RU2633364C2 - Lightning protection method on principle of screening protected object from lightning discharge and device for its implementation - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: physics of the invention is to generate a space charge above the protected object, which provides energy dissipation, which reduces the power of the lightning discharge, the equalization of the electric field above the protected object, which prevents the formation of a counter leader, which reduces the area of pulling lightning discharges to the protected zone. Under certain conditions, the charge can polarize, forming a field above the protected zone of a unipolar with a descending leader of lightning, creating a repulsive force that changes the direction of the leader's movement from the protected object. To screen the object from the descending leader of the lightning, conditions are ensured for maintaining the corona current below the critical value, above which the counter discharge switches to the streamer form. The task is achieved by a device consisting of a plurality of pins-ionizers. As a result, charge is formed over the protected area, unipolar to downward leader of the lightning discharge, the interaction of their fields generates a force, repulsive the lightning leader from the protected area. The present invention can further be implemented as a metal strip with rounded edges or metal wires, which are mounted on pins-ionizers. To align the field along the edges of the structure, the ionization electrodes are made with an inclination to the outside or the base edges are bent.

EFFECT: reducing thunderstorm activity in the protected area and levels of destructive effects on the object caused by nearby lightning discharges.

2 cl, 3 dwg

Description

The lightning protection method based on the principle of shielding the protected object from lightning discharge is based on preventing the occurrence of lightning discharge in the protected zone by generating a space charge over the protected object by coronation under the influence of an external cloud-to-ground electric field on a plurality of ionizing electrodes, due to which :

- energy dissipation, reducing the power of lightning discharge;

- alignment of the electric field over the protected object, which prevents the formation of an oncoming leader, which reduces the area of pulling lightning discharges to the protected zone;

- under certain conditions, the charge can be polarized, forming a field above the protected zone of a unipolar lightning with a downward leader, creating a repulsive force that changes the leader's direction of movement from the protected object.

Nowadays, an increasing number of microelectronic equipment used in buildings is damaged due to electromagnetic radiation produced by the lightning rod during the passage of lightning into the ground. Therefore, a lightning rod cannot protect modern high-tech equipment, and the use of new technologies to protect against lightning is extremely necessary.

Known devices for lightning protection used to protect ground objects, containing a rod lightning rod, a down conductor and concentrated ground electrodes, made in accordance with the recommendations of document SO-153-34.21.122.2003 [1]. The principle of their action is based on the provocation of MP in the elements of the Ministry of Health, which should ensure the safe spreading of the lightning current.

A known method of neutralizing the charges of a thundercloud is that a lightning tower with a laser and a mirror corner reflector is installed in the desired zone, a plasma plasma channel is created from the tower to the bottom of the thundercloud, multiple lightning discharges are carried out on the laser channel. The laser is turned on when reaching the pre-thunderstorm electrostatic field of the troposphere (RU 2004125693 A, publ. 02.10.2006).

A known method of protection against discharges of atmospheric electricity (lightning) by trapping and neutralizing, including the use of a grounded rod, which is placed vertically. In addition, an ionizing air source is used, the beam of which is directed along the grounded rod vertically into the upper layers of the atmosphere, thereby creating a conductive strip of ionized gases in the air, which serves as a conductor for the passage of lightning into the rod, where it is neutralized by grounding. A lightning discharge occurs at a lower electric field with less destructive effect (RU 2000125979 A, publ. 10.09.2002).

A known method of protection against atmospheric electrical overvoltages, based on the implementation of the forced discharge of a thunderstorm cell by exciting a stably developing leader of an electric spark discharge. The leader is excited by creating at least one chain of zones of electrodeless electric breakdown of air with overlapping shells of low-temperature plasma (RU 2144747 C1, publ. 01.20.2000).

A known method of lightning protection of buildings and structures using a lightning rod containing a dielectric housing with a transverse rib, in the cover of which is inserted a central rod-air terminal and side rods. The central ground rod is inserted into the base of the chassis. Capacitor plates connected to internal spark gap are placed in the housing. The cover is made conductive, side rods are inserted into it. Two chains of series-connected resistors are placed in the housing, the number of which and their values in each circuit are the same. The first findings of the resistors of the first circuit are connected to the upper plates of the capacitors.

