Protection method, circuit and pulsed electronic device against back strike of a pulsed source discharge

Abstract

The application relates to a protection method, circuit and pulse electronic device for discharge back strike of a pulse source. The method comprises the following steps: obtaining a first back strike current formed by external discharge of the pulse source; increasing the number of accessed unit-level sub-circuits to perform pulse amplitude reduction on the first back strike current through the accessed unit-level sub-circuits, so as to obtain a second back strike current after pulse amplitude reduction; and returning the second back strike current to the pulse source. The method can distribute or disperse the first back strike current generated by the pulse source in the discharge process through the way of accessing the unit-level circuit in the discharge circuit, reduce the amplitude of the back strike pulse returned to the pulse source, eliminate the energy of the back strike current, achieve the effect of discharging back strike protection of the pulse source, meet the impedance requirement in different scenes, realize good discharge back strike protection of the pulse source, and have good adaptability. The scheme can be widely applied to the technical field of power system protection.

Description

Technical Field

[0001] This application relates to the field of power system protection technology, and in particular to a protection method, circuit, and pulse electronic device for pulse source discharge return stroke. Background Technology

[0002] In experiments and related applications of electromagnetic pulse interaction effects at the electronic device level, high-power pulse sources typically require a discharge circuit to ground via a microstrip antenna and a matching resistor. During discharge, because the matching resistor is directly grounded, a large first backflash current is generated. This pulse current is reflected back to the pulse source along the matching resistor and microstrip antenna, forming a transient high-voltage pulse. This pulse then conducts interference through the various connection lines of the pulse source, affecting its normal operation and even damaging its core components. Therefore, effective protection against backflash current is essential for improving the reliability of pulse source operation.

[0003] Traditional technologies have proposed using impedance matching for backflash protection, which involves adjusting the load impedance to match the ground resistance to eliminate current backflash; or strengthening the circuit system of the pulse source, for example, by adding discharge tubes or special geometric designs at the nodes of critical circuits.

[0004] However, the impedance matching protection method requires adjusting the impedance of the load, which makes it unsuitable for application scenarios where impedance requirements are constantly changing, resulting in poor adaptability. Summary of the Invention

[0005] Therefore, it is necessary to provide a well-adaptable protection method for pulse source discharge backflash, as well as a corresponding protection circuit and device, to address the above-mentioned technical problems.

[0006] Firstly, this application provides a method for protecting against pulse source discharge return stroke. The method includes:

[0007] Obtain the first return stroke current formed by the external discharge of the pulse source;

[0008] Increase the number of connected unit-level sub-circuits to reduce the pulse amplitude of the first return stroke current through the connected unit-level sub-circuits, and obtain the second return stroke current after pulse amplitude reduction;

[0009] The second return current is fed back to the pulse source.

[0010] In one embodiment, acquiring the first return current formed by the external discharge of the pulse source includes:

[0011] Obtain the reflected current and refracted current generated by the pulse source's external discharge;

[0012] The reflected current and the refracted current are added together to form the first return stroke current.

[0013] In one embodiment, acquiring the reflected current and refracted current generated by the pulse source's external discharge includes:

[0014] Obtain the incident voltage for external discharge;

[0015] The refracted voltage is determined by multiplying the refractive index of the external discharge path with the incident voltage; the reflected voltage is determined by multiplying the reflection index of the external discharge path with the incident voltage.

[0016] The refracted current is generated based on the refracted voltage and the first equivalent impedance of the external discharge path; the reflected current is generated based on the reflected voltage and the first equivalent impedance of the external discharge path.

[0017] In one embodiment, increasing the number of connected unit-level sub-circuits to reduce the pulse amplitude of the first return stroke current through the connected unit-level sub-circuits to obtain a second return stroke current with reduced pulse amplitude includes:

[0018] Obtain the second equivalent impedance of the accessed unit-level sub-circuit;

[0019] The pulse amplitude of the voltage value corresponding to the return current is reduced based on the second equivalent impedance.

