CN117674053A - Ground potential counterattack protection circuit, method, device and system - Google Patents

Abstract

The invention discloses a ground potential counterattack protection circuit, a ground potential counterattack protection method, a ground potential counterattack protection device and a ground potential counterattack protection system. In the protection circuit, a first interface and a third interface are connected through a wire to form a first release passage; the first interface, the first delay inductor, the shunt, the third delay inductor and the third interface are electrically connected in sequence to form a second discharging passage; the first interface, the first delay inductor, the second delay inductor, the boost resistor and the second interface are sequentially and electrically connected to form a third discharge passage. When the circuit is applied to ground potential counterattack protection, a discharging path taking the third interface as a current discharging interface is formed, current is firstly discharged through an additional grounding electrode connected with the third interface, and the current discharging of a grounding grid connected with the second interface is reduced, so that the damage of ground potential counterattack on equipment and buildings is reduced through the reduction of the ground potential counterattack level of the grounding grid under the condition that the grounding grid and adjacent equipment are difficult to keep a minimum safe distance.

Description

Ground potential counterattack protection circuit, method, device and system

Technical Field

The present invention relates to the field of circuit protection technologies, and in particular, to a ground potential counterattack protection circuit, method, device, and system.

Background

When the building is struck by lightning, overvoltage far greater than withstand voltage of electronic equipment is generated, and if the grounding system is unreasonably designed or aged, equipment such as an information network system in the building can be damaged. If lightning protection ground potential countermeasures are not taken between lightning protection grounding systems of adjacent buildings, the countermeasures not only damage electrical equipment, but also can cause human injury or fire explosion accidents.

Ground potential counterattack generally refers to: when external lightning protection systems (such as lightning rods, lightning protection nets and the like) of a building are subjected to direct lightning strike, dangerous overvoltage is generated at two ends of a grounding resistor, and the overvoltage is introduced into the equipment by a grounding wire of the equipment, the external lightning protection systems of the building or other nearby buildings or other natural lightning receiving objects (various pipelines, cable shielding pipes and the like), so that the equipment is damaged.

The ground potential impact is generally in two forms: A. when lightning current flows into the ground, a larger voltage drop is generated due to the existence of a grounding resistor, so that the ground potential is raised, and the equipment is broken down reversely; B. and because the two grounding grids do not leave a sufficient safety distance, one grounding grid receives lightning current and generates high potential, the grounding grid which does not receive lightning stroke generates counterattack, and dangerous voltage is carried on the grounding system. When a building is directly struck by lightning, lightning current enters the ground along each down-lead and the grounding body in the lightning protection system of the building, in the process, the lightning current generates transient high voltage in the lightning protection system, if the insulation distance between the down-lead and surrounding network equipment is insufficient, and the PE line of the power supply system of the equipment is grounded and the logic ground of the signal system is not commonly grounded with the lightning protection system, very high voltage can occur between the PE line and the logic ground of the signal system of the equipment, discharge breakdown can occur, and serious damage to the equipment and even personal safety are caused. This counterattack of the ground potential caused by mishandling of the grounding technique causes the entire network system equipment to be destroyed. The transient high potential of the ground potential not only endangers equipment within the building, but also equipment within neighboring buildings. The equipment in the adjacent building is not struck by direct lightning, but after the nearby building is struck by lightning, transient high potential will be transferred along the underground pipeline to the lines in the equipment grounding system in the adjacent building to impact, so that the equipment connected with the lines is damaged by the transient high potential. The ground potential impact can induce impact voltage of several KV to tens of KV to hundreds of KV, and the impact can be transmitted into a room or spread to a larger indoor range in a wave form along a zero line of a power system to protect a grounding wire and the grounding wires in various forms, so that large-area harm is caused.

In order to prevent lightning current from striking against nearby metal objects or lines by high potential generated when the lightning current flows through the down conductor and the grounding device, the related electrical equipment needs to be erected outside a certain minimum safety distance so as to prevent the damage of the related electrical equipment connected with the grounding device caused by the ground potential striking.