The first findings of the resistors of the second circuit are connected to their lower plates. The arresters are located on adjacent plates of adjacent capacitors (RU 2208887 C1, publ. 20.07.2003).

A device for changing the space charge in the atmosphere, containing a corona electrode mounted on supports, according to the present invention, is provided with a conductor for communicating to the corona electrode from the lower layers of the earth's crust a high voltage static voltage relative to the volume electrostatic charge that has arisen in the atmosphere (RF patent No. 2144820).

The electric conductor for transmitting electrostatic voltage from the deep layers of the earth's crust to the corona electrode is made in the form of a borehole drilled in the earth's crust with metal casing installed in it, which are electrically connected to the corona electrode. The corona electrode in the proposed device is made in the form of a metal cable, the upper end of which is connected to a metal ring.

Also known is a device for creating a space charge in the atmosphere, containing one or more electrodes in the form of peaks connected to a source of high constant or pulsating voltage, and an aircraft jet engine. In this case, the electrodes are installed in the nozzle of the jet engine (ed. Certificate. No. 446955, H05F 3/00, 1973).

Common disadvantages of the above technical solutions is a significant increase in the number of discharges in the field of protected objects due to the provocation of lightning discharges.

As a result:

- the probability of lightning discharges to the lightning protection system increases, which, in turn, leads to an increased risk of lightning breaking through this system;

- the levels of electromagnetic effects on the equipment of the protected object are increased due to the pulling of lightning discharges to the protected zone, which necessitates increasing the level of protection of objects from secondary manifestations of lightning discharges (potential drift, exposure to electric and magnetic fields).

In 1995, the author of the invention (Chinese patent CN 1049531 C) described a completely new technology of protection against lightning, which avoids a direct lightning strike into a protected object. This technology can be applied not only to stationary objects located on the ground, but also to moving objects located on the ground, sky and in the air to protect them from lightning. For an object located on the ground, protection is as follows: an artificial plasma ball is proposed that causes the disappearance of induced charges on the protected object, as well as preventing induced charges on such an object, by transferring charges of opposite polarity, relative to the induced charges, to the protected object.

The disadvantage of this technical solution is the complexity and energy consumption in the implementation.

The closest in technical essence to the present invention is a device for creating a space charge in the atmosphere, containing an electrode made in the form of a vertical column having at its upper end one or more peaks connected to a source of high constant or pulsating voltage (RF patent No. 2034315, IPC: G01W 1/00, 1991) This device is designed to act on clouds to change their electrical activity or sediment-forming ability by artificially introducing into clouds uncompensated electric charge.

Also close in technical essence to the present invention is a device made in the form of a wire mounted on supports above the surface of the earth and connected to a voltage source capable of providing on the wire a potential of one sign relative to the potential of the Earth, at least equal to the critical voltage at which around a corona discharge occurs (RF patent No. 2060639, IPC: G01W 1/00, 1991). The wire has a length of 6-7 km and to cover the largest possible area stretched in a straight line, or has one turn of 90 °, or extended in the shape of the letter T.

The disadvantages of the described devices are the need for an energy source, as well as a weak electric field created by the injected space charge in the atmosphere due to the location of the corona wire in a straight line over long distances. As a result of this, electric forces practically do not participate in the transfer of ions from the device to the clouds, and the efficiency of the device is therefore low when exposed to clouds, especially layered clouds. The weakness of the charge density and electric field in the atmosphere in the vicinity of the device is a consequence of the suspension of the corona wire in a straight line over long distances, as a result of which the charge is distributed in air over a large area. As a result, when a layered cloud is exposed, under which ascending flows are weak, the ions generated in the air by the device have little chance of getting into the cloud layer.

