JP2000235082A - Apparatus for detecting thundercloud electric field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an electric field of a thundercloud to determine the possibility of the falling of a thunderbolt, so as to conduct a laser thunder-guiding operation and protection for various electric facilities against an influence of the falling, when the thundercloud gets close to generate the possibility of discharge caused by the falling of the thunderbolt in a specified area. SOLUTION: Detected signals of a wide area electric field change measuring apparatus 1 and a probe end corona current measuring apparatus 2, and a detected signal of an electrostatic field measuring apparatus 3 as an interlock signal are fed to a detecting part 5 respectively to release interlock by getting- close of thundercloud, and electric field is measured by each of the measuring apparatus 1 r 2 or both of them, a shot signal is fed to control part 4 when the change of the electric field exceeds a prescribed threshold value in a detection result measured hereinbefore, and laser thunder-guiding control is operated to conduct dielectric processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thundercloud electric field detection device for transmitting a thundercloud electric field detection signal to a laser lightning device or a protection device of various systems to be protected from the effects of lightning.

[0002]

2. Description of the Related Art Natural lightning includes a cloud-ground discharge in which an initial discharge progresses from a cloud to the ground, and a ground-cloud discharge in which a discharge extends from the ground to a cloud. And winter thunder that frequently occurs on the Sea of Japan side in winter. The time from the initial phenomenon of lightning discharge (the generation of a weak discharge called preliminary breakdown) to the lightning strike is about one hundredth of a second, depending on the altitude of the thundercloud. Cloud-ground discharge occurs in both summer and winter lightning, and ground-cloud discharge is a peculiar lightning phenomenon occurring in Japan along the coast of the Sea of Japan.

[0003] Winter lightning on the Sea of Japan side, particularly in the Hokuriku region, has a low cloud base (1 to 3 km) and a relatively high electric field distribution between the thundercloud and the ground, so that the leader faces the sky from the tip of a high structure. An upward leader is observed. This means
This is a favorable condition for laser lightning, and research on laser lightning is currently being actively conducted for winter lightning.

The concept of laser lightning strike is as shown in FIG.
Install a lightning tower at a predetermined position from the tower and transmission line that you want to prevent lightning, and install a strong, for example, C
Laser light of O ₂ laser is condensed near the tip of the lightning tower by a condensing mirror, a plasma channel is generated by the laser at the tip of the lightning tower, an upward reader is generated from the laser plasma, and lightning is triggered. It is. The electric field concentrates at the tip of the high lightning tower, and the presence of the high electric field generates an upward reader from the laser plasma. The reader extends from the ground to the sky along the laser plasma, shorting the ground and the thundercloud, and neutralizing the lightning charge.

[0005] A number of patent publications, such as Japanese Patent Laid-Open No. 5-180954, disclose a laser lightning arrester conforming to such a basic concept.

[0006]

By the way, the lightning can be predicted in advance by the lightning strike by the laser lightning device or by operating the protection equipment to protect the substation equipment and the radio station in advance. If a high state is known, the prediction information can be used for various purposes. The fact that a thundercloud is approaching a specific area can be known by observing a rain cloud with a radar and measuring the electric field of the thundercloud within a predetermined range.

[0007] However, even if the thundercloud advances within a predetermined area of a specific area, there is a high possibility that the thundercloud will actually strike a building or the like. At that time, it is not possible to detect whether the protective equipment should be activated by simply monitoring the electric field of the thundercloud. In particular, when laser lightning is performed, factors that determine the timing of laser irradiation include a thundercloud growth degree, an increase in ground electric field, and an increase in corona current.

However, conventionally, since the irradiation timing of these elements is empirically determined by an operator while monitoring the numerical values of these elements, it is possible to objectively and reliably perform lightning strike and operate the protection device. The timing could not be known, and it was not possible to respond properly if the state of the thundercloud changed suddenly. Further, the laser lightning method and apparatus proposed in the various patent publications described above merely describe an improvement in the basic configuration of how to reliably realize laser lightning.

SUMMARY OF THE INVENTION In view of the above-mentioned various problems, the present invention sets a threshold value based on a change in the electric field of a thundercloud when a thundercloud approaches a specific area, detects the possibility of the thundercloud, and performs laser-induced lightning. It is an object of the present invention to provide a thundercloud electric field detection device capable of obtaining a timing signal for protection of various electric facilities.

