JPS6027883A - Approach of thunderbolt detection system - Google Patents

Abstract

PURPOSE:To enable the switching off of a power source circuit or the like immediately before a thunderbolt is anticipated by detecting the approach of the thunderbolt positively checking the approach of the thunderbolt point according to a sharp inversion of the surface electric field. CONSTITUTION:Negative corona current increases in response to the approaching of a thundercloud and a approaching thunderbolt and with a sharp inversion of the surface electric field, positive corona current increases to actuate relays 7 and 8 having a holding circuit through a meter relay 4 and negative and positive current contacts 5 and 6. As these relays 7 and 8 continue to operate, a relay 9 starts to give an alarm about the access of the thunderbolt point. Thus, the access of the thunderbolt can be detected positively to enable the switching off of the power source circuit of a computer immediately before a thunderbolt is anticipated.

Description

[Detailed Description of the Invention] Normal case. between the base of the lightning cloud and the ground surface. It is known that there is a space charge with the opposite polarity to the charge at the cloud base.

If these situations are expressed using electric lines of force, the result will be as shown in Figure 1 (assuming that the base of the cloud has a negative charge). The symbol - in the figure represents the negative charge of the cloud. O is empty 1% III charge.

+ indicates the ground surface charge 6↑ as electric lines of force. Compared to the ground surface potential. This is due to the strong slope of the electric potential just below the cloud base due to the effect of space charge, and the fact that the atmospheric pressure decreases as you get higher up in the sky. The leader often launches from the base of the cloud. On the other hand, the strength of the electric field is. The higher the density of the electric lines of force, the stronger they become. Even just before a lightning strike, the ground electric field does not become very strong at about 10 KV/II, as shown in Figure 2. If lightning strikes from that cloud. Although the negative charge of the cloud decreases rapidly. The space charge distribution does not change immediately (some of it is neutralized by the downward discharge path that leaves the discharge path during a lightning strike). Since the earth is a conductor, a charge appears immediately, and the electric field on the earth's surface reverses as shown in the figure and becomes quite strong.

Next, we will use concrete mathematics to explain this principle in an easy-to-understand manner. For example, assume that the distance between the cloud base and the ground is IKm, and the potential difference between the ground and the cloud base is approximately 100 million volts.

If there is no space charge. The actual measured value Xo of the electric field value X on the earth's surface is about 1♂V/m. The difference is X X6=
9×IOV/m.

In reality, there is a space charge, so if the reverse electric field on the earth's surface based on that space charge is υ, then flX) is the difference value 9×
1♂v/m (x-(x)fJs Actual ground electric field value The ground electric field caused by this is approximately 90,000 V/m in the opposite direction.Therefore, compared to the electric field immediately before a lightning strike, it generates a considerably stronger electric field in the opposite direction. A fairly large corona current in the opposite direction is generated. Expressed in concrete numbers. Surface electric field X6 before the lightning strike
= I x compared to the corona current by 10V/m.

From (X), it changes to a corona current in the opposite direction due to the space charge of the opposite sign of x11v/m. Its absolute value becomes quite large (in reality, the charge at the base of the cloud does not become completely zero).

The space charge is also partially neutralized, so the value is smaller than the calculated value).

Then, as time passes, the charge at the cloud base increases.

Space charge is temporarily reduced by diffusion or absorption by the ground. The value of X6 gradually decreases, passes through 6 zero values, and returns to the value immediately before the lightning strike. At this point, it is thought that the space charge increases again due to corona discharge generated from plants and buildings on the ground surface, and the value of (x) x xo also returns to the state before the lightning strike.

Detecting the sudden reversal of the ground electric field during a lightning strike as described above indicates that the lightning strike point is close to each other. It is possible to warn of the danger of lightning.

Where can the present invention be most effectively utilized? Signal lines including computers and other light electrical equipment. Cut off the power,
As in the case of preventing destruction from lightning strikes. It would be inconvenient to cut the lines too early, so it is desirable not to cut them until the last minute, but to cut the lines just before the danger of being struck by lightning is imminent. An example is shown in the figure. As shown in Figure 3, Cυ is a corona needle electrode, and Cυ is a microammeter with a zero scale in the center.
3) Ground electrode. (4) Meter relay. (5) Positive current contact (hereinafter referred to as a), (6) Negative current contact (hereinafter referred to as A), (7) Relay with holding circuit C return time of about 0.1 to 0.5 seconds. (8) Same as above. .

(9) A relay that operates when a and b operate simultaneously;
(10) This is an emergency signal approaching the W drop point.

That is. When thunderclouds approach. The negative corona current corresponding to the negative charge at the cloud base increases, but if lightning strikes from that cloud.

For the reason mentioned above, the polarity of the corona current suddenly reverses.

A significant amount of positive corona current flows out. As time passes, the negative charge at the cloud base increases. The current value of the microammeter decreases. It passes through zero and returns to the value before the lightning strike. If the meter pointer is a or b (if the polarity of the cloud is 10), it will be considered as a warning, and if a and b are activated at the same time, it will be an emergency warning. Riakayo K (go I)
perform one action.

B. The alarm will activate and issue an alarm (in the case of an alarm, it can also be reset by a manual switch).

The predicted electrical signals are sent to relays and used for various automatic controls such as opening and closing circuit breakers.

In addition, the method of measuring corona current is not limited to using an ammeter. An electronic circuit used in digital meters etc. may also be used.

It is also possible to carry out the same method using a rotating electric field strength measuring device instead of the corona needle electrode. According to the lightning point approach detection method of the present invention, a simple phenomenon of a sudden reversal of the electric field on the ground surface is used.

The approach of lightning is difficult to detect with the human five senses. Because it can be detected accurately. When used for protection against light electrical appliances. Do not turn off the power supply or signal circuit too early. This is a really useful invention because it allows you to cut off power circuits, etc. just before a lightning strike is expected, without cutting them off until the last minute.

[Brief explanation of drawings]

Figure 1. Cloud base and ground surface potential of a thundercloud. A diagram showing the relationship between space charges and the like using lines of electric force. Figure 2: A diagram showing how the thing in Figure 1 changes due to a lightning strike (thick arrow), also using electric lines of force. FIG. 3 is a wiring diagram for each block showing an embodiment of the lightning strike point approach detection method according to the present invention.

Claims (1)

[Claims] By detecting sudden changes in the ground electric field. A lightning point approach detection method that warns or signals that a lightning point is approaching.