Disclosure of Invention

The inventors have found that when lightning current is introduced into the ground system via the down conductor to generate a high ground potential, without sufficient isolation of the safety distance, the counterattack of the ground potential easily damages the electrical and electronic devices connected to the ground system, but for most electrical and electronic systems, the ground wire and the ground system are commonly connected together, and it is difficult to meet the requirement of setting the relevant electronic devices outside the minimum safety distance of the ground system, i.e. to prevent the counterattack of the ground potential over the safety distance.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a ground potential impact protection circuit, apparatus, method and system that overcomes or at least partially solves the above problems.

In a first aspect, an embodiment of the present invention provides a ground potential counterattack protection circuit, which is characterized by comprising: the device comprises a first interface, a second interface, a third interface, a first delay inductor, a second delay inductor, a third delay inductor, a boosting resistor and a shunt;

the first interface and the third interface are connected through a wire to form a first discharging passage;

the first interface, the first delay inductor, the shunt, the third delay inductor and the third interface are electrically connected in sequence to form a second discharging passage;

the first interface, the first delay inductor, the second delay inductor, the boost resistor and the second interface are sequentially and electrically connected to form a third discharge passage.

In some alternative embodiments, the first delay inductance has an inductance that is less than an inductance of the third delay inductance and the second delay inductance has an inductance that is greater than an inductance of the third delay inductance.

In some alternative embodiments, the first voltage drop generated by the current passing through the third delay inductance is greater than the second voltage drop generated by the first delay inductance, and the difference between the first voltage drop and the second voltage drop is greater than the starting voltage value of the shunt.

In some alternative embodiments, the boost resistor has a resistance value of not less than 30 ohms.

In some alternative embodiments, the flow capacity of the flow splitter is 50KA-100KA.

In a second aspect, an embodiment of the present invention provides a ground potential counterattack protection device, which is characterized by including: a housing and the protection circuit arranged in the housing;

the first interface, the second interface and the third interface are arranged on the shell; or alternatively, the first and second heat exchangers may be,

the shell is provided with a wire passing through hole, and the first interface, the second interface and the third interface are arranged outside the shell through wires passing through the wire passing through hole; or alternatively, the first and second heat exchangers may be,

the first interface, the second interface and the third interface are arranged inside the shell of the protection device, and a wire passing through hole is reserved on the shell.

In a third aspect, an embodiment of the present invention provides a ground potential counterattack protection system, including: the ground potential counterattack protection device comprises a lightning rod, a down conductor, a grounding grid, an additional grounding electrode and the ground potential counterattack protection device;

the lightning receiving rod, the down conductor and the grounding grid are connected in sequence;

the ground potential impact protection device is arranged at the disconnection card of the down conductor;

the additional grounding electrode is connected with the ground potential impact protection device through a grounding wire.

In some alternative embodiments, the first interface of the ground potential impact protection device is electrically connected with the upper interface of the down conductor break-off card, and the second interface is electrically connected with the lower interface of the down conductor break-off card;

the additional grounding electrode is connected with the third interface of the lightning stroke ground potential counterattack protection device through a grounding wire.

In some alternative embodiments, the distance between the down conductor and the additional ground line is not less than 3m.

In a fourth aspect, an embodiment of the present invention provides a ground potential counterattack protection method, implemented using the ground potential counterattack protection circuit, including:

after the current is introduced into the flash receiving rod, the current is introduced into a first interface of the ground potential counterattack protection circuit through the down lead, and is discharged for the first time through a first discharging passage, and the first delay inductor and the third delay inductor are charged;

after the first delay inductor and the third delay inductor are conducted, the current is discharged for the second time through a second discharging passage, and the second delay inductor is charged;

after the second delay inductor is conducted, the current is discharged for the third time through the second discharging passage and the third discharging passage.

In some alternative embodiments, the first and second current bleeds bleed current to ground through the additional ground electrode and the third bleeds bleed current to ground through the ground grid and the additional ground electrode.