[0010]

According to the present invention, there is provided an electric field change measuring device for measuring a change in an electric field of an electromagnetic wave emitted by a thundercloud predischarge, and a measuring signal from the measuring device. A detection unit for detecting an electric field of a predetermined value or more and outputting a signal, wherein the measuring device is a measuring device for measuring a change in the electric field with a time resolution of a unit of microsecond or less, and Thus, a thundercloud electric field detecting device is configured to output an output signal when a change in the electric field value exceeding a predetermined electric field threshold is detected a plurality of times within a time interval of several milliseconds to several milliseconds.

As means for solving the above problems, an electric field measuring device for measuring an electric field of an electromagnetic wave emitted by a precursor discharge of a thundercloud, and a thundercloud having a predetermined value or more is detected from a measurement signal of the measuring device to output a signal. And a detector, wherein the measuring device is m
A thundercloud field measuring device that measures changes in electric field with a time resolution of seconds, and outputs an output signal when the detector detects that the detection signal has exceeded a predetermined threshold at any time during the measurement. It can also be a detection device.

Alternatively, an electric field change measuring device for measuring a change in an electric field of an electromagnetic wave emitted by a precursor discharge of a thundercloud, and a detecting device for detecting a thundercloud having an electric field of a predetermined value or more from a measurement signal of the measuring device and outputting a signal. A first unit for detecting a change in an electric field with a time resolution of a unit of μ seconds or less.
An electric field change measuring device and a second electric field change measuring device for detecting a change in an electric field with a time resolution of a unit of milliseconds. Output when detecting either multiple changes of the electric field value exceeding the predetermined electric field threshold value within the interval, or detecting that the electric field value exceeds the predetermined threshold value at any time of measurement, or both. A thundercloud electric field detection device configured to output a signal may be used.

Any of the detection devices of the above three inventions detects a change in the electric field when a thundercloud approaches, and outputs a shot signal. The first invention detects whether there is a possibility of a lightning strike when the electric field condition fluctuates rapidly while a thundercloud develops, and detects whether or not a predetermined limit value has been exceeded. Since a PB (Preliminany Breakdown) discharge is repeatedly emitted from such a thundercloud, the possibility is judged by the electric field change. Since the electric field change measuring device operates with a time resolution of the order of microseconds or less, the electric field value detected with such a minute resolution may exceed the threshold value several times within the measurement time of m seconds to several milliseconds. If it can be detected, the possibility of a lightning strike can be determined.

The second invention is also a device for detecting the possibility of a lightning strike. In this case, since the electric field change measuring device has a time resolution of the order of milliseconds, the electric field of the thundercloud is slower than the measuring device of the first invention. It is suitable for measuring the case where changes occur.

According to a third aspect of the present invention, both of the first and second aspects of the present invention are provided with electric field change measuring devices having different types of characteristics, and an output signal is output by detecting one or both of them. ing.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic diagram of an example in which a thundercloud electric field detection device A of the embodiment is connected to a laser lightning device B. 1 is a broadband electric field change measuring instrument (slow antenna),
2 is a needle end corona current measuring device, 3 is an electrostatic field measuring device (field mill), and 4 is a laser controller. FIG. 2 shows a block diagram of the thundercloud electric field detection device A. The detector 5 detects an electric field change or an electrostatic field value from a measurement signal of each measuring instrument.

The electric field change measuring device 1 comprises an electric field antenna section 1a made of a metal disk and an amplifier 1b for amplifying the measurement signal, and measures the electric charge induced on a flat plate by a thundercloud to obtain the intensity of the vertical component of the ground electric field. Is obtained in proportion to. This measuring instrument 1 has a time resolution of μ second unit. The detecting unit 5 detects an electric field change for a measurement signal of the measuring device 1 for a measurement time interval of 10 ms, and three electric field changes exceeding a threshold level (ground electric field value) 1.0 kV / m within the measurement time. An electric field change detector 5a that outputs a shot signal when counted is included.

The corona current measuring device 2 has a needle-like electrode portion 2a.
And an amplifier 2 for amplifying the corona current flowing through this electrode section
b) to measure the corona current induced in the needle-shaped electrode portion 2a by the thundercloud to measure the electric field between the thundercloud and the ground. This measuring device 2 has a time resolution of the order of milliseconds. The detecting unit 5 does not provide the setting of the time width or the number of counts with respect to the measurement signal of the measuring device 2, and outputs the shot signal when the current value becomes equal to or more than the predetermined threshold value 20 μA at any time during the measurement. 5b.

