is obtained, and the obtained time constant value or resonance frequency value is the standard time constant value or standard resonance, respectively. By comparing with the frequency value, it is possible to detect the abnormality of the zinc oxide tubular element to be detected, and the abnormality of the zinc oxide tubular element to be detected can be detected early by using a simple detecting means. The effect is that it can be accurately detected.

Further, according to the abnormality detecting device of the surge suppressor of the present invention, in addition to the detection voltage generator and the series impedance, each device of the time constant measuring device and the state judging device, or the frequency measuring device and the state judging device. All of these devices are general-purpose, and all of these devices are general-purpose.Therefore, the abnormality of the zinc oxide tubular element to be detected can be detected quickly and accurately with a relatively simple device. The effect is that it can be detected.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing a first embodiment of a surge suppression element abnormality detection device according to the present invention.

FIG. 2 is a waveform diagram showing a detection voltage supplied to a zinc oxide tubular element to be detected and an attenuation time constant output from the zinc oxide tubular element to be detected.

FIG. 3 is a characteristic diagram showing a relationship between a resistance value of a detected zinc oxide tubular body element and a determined decay time constant value.

FIG. 4 is a main part configuration diagram showing a second embodiment of a surge suppression element abnormality detection device according to the present invention.

5 is a characteristic diagram showing the relationship between the number of detected zinc oxide tubular elements used in the second embodiment shown in FIG. 4 and the resonance frequency obtained by a frequency measuring instrument.

FIG. 6 is a main part configuration diagram showing a second embodiment of a surge suppression element abnormality detection device according to the present invention.

FIG. 7 is a configuration diagram showing a state of a joint portion between two metal containers adjacent to each other in a known gas insulated switchgear.

8 is a cross-sectional view showing a detailed configuration of a portion fastened by using a first insulating washer in the coupling portion shown in FIG.

[Explanation of symbols]

1 Detection voltage generator 1 ₁ First output end 1 ₂ Second output end 2 Impedance 3 Frequency measuring device 3 ₁ First input end 3 ₂ Second input end 4 State determiner 5 ₁ First detection voltage supply terminal 5 ₂ 2 Detection voltage supply terminal 6 ₁ First measurement terminal 6 ₂ Second measurement terminal 7 DC power supply 8 Switching element 9 One metal container 9F is a flange 10 of the metal container 9 The other metal container 10F A flange 11 of the metal container 10 An insulating spacer 12 12 is a frequency measuring device 12 ₁ First input end 12 ₂ Second input end 13 Reactor 27 Zinc oxide tubular element

Front Page Continuation (72) Inventor Keisuke Endo 7-2-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Electric Power & Electric Development Division (72) Masatomo Kobayashi 1-chome, Kokubun-cho, Hitachi-shi, Ibaraki No. 1 Stock company Hitachi Kokubun factory (56) Reference JP-A-5-54744 (JP, A) JP-A-8-111917 (JP, A) JP-A-60-249808 (JP, A) Kai 59-154370 (JP, A) JP 11-18221 (JP, A) Actual Kai 1-444478 (JP, U) Actual Kai 1-53975 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) G01R 31/00 G01R 31/12 H01C 7/12

Claims (8)

(57) [Claims] 1. One or a plurality of ones, which are used for an insulating washer of a fastening body that fastens electrically in an electrically insulated state between opposing flanges of a metal container in which a high-pressure gas is sealed, and whose outer circumference is covered with an insulating tubular body. A method for detecting an abnormality of a tubular element made of zinc oxide, wherein a step-shaped or pulse-shaped detection voltage is applied between the flanges, and a time constant of an attenuation voltage of a predetermined resonance frequency obtained between the flanges is obtained. An abnormality detecting method for a surge suppressor, comprising detecting the abnormality of the zinc oxide tubular element by comparing the obtained time constant value with a reference time constant value. 2. The surge suppression according to claim 1, wherein the reference time constant value is a time constant value when abnormality detection is performed using a zinc oxide tubular element in a good state. Element abnormality detection method. 3. A plurality of fasteners used for each insulating washer of a plurality of fastening bodies that fasten electrically in an electrically insulated state between opposed flanges of a metal container in which a high-pressure gas is sealed, the outer circumference of which is covered with an insulating tubular body. A method for detecting an abnormality of a tubular element made of zinc oxide, wherein a stepwise or pulsed detection voltage is applied between the flanges, and a resonance frequency of a damped oscillation voltage obtained between the flanges is obtained and obtained. An abnormality detecting method for a surge suppressor, comprising detecting an abnormality in the plurality of zinc oxide tubular elements by comparing the resonance frequency value with a reference resonance frequency value. 4. The detection voltage is applied between the flanges via an impedance.
Alternatively, the method of detecting an abnormality of the surge suppressor according to the item 3 above. 5. One or a plurality of members, which are used for an insulating washer of a fastening body that fastens in an electrically insulated state between opposing flanges of a metal container in which a high-pressure gas is sealed, and whose outer periphery is covered with an insulating tubular body. A device for detecting an abnormality of a tubular element made of zinc oxide, wherein a detection voltage generating unit for generating a step-shaped or pulse-shaped detection voltage, and an impedance connected in series to one output of the step-shaped detection voltage generating unit. A first detection voltage supply terminal connected via the first detection voltage supply terminal, a second detection voltage supply terminal directly connected to the other output of the step detection voltage generation unit, a first measurement terminal and a second measurement terminal, and 1
One and the other input are respectively connected to the second measurement terminal and a time constant measuring instrument for measuring the time constant of the damping voltage at a predetermined resonance frequency; and a time constant value measured by the time constant measuring instrument as a reference time constant value. And a state determiner that compares the first detection voltage supply terminal and the first measurement terminal to one of the flanges at the time of detection, and the second detection voltage supply terminal and the first measurement terminal to the other of the flanges. An abnormality detecting device for a surge suppression element, comprising connecting two measuring terminals to detect an abnormality of the zinc oxide tubular element. 6. A plurality of insulating cylinders, each of which is used as an insulating washer of a plurality of fastening bodies for electrically fastening between opposed flanges of a metal container in which a high-pressure gas is sealed, and whose outer circumference is covered with an insulating tubular body. A device for detecting an abnormality of a tubular element made of zinc oxide, which is connected to a step-shaped or pulse-shaped detection voltage generator and one output of the step-shaped detection voltage generator via an impedance connected in series. A first detection voltage supply terminal, a second detection voltage supply terminal directly connected to the other output of the step detection voltage generator, a first measurement terminal and a second measurement terminal, and the first and second One and the other input are respectively connected to the measurement terminals, and a frequency measuring instrument for measuring the resonance frequency of the damped oscillation voltage and a state determining instrument for comparing the resonance frequency value measured by the frequency measuring instrument with the reference resonance frequency value. At the time of detection, one of the flanges is connected to the first detection voltage supply terminal and the first measurement terminal, and the other of the flanges is connected to the second detection voltage supply terminal and the second measurement terminal, An abnormality detection device for a surge suppression element, which detects an abnormality of the plurality of zinc oxide tubular elements. 7. The step detection voltage generator comprises a direct current power supply and a switching element for turning on and off the output voltage of the direct current power supply.
Alternatively, the abnormality detection device for a surge suppressor according to the item 6. 8. The surge suppression element abnormality detection device according to claim 5, wherein a reactor is connected between the first and second measurement terminals.