[0020] In one embodiment, the voltage value corresponding to the return stroke current after pulse amplitude reduction satisfies the following calculation formula:

[0021]

[0022] Among them, U bb U0 is the voltage value after pulse amplitude reduction, Z is the voltage value before pulse amplitude reduction, I is the impedance value of the second equivalent impedance, and n is the current value of the return stroke current.

[0023] Secondly, this application also provides a protection circuit for pulse source discharge return stroke. It includes a ground discharge module and a return stroke attenuation module:

[0024] The grounding discharge module collects the external discharge from the external pulse source to generate a return stroke current, and outputs the return stroke current to the return stroke attenuation module; the return stroke attenuation module reduces the pulse amplitude of the return stroke current by adjusting the number of conducting sub-circuits of the built-in unit level, and sends the pulse amplitude-reduced return stroke current to the external pulse source.

[0025] In one embodiment, the grounding discharge module includes a microstrip antenna and a grounding resistor, and the return stroke current includes reflected current and refracted current;

[0026] The microstrip antenna is connected to an external pulse source through the return stroke attenuation module, and the grounding resistor is connected to the external pulse source through the return stroke attenuation module.

[0027] The microstrip antenna generates reflected current and refracted current during electromagnetic pulse radiation; the grounding resistor generates reflected current and refracted current during grounding discharge.

[0028] In one embodiment, the unit-level sub-circuit includes several ground protection sub-circuits connected in parallel;

[0029] One end of the grounding protection sub-circuit is grounded, and the other end of the grounding protection sub-circuit is connected to the external pulse source.

[0030] In one embodiment, the return stroke attenuation module further includes a ground bus, and one end of the ground protection sub-circuit is grounded through the ground bus;

[0031] Alternatively, the return stroke attenuation module may further include a metal braid, and one end of the grounding protection sub-circuit may be grounded through the metal braid.

[0032] Thirdly, this application also provides a pulse electronic device, which includes a pulse source and the protection circuit described in the second aspect, wherein the pulse source is connected to the ground discharge module and the return stroke attenuation module in the protection circuit.

[0033] The aforementioned pulse source discharge backstroke protection method, protection circuit, and pulse electronic device, by connecting unit-level circuits in the discharge circuit, distribute or disperse the first backstroke current generated by the pulse source during the discharge process, thereby reducing the amplitude of the backstroke pulse returning to the pulse source and eliminating the energy of the backstroke current, thus achieving the effect of pulse source discharge backstroke protection. The solution of this application can adjust the equivalent impedance in the discharge circuit by changing the number of unit-level circuits connected to the discharge circuit, which can meet the impedance requirements in different scenarios, achieve good pulse source discharge backstroke protection, and has good adaptability. Attached Figure Description

[0034] Figure 1 This is an application environment diagram of a pulse source discharge return stroke protection method in one embodiment;

[0035] Figure 2 This is a flowchart illustrating a method for protecting against pulse source discharge return stroke in one embodiment;

[0036] Figure 3 This is a schematic diagram of a pulse source-to-ground discharge circuit in one embodiment;

[0037] Figure 4 This is a schematic diagram of a return current intrusion pulse source circuit in one embodiment;

[0038] Figure 5 This is a schematic diagram of the process for obtaining the first return stroke current in one embodiment;

[0039] Figure 6 This is a schematic diagram of the waveforms of the reflected voltage and the refracted voltage during the discharge process in one embodiment.

[0040] Figure 7 This is a schematic diagram of the waveforms of the reflected current and the refracted current during the discharge process in one embodiment;

[0041] Figure 8 This is a wiring diagram of an overhead line in one embodiment;

[0042] Figure 9 for Figure 8 A schematic diagram of the equivalent circuit of the overcurrent circuit;

[0043] Figure 10 This is a schematic diagram of a protection circuit for pulse source discharge return stroke in one embodiment;

[0044] Figure 11 This is a schematic diagram of the grounding protection sub-circuit in one embodiment;