The electrostatic field measuring device 3 is for detecting the approach of a thundercloud, and is not limited to a device using a Pockels element or an interferometer as long as it can measure an electrostatic field regardless of its type. Good. The detection unit 5 includes an electrostatic field detection unit 5c that outputs a shot signal when an electrostatic field value measured by the measuring device 3 exceeds a threshold value of 15 kV / m.

The measuring signals of the above three measuring instruments 1 to 3 are respectively inputted to the detecting section 5, and the signal from the measuring instrument 3 is a signal interlocking any malfunction of the two measuring instruments 1 and 2. As long as the signal from the measuring device 3 is not input, the detection unit 5 does not output the output signal even if one or both signals of the measuring devices 1 and 2 are input. . The shot signal from the detection unit 5 is input to the laser control unit 4, and the control unit 4 drives the laser lightning device B.

The laser lightning striker B shown in FIG. 1 is for reflecting and condensing the laser light from the laser generator 11 linearly and vertically in the vertical direction by the condenser mirror 12, and grounding the lightning strike from the thundercloud to the ground. The insulated target 14 provided on the top of the lightning tower 13 is irradiated with the condensed laser light to generate a continuous plasma channel, and a leader grown from the laser plasma guides the thundercloud to the lightning tower 13. Has become.

In the above example, the laser lightning arrester B has an insulating target provided above the lightning arrester 13. However, unlike the conventional laser lightning arrester, there is no solid object above the lightning arrester 13. A method of generating a spatial plasma by condensing a laser beam in an upper space without providing a target may be used. However, such conventional laser lightning strikers have poor spatial plasma generation efficiency, and in many cases, the reader does not reach the thundercloud. I do.

The thundercloud electric field detecting device A configured as described above
The operation of the embodiment provided with the laser lightning device B is as follows.

Whether or not the thundercloud K is approaching a specific area is monitored by a radar in the same manner as in the prior art. As a result, when the thundercloud K approaches, the power of the devices A and B is turned on to start measuring the electric field state of the thundercloud.

The measurement of the electric field state is first performed by the electrostatic field measuring device 3 to determine whether the electrostatic field of the thundercloud K exceeds a predetermined threshold level of 15 kV / m. Even if the corona current measuring device 2 outputs a shot signal due to a malfunction, no output signal is output from the detecting section 5.

The above-mentioned threshold value of the static electric field is a static electric field value at a lower limit of a thundercloud that develops from a thundercloud and has a possibility of lightning strike. If the threshold value is exceeded, the electric field value is not high enough to cause a lightning strike immediately. However, if the threshold value is exceeded, there is a possibility of a lightning strike from the thundercloud. Therefore, the signal from the electrostatic field measuring device 3 is sent to the detecting unit 5 in parallel with the measurement signals from the measuring devices 1 and 2, and the interlock is released. Is done.

Therefore, as a result of the measurement by the measuring devices 1 and 2,
If the measurement signal in any one of the measuring devices 1 and 2 or both exceeds the threshold value of each of the measuring devices 1 and 2, the detecting section 5 outputs a shot signal. In this case, the measuring device 1 measures time 1
If an electric field change exceeding the threshold level of 1.0 kV / m is counted three times within 0 ms, the electric field of the thundercloud may be a lightning strike, and it is in a state in which a lightning strike is performed to avoid a lightning strike. And a shot signal is output.

When the measuring instrument 2 measures that the corona current, which is the above-mentioned predetermined threshold value, has passed 20 μA or more,
Similarly, it is determined that lightning should be avoided, and a shot signal is output. As described above, when each of the two measuring devices 1 and 2 detects the possibility of a lightning strike, a shot signal is output from the detecting section 5 by one or both of the detection signals. 2 detects a state in which the electric field change of the thundercloud differs according to each characteristic.

Since the measuring instrument 1 can detect the electric field change with a time resolution of the order of microseconds as a function of detecting the change of the electric field, it detects the change exceeding the threshold value within the predetermined measurement time in the order of microseconds, and the electric field of the thundercloud rapidly changes. A state that is changing can be detected.
This is the case when thunderclouds are developing rapidly. PB discharge (Preliminany Breakdowow) from such a fluctuating thundercloud
n) is released repeatedly and the repetition time is 4-50
Repeated several times in μ seconds.

The electromagnetic wave of the PB lightning signal is measured by the measuring device 1 in units of μ seconds, and the timing is set so as to output a shot signal when the threshold value is exceeded three times (a plurality of times). Since the shot signal can be used as the trigger signal of the above, the malfunction of the lightning operation is reduced, and the idle operation of the laser lightning device can be prevented. or,
Since the PB discharge signal is emitted in the initial stage of the lightning phenomenon, there is an advantage that the laser-induced lightning operation can be performed in the initial stage.

