JPH0132959B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a highly accurate lightning warning system. [Prior art] Conventional lightning warning systems include (1) radar type, (2)
There are radio wave type and (3) electric field type. [Problems to be solved] (1) The radar method can measure the size and height of thunderclouds with relatively high accuracy, and can be fully used to predict the occurrence of lightning. There are problems in that it does not directly measure electric charge, discharge, etc.), and in practice, the equipment is large-scale and costs several tens of times more than the (2) radio wave method and (3) electric field method. . (2) Radio-controlled systems are susceptible to interference, for example due to reflections from the ionosphere, which tends to make distant thunderclouds appear nearby. Another problem was that it could operate even in the final stage of lightning, when only intercloud discharge occurred. (3) In the electric field method, the strength of the electric field depends on the space charge accumulated near the ground surface, so it may be difficult to judge using an electric field strength measuring device alone. In addition, systems that integrate instantaneous sudden changes in the electric field value over a certain period of time and issue an alarm when the number of occurrences exceeds a set value catch lightning at a relatively short distance, but they detect lightning before it starts discharging. is unsuitable for
All of them had practical drawbacks, such as the difficulty of adjusting the setting values. [Means to solve the problem] The ultimate purpose of the lightning warning system is to ``do not work when there is no risk of a lightning strike, and always work when there is a risk of a lightning strike.'' Both design and adjustment are required. It is about tying things together. As a result of measuring electric fields during thunderstorms over many years, the present inventor overcame the shortcomings of the electric field method. First, the inventor measured the ground electric field value, accumulated the number of instantaneous sudden changes in the electric field value over a specified period of time, and calculated the number of instantaneous sudden changes in the electric field value. Detects when the ground electric field increases beyond a set value, and also separately detects fluctuations in the slowly changing component of the ground electric field, that is, low frequency ground electric field values,
This paper proposes a highly accurate lightning strike warning system that uses a combination of these pieces of information as the activation factor and uses an electric field strength measurement method. In this specification, the electric field near the earth's surface is abbreviated as "ground electric field." First, if we look at the changes in the ground electric field and the instantaneous sudden changes in the ground electric field value as the thundercloud advances, we can see that at points far from the thundercloud, the direction of the electric field changes as shown in Figure 2, which shows a typical thundercloud. downward

[Formula]. Although the value is considerably larger than that under clear skies (about -100v/m), it is not so strong. In addition, directly below the thundercloud, the upward direction is more than 10 KV/m. Therefore, the electric field becomes zero at the intermediate point. If the thundercloud moves as shown by the arrow in Figure 2, it will move downward at the point.