[0045] Figure 12 This is a schematic diagram of a multi-point grounding connection line in one embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0049] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0050] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0051] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0052] When used herein, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0053] The protection method for pulse source discharge return stroke provided in this application embodiment can be applied to, for example, Figure 1 In the application environment shown, the pulse source 102 is connected to the protection circuit 104. The pulse source 102 can be grounded through the protection circuit 104. During the grounding discharge process, a large first return current may be generated. When the return current returns to the protection circuit 104, several unit-level sub-circuits are pre-connected in the protection circuit 104. By connecting the unit-level sub-circuits, the pulse amplitude of the returned return current is reduced to eliminate the pulse energy. The reduced second return current is then returned to the pulse source. Since the amplitude and energy of the second return current are attenuated and eliminated compared to the first return current, the damage to the pulse source is effectively reduced.

[0054] In one embodiment, such as Figure 2 As shown, a protection method for pulse source discharge return stroke is provided, which is applied to... Figure 1 Taking the protection circuit 104 in the diagram as an example, the method mainly includes the following steps:

[0055] S202, Obtain the first return current formed by the external discharge of the pulse source;

[0056] The first return stroke current can refer to the large return pulse current generated when the external pulse source discharges due to the direct grounding of the matching resistor or impedance. This return pulse current can travel back to the pulse source along the discharge circuit, causing conducted interference to the discharge circuit and potentially affecting the normal operation of the pulse source. In this embodiment, the discharge circuit can refer to the high-power pulse source forming a discharge circuit to ground through the connection of the microstrip antenna and the matching resistor.

[0057] For example, in the implementation scenario of electromagnetic pulse interaction at the electronic device level, a high-power pulse source forms a discharge loop to ground through a matching resistor (grounding resistor). Since the point where the uniformity of the discharge loop begins to be disrupted can be called a node, and the traveling wave transmission process of the pulse source's external discharge can be equivalent to a traveling wave short-circuiting at the end of the line; the grounding point of the discharge loop can be considered as a node, and the electromagnetic pulse generated by the high-power pulse source during the discharge process can be regarded as a traveling wave. When the traveling wave is projected onto the node, a process of voltage, current, and energy readjustment and distribution will occur, that is, the traveling wave undergoes refraction and reflection at the node, thereby forming a return current.

[0058] S204. Increase the number of connected unit-level sub-circuits to reduce the pulse amplitude of the first return stroke current through the connected unit-level sub-circuits, and obtain the second return stroke current after pulse amplitude reduction.

[0059] The unit-level sub-circuit is a subset of circuits connected to the same grounding point as the pulse source. This subset circuit can contain other loads such as the pulse source, or it can be directly grounded. The main function of the unit-level sub-circuit is to distribute or disperse the first return stroke current, thereby reducing its amplitude. In this embodiment, the reduction process refers to pulse amplitude reduction of the return stroke current, achieving pulse energy elimination. Obviously, the second return stroke current refers to the current obtained after pulse energy elimination of the first return stroke current; this current will be directly transmitted back to the pulse source.

[0060] For example, such as Figure 3 The diagram shows a pulse source discharge circuit to ground. Figure 3 The arrows in the diagram indicate the direction of electromagnetic pulse or current transmission during discharge. Figure 3 Point G in the diagram is the grounding discharge point in the circuit, and the discharge channel impedance can be denoted as Z0. Figure 3 Circuits 1 to N in the diagram can be considered as individual unit-level circuits carrying pulse sources, and the channel impedances of circuits 1 to N can be denoted as Z1 to Z2. nFurthermore, the discharge output pulse is completed by a specific circuit within the unit-level circuitry. In the scenario where discharge is performed in the embodiment, such as... Figure 4 The diagram shown is an equivalent schematic of each circuit of the first return stroke current intrusion pulse source; Figure 4 Point G is also a ground discharge backflash point. Figure 4 The arrows in the diagram indicate the direction of the return stroke current intrusion. The impedance of the backflash channel is also Z0. Circuits 1 to N are all circuits where the first return stroke current may intrude. According to... Figure 4 It can be seen that the first return stroke current may invade each circuit from unit-level circuit 1 to circuit N. Since there are a large number of unit-level circuits connected, the voltage amplitude corresponding to the return stroke pulse can be attenuated to a certain extent according to the refractive index and reflection index of the discharge circuit and the Peterson rule, thereby eliminating the pulse energy.