On the other hand, even if there is a PB discharge, it is not always possible for the measuring instrument 1 to detect from the PB discharge signal a state in which it is determined that it is time to trigger laser lightning at the initial stage of the lightning phenomenon. In some cases, the change in the electric field may be a slow change on the order of milliseconds, but the timing for triggering the laser may be necessary. In such a case, the measuring device 1 may not always be able to detect the change in the electric field, and therefore, the measuring device 2 is provided to cope with such a case.

This measuring device 2 has a time resolution of a millisecond unit, and as shown in FIG. 4, integrates a corona current flowing through a needle probe under the influence of an electric field change fluctuated by a PB discharge, and integrates the corona current. If the value exceeds a predetermined threshold, the reader due to the PB discharge is not caused by a sudden change in the unit of μ seconds, but it is determined that the fluctuation width exceeds the predetermined level.

Accordingly, although the electric field change is slow in time, the fluctuation width is large, and it is possible to detect the timing at which laser lightning should be performed. However, when the thundercloud develops rapidly with this measuring device 2, the change may not be able to be caught at a good timing, and a malfunction may occur.

When the electric field state of the thundercloud is detected as described above and a shot signal is output from the detection unit 5 to the laser control unit 4, the laser control unit 4 responds to the shot signal.
Transmits a control signal to the laser generator 11 of the laser lightning trigger B to perform laser lightning. In the laser lightning strike device B, as described above, a continuous plasma channel is generated at the target 14 at the tip of the lightning tower 13, and the generated leader extends to the thundercloud, guides the electric charge of the thundercloud to the lightning tower 13, and causes lightning. Is performed.

In the above-described embodiment, the measurement signals of the three measuring devices 1, 2, and 3 are input to the detecting section 5, and the signal of the measuring device 3 is used as an interlock signal and one or both of the measuring devices 1 and 2 are used. It is assumed that the detection signal is output from the detection unit 5 in accordance with the detection signal described above. However, as the electric field detection device, the measurement device 1 and its detection unit 5a or the measurement device 2 and its detection unit 5b each having a single detection function, The measuring device 3 and its detecting section 5c may be combined with a single detecting device. Each single detection device can detect a change in the electric field state of lightning according to each characteristic.

Although the thundercloud electric field detecting device A of the above embodiment detects and transmits the timing signal of laser lightning to the laser lightning device B, other than such use, various electric equipment may generate electromagnetic noise or noise. A control signal can be sent to a high-speed protection device for protection from the effects of lightning, which can be used to protect electrical equipment. In a facility building (for example, a radio station) or the like, if high surge voltage is induced (or lightning strikes) due to electromagnetic noise such as lightning, the equipment is damaged. Therefore, measures against high voltage of the equipment have been taken. However, if the surge high voltage and the like can be predicted in advance and the intrusion of abnormal voltage can be prevented, there is an advantage that the design of equipment and the like and the specifications of equipment can be greatly reduced.

For example, as shown in FIG. 5, a radio antenna 23 is provided on a support 22 above a building such as a facility building (for example, a radio station). In order to prevent the influence of lightning, a high-speed protection device 24 is provided on the wireless antenna 23, and a control signal of the thundercloud electric field detection device A is sent to this device to use for protection of equipment.

When a control signal that detects the possibility of a lightning strike is sent from the thundercloud electric field detection device A to the high-speed protection device 24,
The control signal switches a switch in the high-speed protection device 24 to ground the PB discharge electromagnetic wave signal from the wireless antenna 23 to the ground via the ground wire 25 so that the noise signal does not directly affect the wireless station. Protect. The equipment to be protected includes various facilities besides radio stations.

[0039]

As described in detail above, the first aspect of the present invention is as follows.
According to the invention of the present invention, an electric field change measuring instrument having a time resolution of microsecond unit measures an electric field change of an electromagnetic wave due to a PB discharge of a rapidly developing thundercloud, and outputs a detection signal as a possibility of lightning strike when exceeding a predetermined threshold value a plurality of times. As a result, it is possible to obtain a timing signal for activating a laser lightning strike or a protective device, and to ensure a reliable trigger signal that helps to minimize damage from lightning strikes and the effects on various electrical equipment. There is an effect that it can be provided as a material having a shape.