The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:

according to the ground potential protection circuit provided by the embodiment of the invention, the first interface and the third interface are connected through the lead to form a first release passage; the first interface, the first delay inductor, the shunt, the third delay inductor and the third interface are electrically connected in sequence to form a second discharging passage; the first interface, the first delay inductor, the second delay inductor, the boost resistor and the second interface are sequentially and electrically connected to form a third discharge passage. When current flows into the first interface, the current is firstly discharged through the first discharging passage, and the first delay inductor and the third delay inductor are charged; after the first delay inductor and the third delay inductor are conducted, the current is discharged for the second time through the second discharging passage, and the second delay inductor is charged; and after the second delay inductor is conducted, current is discharged through the second discharging passage and the third discharging passage, and when current passes through the circuit, a discharging path taking the third interface as a current discharging interface is formed. When the circuit is applied to a ground potential counterattack protection system, a current discharge mode of using an additional grounding electrode as a first current discharge path is formed, so that the current flowing through the grounding grid is greatly reduced, the ground potential on the grounding grid is reduced, and under the condition that the grounding grid and adjacent equipment are difficult to keep a minimum safety distance, the electric and electronic systems connected with the grounding grid are protected through the descending of the ground potential counterattack level, and the damage of the ground potential counterattack to the electric and electronic systems is reduced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

The technical scheme of the invention is further described in detail through the drawings and the embodiments.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

FIG. 1 is a schematic diagram of a ground potential counterattack protection circuit in an embodiment of the invention;

FIG. 2 is a schematic diagram of a ground potential impact protection system according to an embodiment of the present invention;

fig. 3 is a schematic structural connection diagram of a ground potential impact protection system according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In order to solve the problems existing in the prior art, the embodiment of the invention provides a ground potential impact protection circuit, a device, a system and a method, wherein when current is discharged to a grounding device through a lead-down line after a current is introduced into a lightning rod, the embodiment of the invention utilizes the circuit design in the ground potential impact protection device to form the ground potential impact protection system with an additional grounding electrode as a discharging path, thereby weakening the current injected into a grounding grid, reducing the ground potential level of the grounding grid, and realizing the protection of an electric and electronic system connected with the grounding grid through the reduction of the ground potential impact level under the condition that the distance between the grounding grid and an adjacent electric and electronic system cannot meet the minimum safe distance.

As shown in fig. 1, an embodiment of the present invention provides a ground potential counterattack protection circuit, including: the first interface P1, the second interface P2, the third interface P3, the first delay inductor L1, the second delay inductor L2, the third delay inductor L3, the boosting resistor R and the shunt G;

the first interface P1 and the third interface P3 are connected through a wire to form a first discharging passage;

the first interface P1, the first delay inductor L1, the shunt G, the third delay inductor L3 and the third interface P3 are sequentially and electrically connected to form a second discharging passage;

the first interface P1, the first delay inductor L1, the second delay inductor L2, the boost resistor R and the second interface P2 are sequentially and electrically connected to form a third discharging passage.

As shown in fig. 1, in the protection circuit, the end a of the first delay inductor L1 is connected to the first interface P1, the end C is connected to the second delay inductor L2 and the shunt G, the other end of the second delay inductor L2 is connected to one end of the boost resistor R, and the other end of the boost resistor R is connected to the second interface P2; the D end of the shunt G is connected with one end of a third delay inductor L3, and the B end of the third delay inductor L3 is connected with a third interface P3.

In the ground potential counterattack protection circuit, the inductance of a first delay inductor L1 is smaller than that of a third delay inductor L3, and the inductance of a second delay inductor L2 is larger than that of the third delay inductor L3; the first voltage drop generated by the current passing through the third delay inductance L3 is larger than the second voltage drop generated by the first delay inductance L1, and the difference value between the first voltage drop and the second voltage drop is larger than the starting voltage value of the shunt G.

Optionally, a current divider G is used in the protection circuit, and since the current divider G has a starting voltage, the current isolation and conduction functions can be realized through the switching effect of the current divider G. In the schematic diagram of the protection circuit shown in fig. 1, when the point C is at a low potential, the shunt G is in an open state, i.e. the current is discharged by the first discharging path, and when the point C is at a high potential, and the voltage difference between the point C and the point D reaches the starting voltage value of the shunt G, the shunt G is in a short-circuit state, i.e. the current can be discharged by the second discharging path. The current capacity of the shunt G may be selected from 50KA to 100KA, and the specific current capacity value of the shunt may be selected in combination with local lightning activity characteristics, and may be selected according to the B-stage protection current capacity reference in GB50057-2010, which is not limited in this invention.