[0061] S206. The second return stroke current is fed back to the pulse source.

[0062] In this embodiment, the second return stroke current is transmitted back to the pulse source via a discharge circuit, where it is absorbed. Because the transmitted second return stroke current has a lower voltage amplitude and lower pulse energy compared to the first return stroke current before pulse amplitude reduction, it causes less damage to the pulse source. Furthermore, in specific implementations, the number of unit-level circuits connected to the discharge circuit can be varied; for example, connecting more unit-level sub-circuits can increase the reduction in the pulse amplitude of the first return stroke current, resulting in a second return stroke current with a lower voltage amplitude and less damage to the pulse source, thus achieving safer discharge return stroke protection. The process of implementing discharge return stroke protection in this embodiment is relatively simple, requiring only the connection of several unit-level sub-circuits to adjust the equivalent impedance in the discharge circuit. This can meet the impedance requirements in different scenarios, achieving good pulse source discharge return stroke protection and demonstrating good adaptability.

[0063] In one embodiment, such as Figure 5 As shown, the step of obtaining the first return stroke current formed by the external discharge of the pulse source in the method may include steps S502-S504:

[0064] S502, Obtain the reflected current and refracted current generated by the pulse source's external discharge.

[0065] In this embodiment, the presence of a grounding point in the discharge circuit disrupts the uniformity of the discharge circuit. Therefore, the electromagnetic pulse wave during the discharge process, as the incident wave, will exhibit reflection and refraction phenomena at the grounding point. The current formed by the reflected wave is called the reflected current, and the current formed by the refracted wave is called the refracted current.

[0066] S504. The reflected current and the refracted current are added together to form the first return stroke current.

[0067] The reflected current and the refracted current are components of the first return stroke current. It should be noted that, in some feasible embodiments, the first return stroke current may be composed solely of either the reflected current or the refracted current.

[0068] For example, after the discharge current in the discharge circuit reaches the grounded end, a negative total reflection occurs, resulting in a corresponding reflected current. Therefore, in this embodiment, the first return stroke current in the discharge circuit is directly formed by the reflected current.

[0069] In one embodiment, the step of obtaining the reflected current and refracted current generated by the external discharge of the pulse source may include the following steps:

[0070] Step 1: Obtain the incident voltage for external discharge.

[0071] The incident voltage refers to the potential difference between the pulse source and the ground point or other low potential points during the process of the pulse source discharging externally through the discharge circuit.

[0072] For example, during the grounding discharge process through the discharge circuit, a potential difference is formed by a high-power pulse source, which is the incident voltage.

[0073] Step 2: Determine the refracted voltage based on the product of the refractive index of the external discharge path and the incident voltage; determine the reflected voltage based on the product of the reflection index of the external discharge path and the incident voltage.

[0074] The refractive index and reflection index are usually determined by the impedance at both ends of the node.

[0075] For example, in the embodiment, the incident voltage generated by the pulse source discharge is an infinitely long right-angle wave u 1f Discharge is transferred from line 1 to line 2; where the impedance value of line 1 is denoted as Z1 and the impedance value of line 2 is denoted as Z2, the voltage reflection coefficient β at the node between line 1 and line 2 satisfies the following calculation formula:

[0076]

[0077] The voltage refraction coefficient α between line 1 and line 2 satisfies the following calculation formula:

[0078]

[0079] After determining the reflection coefficient β and refractive index α at the node, the refracted voltage u generated at that node can be obtained. 1b The following calculation formula is satisfied:

[0080] u 1b =βu 1f

[0081] The reflected voltage generated at the node satisfies the following calculation formula:

[0082] u 1a =αu 1f

[0083] Furthermore, the traveling wave transmission process of the pulse source discharging to ground through the microstrip antenna and grounding resistor in the embodiment can be equivalent to the traveling wave short-circuiting (grounding) at the end of the line, i.e., Z2 = 0. For example... Figure 6 The diagram shown illustrates voltage wave transmission and reflection. Figure 6 In the diagram, point A is the grounding point, u′1 is the incident voltage, u″1 is the reflected voltage, and Z1 is the equivalent impedance in the line where the pulse source is located, i.e., the first equivalent impedance. Furthermore, in this embodiment, the voltage incident wave will undergo negative total reflection after reaching the grounded end, resulting in the voltage at the line end dropping to zero and gradually developing in the reverse direction towards the line beginning. This is determined by the boundary condition of a short circuit (grounding) at the line end; therefore, α = 0, β = -1, and consequently, the refracted voltage u′2 = 0, and the reflected voltage u″1 = -u′1.

[0084] Step 3: Generate refracted current based on the refracted voltage and the first equivalent impedance of the external discharge path; generate reflected current based on the reflected voltage and the first equivalent impedance of the external discharge path.

[0085] The first equivalent impedance refers to the equivalent impedance in the line where the pulse source is located. In the embodiment, after determining the reflected voltage and the refracted voltage through the incident voltage, the reflected current and the refracted current in the line can be directly determined by Ohm's law.

[0086] For example, such as Figure 7 As shown, in the embodiment where the line is short-circuited (grounded), A is the grounding point, Z1 is the equivalent impedance in the line where the pulse source is located, i.e., the first equivalent impedance, i′1 is the incident current, and i″ is the reflected current. Since the refracted voltage is 0, there is no refracted current in the line. The reflected current i″ satisfies the following calculation formula:

[0087]

[0088] Ultimately, the total current in the line is i1 = 2i′1, meaning the current at the end of the line increases to twice that of the incident current wave. This state gradually moves towards the beginning of the line. It should be noted that although the reflected traveling wave will not enter the interior of the conductor due to the skin effect, the conductor can still reflect and guide the traveling wave to invade the various circuits and devices of the pulse source, and its current amplitude is twice that of the original traveling wave current amplitude.

[0089] In one embodiment, the step of increasing the number of connected unit-level sub-circuits to reduce the pulse amplitude of the first return stroke current and obtain a second return stroke current with reduced pulse amplitude can be as follows:

[0090] Step 1: Obtain the second equivalent impedance of the connected unit-level sub-circuit.

[0091] For example, in this embodiment, n overhead lines are connected to the busbar of a substation. These overhead lines connected to the busbar are unit-level sub-circuits. All overhead lines have the same impedance, denoted as Z. Therefore, the second equivalent impedance in this embodiment is the impedance of each overhead line.

[0092] Step 2: Reduce the pulse amplitude of the voltage value corresponding to the return current based on the second equivalent impedance.

[0093] For example, such as Figure 8 As shown, n overhead lines 602 are connected to busbar 802 in a substation. All overhead lines have the same impedance, Z. When one of these lines is struck by lightning, an overvoltage wave U0 enters the substation along that line. Because there are many overhead lines 804 connected to busbar 802, the amplitude of the intrusion pulse can be effectively reduced.

[0094] More specifically, in the embodiments, since the wave impedance of overhead lines is approximately the same, according to Figure 8 The wiring diagram shown can be used to obtain the following: Figure 9 The circuit diagram shown is an equivalent circuit diagram of the current-carrying circuit. According to... Figure 9 The equivalent circuit diagram shown, along with Peterson's rule, indicates that the current I in this equivalent circuit diagram satisfies the following calculation formula:

[0095]

[0096] Where U0 is the overvoltage generated when struck by lightning, n is the number of overhead lines, and Z is the impedance of the overhead lines. Furthermore, the voltage U in the busbar at this time... bb That is, the voltage U obtained after the overvoltage wave U0 is reduced in amplitude by n overhead lines in the entire discharge circuit. bb It satisfies the following calculation formula:

[0097]

[0098] or:

[0099]

[0100] Through voltage U bbThe calculation formula clearly shows that in this embodiment, the more lines connected to the substation busbar, the lower the overvoltage on the busbar. According to Ohm's law, the current value in each overhead line can be determined; with constant impedance, the voltage U... bb The smaller the value, the smaller the current transmitted to each overhead line; that is, the more unit-level sub-circuits connected to the discharge circuit in the embodiment, the better the weakening effect on the back stroke current generated by the discharge.