From [Formula], zero potential and and then upward

〔Example〕

Next, an embodiment of the lightning warning device according to the present invention will be described with reference to the drawings. In the embodiment shown in FIG. 1, reference numeral 1 denotes a surface electric field strength measuring instrument used for the purpose of measuring the surface electric field value. For this purpose, a rotating field strength measuring device (field mill) or a needle electrode for corona generation is used. 2 is a sudden change sensor, 2' is a sudden change occurrence number integration circuit, sensor 2 detects a sudden change in the ground electric field, and integration circuit 2' is a predetermined value when the change value exceeds a predetermined value (width). This is to add up the number of occurrences within a period of time. As the sensor 2, a stationary plate electrode for electrostatic induction sensing is used. 3 is a ground electric field value detection circuit that detects that the ground electric field value exceeds a predetermined value. 4 is a low-frequency fluctuation in the ground electric field of 0.3 seconds to several seconds.
The fluctuation value when it appears repeatedly with a period of about 10 seconds (with low frequency fluctuations) exceeds 10 millivolts when the sensor is a field mill, and 10 microamps or more when using a corona electrode (value measured directly at the sensor part). This is a low frequency fluctuation number integration circuit that integrates the number of objects over a predetermined period of time. Reference numeral 5 is an over circuit in which either the input from the ground electric field value detection circuit 3 or the integration circuit 2' is
When the predetermined value is exceeded, the caution alarm transmitter 6 is activated. Reference numeral 7 is an AND circuit which operates the warning alarm transmitter 8 when the inputs from the ground electric field value detection circuit 3 and the integration circuit 2' both exceed a predetermined value. 9 is a second power circuit, and the ground electric field value detection circuit 3 operates the lightning warning transmitter 10 when the input from the low frequency fluctuation number integration circuit 4 significantly exceeds a predetermined value. The phrases "cautionary warning", "cautionary warning", and "lightning warning" mean that multiple levels of warning can be issued depending on the probability of a lightning strike; for example, the expressions "cautionary warning,""evacuationwarning," and "emergency warning" also mean the same thing. It is. An amplifier is used as a detector to detect sudden changes in the ground electric field value, and a stationary plate electrode for electrostatic induction sensing that can detect changes in the electrostatic field is used as a sensor. The embodiment shown in FIG. 6 shows a more specific device. The structure is basically the same as that of the embodiment shown in FIG.
A hemispherical electrode plate 2 corresponding to the sudden change sensor is provided via the holder, and this is mounted on a mounting base. A microammeter 90 with a relay contact and a relay 91 are connected to the needle electrode 1 for corona generation. This microammeter 90 has a zero point at the center and setting needles on both sides.The corona current is measured, and depending on the magnitude and polarity of the ground electric field value, the setting needle operates a relay 91, causing fluctuations in the ground electric field value. can be detected. In other words, it functions as the ground electric field value detection circuit 3 and the low frequency fluctuation number integration circuit 4, and can obtain the respective signals. A rapidly changing integrator 2' is connected to the hemispherical electrode plate 2. The integrator 2' has a sudden change occurrence number integration circuit. With this configuration, it is possible to obtain signals of the ground electric field value exceeding the set value, the number of sudden changes, and the number of low frequency fluctuations. oscillators 6, 8, 10 of each stage via the AND circuit 7)
A predetermined alarm will be issued. Note that numerals 14, 15, and 16 in FIG. 6 are timers. As explained in the above embodiment, an amplifier is used as a detector to detect sudden changes in the ground electric field value, and a stationary plate electrode for electrostatic induction sensing that can detect changes in the electrostatic field is used as a sensor. It will be done. A sudden change in the ground electric field value refers to, for example, a change in induced voltage of 10 millivolts or more within a time of 0.001 seconds or less. On the other hand, the detector for detecting low-frequency fluctuations in the ground electric field value uses a DC amplifier and a microammeter with a zero point at the center and setting needles on both sides. In this case, the sensor may be a rotating electric field strength measuring device or a needle electrode for corona generation. The low frequency electric field value is the value that is directly sensed by the above sensor, and the voltage or current value is 10 millivolts or more for a rotating electric field strength measuring device, or 10 microamperes or more for a corona generation needle electrode.
This refers to a case where there is a gradual change of about 0.3 seconds to 10-odd seconds (Figure 3 b). When low-frequency electric field fluctuations occur continuously and periodically, especially active thunderclouds are approaching A in the diagram.
There are many cases in this area. Sudden changes in the ground electric field value, as shown in a and b in the figure, are also mixed, but since they are detected by a microammeter with a relay contact, changes with a width of less than 0.3 seconds cannot be detected due to the structure of the microammeter, so it is easy to detect both. can be distinguished and used as an element for lightning strike determination. A detailed study called the "Thundercloud Project" was conducted in the late 1940s under the direction of the famous meteorologist Byers. According to this, thunderclouds are formed by three clouds as shown in Figure 5.
They are taught to go through a stage of growth. During the process of thundercloud formation, when the cloud top exceeds the freezing altitude, echoes begin to appear on radar. That was the childhood of thunderclouds. After that, in 10-15 minutes, the diameter was 5-10km, the height was 7-9.
It develops to about Km. All air currents within a cloud are updrafts, and are strongest near the center. Air currents are not limited to converging air currents on the ground, but surrounding air is also drawn in from the sides of the cloud. When you cross it by plane, precipitation is observed, but it is supported by rising air currents and does not fall below the cloud base. As the thundercloud continues to develop and the cloud top becomes higher, the ice particles and water droplets generated in the updraft become large and cannot be supported by the air current and begin to fall to the ground. This period marks the beginning of the adult phase, and the cloud shape can be observed as a sharp cumulonimbus cloud. The way electrical charges are distributed in thunderclouds, which generate huge spark discharges and lightning discharges, is that during the mature stage of summer, positive charges spread to the upper layer of the cloud, and negative charges spread to the upper layer of the cloud. -20℃～
It is relatively densely distributed in the -30℃ range. This is because the fine ice crystals that are carried by the updraft have a positive charge, and the large ice crystals that fall due to gravity have a negative charge that separates. Become. In order to separate and accumulate this charge, a force is needed to overcome the electric force that attracts the positive and negative and separate them, but this force generates a large amount of large hail particles with a radius of 5 mm or more. It becomes an effective force only in the clouds. In other words, the formula of charge separation-power generation is established, and lightning occurs. The above research report shows that the lightning warning system of the present invention is suitable and corresponds well to the development of thunderclouds affected by updrafts. [Effects] The lightning warning device of the present invention has the above-described configuration, and uses both the method of integrating instantaneous sudden changes in the ground electric field value and the ground electric field value, so it can detect lightning strikes in mountainous areas, etc. It can be used effectively even in places where lightning occurs (places where lightning is extremely close). Furthermore, we focused on the fact that low-frequency fluctuations in the ground electric field value are closely related to the growth process of thunderclouds, and incorporated them into one of the warning elements. It is possible to issue a highly accurate, reliable, and reliable warning that is always activated when there is a risk of danger. As for the adjustment, once each set value is set, caution warnings, warnings depending on the purpose of use (for example, evacuation orders), and lightning warnings can be automatically issued step by step without any particular judgment. The lightning warning device of the present invention is highly reliable and economical, can deal with all types of lightning, and can be called an epoch-making invention useful for protecting valuable property and precious human lives from lightning strikes.