In the embodiment of the present invention, the inductance value relationship between the first delay inductance L1 and the third delay inductance L3 of the ground potential impact protection circuit can be calculated according to the conduction condition of the shunt G and the magnitude of lightning current, for example, as follows:

the lightning current is 100kA under the waveform of 10/350us, and the starting voltage of the shunt G is 1200V, namely U _CD ≥1200V；

The differential relation between the inductance voltage and the current is utilized to obtain:

U _BD ＝L3*di/dt

U _AC ＝L1*di/dt

since the first voltage drop generated by the current passing through the third delay inductance L3 is larger than the second voltage drop generated by the first delay inductance L1, and the difference between the first voltage drop and the second voltage drop is larger than the starting voltage value of the shunt G, the shunt G can be conducted,

i.e. L3di/dt-L1di/dt.gtoreq.1200V, di/dt=100 kA/10us=10 ¹⁰ ，

The method can obtain: L3-L1 is more than or equal to 0.12uH;

let the lightning current be 10kA at a waveform of 10/350us, when the starting voltage of the shunt G is 1200V,

then L3.di/dt-L1.di/dt.gtoreq.1200V, di/dt=10kA/10us=10 ⁹ ，

The L3-L1 is more than or equal to 01.2uH;

therefore, the specific inductance of the first delay inductor L1 and the third delay inductor L3 is designed to satisfy that the voltage drop generated by the current passing through the third delay inductor L3 is larger than the voltage drop generated by the first delay inductor L1 under the current passing condition, and the difference value of the voltage drops is not smaller than the starting voltage of the shunt G, that is, the specific inductance of the first delay inductor L1 and the third delay inductor L3 can be selected by itself under the condition that the numerical relation of the first delay inductor L1 and the third delay inductor L3 is satisfied.

Optionally, the inductance of the second delay inductance L2 is selected to meet the time constant of the ground network greater than the additional ground time constant,

namely: l2/(boost resistor R+ground network ground resistor) > L3/additional ground resistance;

because the additional grounding electrode is used as a leakage path in the protection circuit, the sum of the resistance value of the boosting resistor R and the grounding resistance of the grounding network is required to be larger than the resistance value of the additional grounding electrode so as to enable the current to be discharged through the third interface P3; optionally, the resistance value of the boost resistor R is not less than 30 ohms, and the specific value of the boost resistor R can be selected by self under the condition that the sum of the resistance value of the boost resistor R and the grounding resistance of the grounding network is larger than the additional grounding electrode resistance value; therefore, in the protection circuit, the inductance of the second delay inductor L2 should be greater than the inductance of the third delay inductor L3, and the second delay inductor L2 is set to play a secondary buffering role on the third discharging channel, so that the current is preferentially discharged to the second discharging channel by using the current, and the current is led into the ground through the P3 interface.

Based on the same inventive concept, an embodiment of the present invention provides a ground potential counterattack protection device, which is characterized by comprising: the shell and the ground potential impact protection circuit are arranged in the shell;

the first interface P1, the second interface P2 and the third interface P3 of the ground potential counterattack protection circuit are arranged on the shell of the protection device; or the shell is provided with a wire passing through hole, and the first interface P1, the second interface P2 and the third interface P3 are arranged outside the shell through wires passing through the wire passing through hole; or the first interface P1, the second interface P2 and the third interface P3 are arranged inside the shell of the protection device, a wire passing through hole is reserved on the shell, and when the protection device is connected with other components, a connecting wire can pass through the wire passing through hole to be connected with the first interface P1, the second interface P2 and the third interface P3.

As shown in fig. 2-3, an embodiment of the present invention further provides a ground potential counterattack protection system, including: the ground potential impact protection device comprises a lightning rod, a down conductor, a grounding grid, an additional grounding electrode and the ground potential impact protection device provided by the embodiment of the invention;

wherein the lightning rod, the down conductor and the grounding grid are connected in sequence; the ground potential impact protection device is arranged at the disconnection card of the down conductor; the additional grounding electrode is connected with the ground potential impact protection device through a grounding wire.

In the ground potential impact protection system, a first interface P1 of a ground potential impact protection device is electrically connected with an upper interface of a down conductor disconnection card, and a second interface P2 of the ground potential impact protection device is electrically connected with a lower interface of the down conductor disconnection card; the additional grounding electrode is connected with a third interface P3 of the lightning ground potential counterattack protection device through a grounding wire. Optionally, the ground potential impact protection device may also be disposed at the top lightning rod base flange.