The basis of the invention is the task of developing a method of shielding the protected object from downward lightning discharges, which will reduce lightning activity in the protected area and the levels of destructive effects on the object caused by close lightning discharges [2]. The physics of the invention consists in generating a space charge over the protected object.

The operation of the device is illustrated in FIG. 1. To shield object 1 from the descending lightning leader, the conditions for maintaining the corona current below a critical value are provided, above which the oncoming discharge undergoes a streamer form. The problem is achieved by a device consisting of many pin-ionizers 2. An increase in the electric field due to the action of a thundercloud and an approaching lightning leader causes a corona discharge from the vertices of the ionizer electrodes.

The corona current of the system is determined by the expression

where J is the current density

ε is the electric constant;

t is time.

As a result of this, an uncompensated volumetric electric charge is created in the atmosphere in the immediate vicinity of the points. The corona charge of the system is determined by the expression

Where q is the charge;

ε is the electric constant;

E ₀ - the electric field strength of the cloud-ground;

E _0cor is the electric field strength of the corona;

t is time.

An increase in the number of electrodes leads to a decrease in the corona current from each of them with an external field approaching the threshold value of the electric field strength of the corona formation. With a sufficiently large number of electrodes, the corona current of each of them remains negligible both in the field of a thundercloud and when it is amplified by the charge of a close downward lightning, which prevents the oncoming leader from being protected. An extensive flat cloud of a corona discharge above the electrode system shields the electric field of the atmosphere at its location, which leads to a decrease in the radius of attraction of lightning and, accordingly, the number of discharges into the protected object.

Further, ions of different signs move towards each other. At the upper boundary, under the influence of an external electric field generated by a thundercloud, partial recombination of ions occurs. As a result, charge 3 is formed above the protected zone, a unipolar descending leader of the lightning discharge, the interaction of their fields forms a force that repels the lightning leader from the protected zone.

The present invention can further be implemented in the form of a metal strip (sheet) 4 with rounded edges (Fig. 2) or in the form of a metal wire on which the ionizer pins 2 are fixed.

To align the field at the edges of the structure, the ionizing electrodes are performed with an inclination to the outside or bend the edges of the base.

For efficient operation, the device must be equipped with effective grounding and potential equalization systems with grounding of the protected object. With grounding, the device is combined via a down conductor 5.

For large objects, it is efficient to implement the device according to the embodiment of FIG. 3 in the form of a metal wire 1 stretched over the protected zone with ionizers 2 mounted on it with pins (like a barbed wire).

Technical results are achieved by the fact that, in contrast to the known principles of lightning protection, which provoke lightning discharges into lightning protection elements (therefore, increasing lightning activity), this invention prevents the occurrence of lightning discharge conditions, which reduces the levels of destructive effects on objects from close lightning discharges.

The use of such systems is most effective for objects located in the northern regions, where due to the small number of metal-intensive objects when using traditional lightning protection systems (provoking the development of lightning discharges), a significant increase in the density and power of lightning discharges over the protected object is observed, which ultimately leads to to increase the risk of damage to equipment and personnel injuries as a result of a lightning breakthrough through the lightning protection system.

Information sources

1. SO-153-34.21.122.2003 "Instructions for the lightning protection device of buildings, structures and industrial communications." MEI Publishing House, M., 2004.

2. Ermakov K.V., Ryabov Yu.G. “The concept of potential lightning protection of facilities and equipment. New Approaches and Collateral Principles (Part I). ” “EMC Technologies”. No. 4, 2010.

Claims (2)

1. The method of lightning protection on the principle of shielding the protected object from lightning discharge, characterized in that it prevents the conditions for lightning discharge by generating a space charge over the protected object by coronation under the influence of an external cloud-to-ground electric field on a plurality of ionizing electrodes, which reduces levels of destructive effects on objects from lightning discharges. 2. A device for implementing the method according to claim 1, comprising a base consisting of a metal strip with rounded edges or a metal wire on which pins-ionizers are mounted obliquely, the edges of the base being bent to equalize the electric field and grounding the base via a down conductor connected to it .

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