[Brief explanation of drawings]

FIG. 1 is a wiring diagram showing a basic embodiment of a lightning warning device according to the present invention. FIGS. 2 to 5 are explanatory diagrams regarding thunderclouds, and FIG. 2 is an observation diagram showing the electric field distribution on the ground due to a typical thundercloud. Figure 3 is a schematic diagram showing changes in the ground electric field value when observed at the points in Figure 2;
Figure 3b shows the occurrence of overall changes and sudden changes in the ground electric field value due to the approach of thunderclouds, and Figure 3b shows the case where low frequency components appear prominently around the range indicated by A in Figure 3a. It is. Figure 4 is a schematic diagram of the charge distribution within an adult thundercloud. Figure 5 is a schematic diagram of a single-cell thundercloud in its childhood, adulthood, and decline stages. 6th
The figure is a wiring diagram showing another embodiment of the present invention. Brief explanation of the symbols 1...Sensor for measuring ground electric field value (needle electrode for corona generation), 2...Sensor for detecting sudden changes in ground electric field value (hemispherical electrode plate), 2'...Sudden change occurrence number integration circuit (sudden change (integrator), 3... Ground electric field value detection circuit, 4... Low frequency fluctuation number integration circuit, 5
...Ower circuit, 6...Caution alarm transmitter, 7...AND circuit, 8...Warning alarm transmitter, 9...Second Ower circuit, 10...Lightning warning transmitter.

Claims (1)

[Claims] 1. In a lightning warning device using electric field strength measurement method,
A stage in which one of the ground electric field value and the cumulative number of occurrences of sudden changes in the ground electric field value within a predetermined time exceeds a set value, a stage in which both exceed the set value, and a stage in which the above-mentioned A lightning strike warning device capable of issuing a warning in multiple stages, including a stage when the ground electric field value becomes extremely large or a stage when a low-frequency fluctuation in the ground electric field value different from the sudden change occurs. Sensors such as a rotating electric field strength meter (field mill) that measures the ground electric field value or a needle electrode for corona generation. A sensor that detects sudden changes in the ground electric field value and a sudden change occurrence count integration circuit that adds up the number of sudden changes that are greater than or equal to a predetermined value within a predetermined time. A circuit that detects low-frequency fluctuations in ground electric field values.