As shown in fig. 3, the ground potential protection device requires the following requirements in connection with the protection system:

the distance D1 between the grounding grid and the additional grounding electrode is more than or equal to 3m; the additional grounding interelectrode distance D2 is more than or equal to 2L;

the buried depth of the additional grounding electrode is D3 is more than or equal to 0.5m; the length of the additional grounding electrode is L=1.5-2.5 m;

the distance between the down conductor and the additional ground line is not less than 3m, and may be, for example, 4m, 5m, 6m, 8m, 10m, … ….

Namely, in the setting process of all parts of the ground potential impact protection system, an additional grounding electrode needs to be additionally arranged at a distance of 3m from the down conductor, and the burying depth of the additional grounding electrode is not less than 0.5m. The length is between 1.5 and 2.5 m. For the number of the additional grounding poles, more than 1 additional grounding pole can be selected to be buried according to the resistance value of the grounding pole for current discharge; and the voltage of the ground potential depends on the resistance value of the grounding resistor, so that under the condition that the boosting resistor is arranged in the protection circuit, the sum of the grounding resistor of the grounding network and the boosting resistor is ensured to be larger than the resistance value of the auxiliary grounding electrode, and when current passes through the protection circuit, the current is preferentially discharged through the auxiliary grounding electrode under the better discharging condition of the additional grounding electrode. Namely, the ground resistance of the additional grounding electrode in the ground potential impact protection system is not forced, and the additional grounding resistance is selected to be smaller as much as possible, for example, less than 10 ohms under the condition that the current discharge capability is met.

The embodiment of the invention also provides a ground potential impact protection method which can be realized by using the ground potential impact protection circuit of the embodiment of the invention, and comprises the following steps:

after the current is introduced into the flash receiving rod, the current is introduced into a first interface P1 of the ground potential counterattack protection circuit through the down lead, and is discharged for the first time through a first discharging passage, and a first delay inductor L1 and a third delay inductor L3 are charged;

after the first delay inductor L1 and the third delay inductor L3 are conducted, current is discharged for the second time through a second discharging passage, and the second delay inductor L2 is charged;

after the second delay inductor L2 is conducted, the current is discharged for the third time through the second discharging passage and the third discharging passage.

According to the method, lightning current is discharged to the ground through the additional grounding electrode for the first time and the second time, and is discharged to the ground through the grounding network and the additional grounding electrode for the third time, after multiple times of discharging, voltage and current are reduced to a great extent when passing through the grounding network, and damage to electronic components is effectively avoided.

As shown in fig. 1, the working principle of the ground potential impact protection method implemented by using the ground potential impact protection circuit according to the embodiment of the present invention is as follows:

that is, when the lightning rod is struck by lightning, the lightning current leaks down by the down conductor and enters the first interface P1, due to the delay and choke effect of the first delay inductor L1 and the third delay inductor L3 on the instantaneous current, the current is discharged through the first discharging path at the moment that the lightning current enters the first interface P1, the lightning current is led into the ground through the additional grounding electrode connected with the third interface P3, and does not enter the main channel of the down conductor consisting of the boost resistor R and the second delay inductor L2, and in the process of discharging the current through the first discharging path, the first delay inductor L1 and the third delay inductor L3 are in a charging state.

After the transient lightning impulse, the high voltage across A, B on the first and third delay inductors L1 and L3 will push their currents to conduct. When the inductance of the first delay inductor L1 is smaller than that of the third delay inductor L3, the voltage drop across the first delay inductor L1 will be smaller than that across the third delay inductor L3, i.e. U _C >U _D In order to ensure that the high-voltage driving shunt G at the point C is conducted at the moment, the difference value between the voltage drop on the first delay inductance L1 and the voltage drop on the third delay inductance L3 is not smaller than the driving voltage value of the shunt G; at this time, the lightning current is discharged through the second discharging channel and is led into the ground through the additional grounding electrode, so that the second lightning current discharging is completed, and the second delay inductor L2 is in a charging state in the process.

Along with the conduction of the second delay inductor L2, the third bleeder path is in a conduction state, and due to the existence of the boost resistor R, the sum of the resistance value of the boost resistor R and the grounding resistance of the grounding grid is larger than the resistance value of the additional grounding electrode, so that the point C is in a high potential, and at the moment, lightning current is subjected to third current bleeder through the second bleeder path and the third bleeder path.