In the second invention, since the electric field change due to the PB discharge is measured by the electric field change measuring device having a time resolution of a unit of millisecond, it is detected that the electric field value exceeds a predetermined threshold value at an arbitrary time during the measurement. By doing so, the possibility of lightning strike can be determined, and a detection signal suitable for detecting a slower electric field change than in the first invention can be obtained.

In the third invention, the electric field change measuring devices of the first and second inventions and the respective detecting sections are provided.
An advantage is obtained in that the measuring device of the second invention can detect the electric field change that changes more slowly than the first invention and can output a more reliable and reliable trigger signal.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of an example in which a thundercloud electric field detection device according to an embodiment is applied to a laser lightning device;

FIG. 2 is a schematic block diagram of a thundercloud electric field detection device.

FIG. 3 is an explanatory diagram of the measurement and detection operations of the broadband electric field change measuring instrument.

FIG. 4 is an explanatory diagram of measurement and detection operations of a needle end corona current measuring device.

FIG. 5 is an explanatory diagram of an application example to a high-speed protection device.

FIG. 6 is a conceptual diagram of a laser lightning strike.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Broadband electric field change measuring device 2 Needle end corona current measuring device 3 Electrostatic field measuring device 4 Laser control unit 5 Detecting unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuji Ishikubo 3-3-22 Nakanoshima, Kita-ku, Osaka City Inside Kansai Electric Power Co., Inc. (72) Mikio Adachi 3-2-2, Nakanoshima, Kita-ku, Osaka-shi Inside Kansai Electric Power Co., Inc. (72) Inventor: Shigeaki Uchida 1-8-4, Utsumotocho, Nishi-ku, Osaka City Inside the Institute for Laser Technology Research (72) Inventor: Yoshinori Shimada 1-8-4, Utsumotocho, Nishi-ku, Osaka-shi No. Within the Foundation Laser Technology Research Institute (72) Inventor Tatsuhiko Yamanaka 1-8-4 Nishihoncho, Nishi-ku, Osaka City Inside the Foundation Laser Technology Research Institute (72) Inventor Chiyoe Yamanaka 1-chome, Nishi-ku, Nishi-ku, Osaka City No. 8-4 F-term in the Laser Technology Research Institute (reference) 5G067 EA01

Claims (4)

[Claims] An electric field change measuring device for measuring a change in an electric field of an electromagnetic wave emitted by a precursor discharge of a thundercloud, and a detecting device for detecting a thundercloud having an electric field of a predetermined value or more from a measurement signal of the measuring device and outputting a signal. The measuring device is a measuring device that measures a change in an electric field with a time resolution of a unit of μ seconds or less, and a detecting unit detects a change in an electric field within a time interval of several milliseconds to several milliseconds from a measurement signal of the measuring device. A thundercloud electric field detection device, which outputs an output signal when a change in the electric field value exceeding a predetermined electric field threshold is detected a plurality of times. 2. An electric field measuring device for measuring an electric field of an electromagnetic wave emitted by a precursor discharge of a thundercloud, and a detection unit for detecting a thundercloud having a predetermined value or more from a measurement signal of the measuring device and outputting a signal, The measuring device is a measuring device that measures a change in an electric field with a time resolution of a unit of millisecond, and outputs an output signal when a detecting unit detects that a detection signal exceeds a predetermined threshold value at an arbitrary time during the measurement. Thundercloud electric field detection device. 3. An electric field change measuring device for measuring a change in an electric field of an electromagnetic wave emitted by a thrust cloud precursor discharge, and a detection for outputting a signal by detecting a thundercloud having an electric field of a predetermined value or more from a measurement signal of the measuring device. A first electric field change measuring device for detecting a change in the electric field with a time resolution of μ seconds or less, and a second electric field change measuring device for detecting a change in the electric field with a time resolution of m seconds From the measured values of these measuring instruments, each detecting unit detects a change in the electric field value exceeding a predetermined electric field threshold a plurality of times within a time interval of several milliseconds to several milliseconds, or performs any arbitrary measurement. A thundercloud electric field detecting device configured to output an output signal upon detecting either or both of detecting that an electric field value exceeds a predetermined threshold value in time. 4. An electrostatic field measuring device for measuring an electrostatic field of a thundercloud, and an electrostatic field detecting section for detecting a thundercloud having an electrostatic field of a predetermined value or more from a measurement signal of the measuring device and outputting a signal, and 2. A detection signal from a detection unit of an electric field change measuring device for detecting an electric field of an electromagnetic wave is output or blocked to the outside by the detection signal of the electrostatic field measuring device.
4. A thundercloud electric field detection device according to any one of claims 1 to 3.