Under the general condition, the ground potential counterattack voltage is up to several kilovolts and even tens of thousands of volts, so that the ground potential counterattack voltage has stronger damage capability to electronic and electric systems, particularly electronic systems; compared with the traditional lightning protection system, the embodiment of the invention is added with the ground potential counterattack protection device and introduces the additional grounding electrode connected with the ground potential counterattack protection device, under the action of the internal circuit of the protection device, lightning current firstly discharges current through the additional grounding electrode, so that the current injected into the grounding grid is weakened, the ground potential counterattack level of the grounding grid is further reduced, and the electric and electronic systems connected with the grounding grid are protected.

It should be understood that the specific order or hierarchy of steps in the processes disclosed are examples of exemplary approaches. Based on design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

In the foregoing detailed description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the subject matter require more features than are expressly recited in each claim. Rather, as the following claims reflect, invention lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate preferred embodiment of this invention.

The foregoing description includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims. Furthermore, as used in the specification or claims, the term "comprising" is intended to be inclusive in a manner similar to the term "comprising," as interpreted when employed as a transitional word in a claim. Furthermore, any use of the term "or" in the specification of the claims is intended to mean "non-exclusive or".

Claims (11)

1. A ground potential counterattack protection circuit, comprising: the device comprises a first interface, a second interface, a third interface, a first delay inductor, a second delay inductor, a third delay inductor, a boosting resistor and a shunt;

the first interface and the third interface are connected through a wire to form a first discharging passage;

the first interface, the first delay inductor, the shunt, the third delay inductor and the third interface are electrically connected in sequence to form a second discharging passage;

the first interface, the first delay inductor, the second delay inductor, the boost resistor and the second interface are sequentially and electrically connected to form a third discharge passage.

2. The circuit of claim 1, wherein an inductance of the first delay inductance is less than an inductance of the third delay inductance and an inductance of the second delay inductance is greater than an inductance of the third delay inductance.

3. The circuit of claim 2, wherein a first voltage drop across the third delay inductance is greater than a second voltage drop across the first delay inductance, and wherein a difference between the first voltage drop and the second voltage drop is greater than a start-up voltage value of the shunt.

4. The circuit of claim 1, wherein the boost resistor has a resistance value of not less than 30 ohms.

5. The circuit of any of claims 1-4, wherein the current divider has a current capacity of 50KA-100KA.

6. A ground potential counterattack protection device, comprising: a housing and a protection circuit according to any one of claims 1 to 5 disposed within the housing;

the first interface, the second interface and the third interface are arranged on the shell; or (b)

The shell is provided with a wire passing through hole, and the first interface, the second interface and the third interface are arranged outside the shell through wires passing through the wire passing through hole; or (b)

The first interface, the second interface and the third interface are arranged inside the shell of the protection device, and a wire passing through hole is reserved on the shell.

7. A ground potential counterattack protection system, comprising: a lightning rod, a down conductor, a grounding net, an additional grounding electrode and a ground potential impact protection device according to claim 6;

the lightning receiving rod, the down conductor and the grounding grid are connected in sequence;

the ground potential impact protection device is arranged at the disconnection card of the down conductor;

the additional grounding electrode is connected with the ground potential impact protection device through a grounding wire.

8. The system of claim 7, wherein the ground potential counterattack protection device first interface is electrically connected to the down conductor break card upper interface and the second interface is electrically connected to the down conductor break card lower interface;

the additional grounding electrode is connected with the third interface of the lightning stroke ground potential counterattack protection device through a grounding wire.

9. The system of claim 7, wherein the down conductor is not less than 3m from the additional ground line.

10. A ground potential counterattack protection method implemented using the ground potential counterattack protection circuit according to claims 1-5, comprising:

after the current is introduced into the flash receiving rod, the current is introduced into a first interface of the ground potential counterattack protection circuit through the down lead, and is discharged for the first time through a first discharging passage, and the first delay inductor and the third delay inductor are charged;

after the first delay inductor and the third delay inductor are conducted, the current is discharged for the second time through a second discharging passage, and the second delay inductor is charged;

after the second delay inductor is conducted, the current is discharged for the third time through the second discharging passage and the third discharging passage.

11. The method of claim 10, wherein the first and second current bleeds bleed current to ground through an additional ground electrode and the third bleed bleeds current to ground through a ground grid and an additional ground electrode.