[0101] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0102] like Figure 10 As shown, the technical solution of this application also provides a protection circuit for pulse source discharge backstroke, which includes a ground discharge module 101 and a backstroke attenuation module 103.

[0103] Among them, the ground discharge module 101 collects the external discharge of the external pulse source 105 to generate the return stroke current and outputs the return stroke current to the return stroke attenuation module 103; the return stroke attenuation module 103 reduces the pulse amplitude of the return stroke current by adjusting the number of conduction of the built-in unit-level sub-circuits and sends the pulse amplitude-reduced return stroke current to the external pulse source 105.

[0104] Since this protection circuit is based on the same inventive concept as the aforementioned protection method, and the solution provided by the protection circuit is similar to the solution described in the above method, its specific implementation method can be referred to the content provided in the method embodiment, and will not be repeated here.

[0105] In some alternative implementations, the ground discharge module includes a microstrip antenna and a grounding resistor, and the return stroke current includes reflected current and refracted current.

[0106] The microstrip antenna is connected to an external pulse source through a return stroke attenuation module, and the grounding resistor is connected to the external pulse source through the return stroke attenuation module. The microstrip antenna generates reflected current and refracted current during electromagnetic pulse radiation. The grounding resistor generates reflected current and refracted current during grounding discharge.

[0107] The microstrip antenna in this embodiment is a type of antenna fed by a microstrip line or coaxial line, and the pulse source can radiate electromagnetic pulses outward through the microstrip antenna. The grounding resistance in this embodiment is the resistance encountered when the pulse flows from the grounding point into the earth and then through the earth to another grounding body or diffuses to a distant location. This resistance is mainly used to achieve the functions of grounding protection, anti-static grounding, and lightning protection grounding. Exemplarily, in this embodiment, the high-power pulse source generally forms a discharge circuit to ground through the connection of the microstrip antenna and the matching resistor. During the discharge process, due to direct grounding, a huge return pulse current is generated. This pulse current is reflected along the matching resistor and the microstrip antenna to the pulse source connected outside the discharge circuit. More specifically, the return pulse current in this embodiment can include reflected current and refracted current. Since both the microstrip antenna and the matching resistor change the uniformity of the line, emission and refraction may occur at the connection point between the microstrip antenna and the matching resistor, generating reflected current and refracted current, ultimately forming the return pulse current.

[0108] In one embodiment, the unit-level sub-circuit in the circuit includes several ground protection sub-circuits connected in parallel.

[0109] One end of the grounding protection sub-circuit is grounded, and the other end is connected to an external pulse source.

[0110] In the embodiment, the numerous circuits for the counter-current intrusion pulse effectively reduce the amplitude of the intrusion pulse. However, other pulse sources may also be present in the unit-level sub-circuits. Since the pulse source circuit is part of the protected object, relying on multiple circuits to reduce the amplitude of the intrusion pulse may damage the pulse source in the unit-level sub-circuit. Therefore, replacing the sub-circuit carrying the pulse source in the return stroke attenuation module with a grounding protection sub-circuit can effectively avoid damage to the pulse source of the sub-circuit.

[0111] For example, such as Figure 11 As shown, in a certain embodiment, the return stroke attenuation module has 6 grounding points, and its channel impedances are Z1 to Z6 respectively. Each circuit of the pulse source is only equivalent to one or several parts of all channels. Figure 11 The arrows in the diagram indicate the direction of the return stroke current. According to Peterson's law, before the reflected wave enters the circuit, its amplitude and energy are attenuated and eliminated by the return stroke attenuation module, thus effectively reducing the harm.

[0112] It should be noted that, as Figure 12 As shown, in this embodiment, the unit-level sub-circuit in the return stroke attenuation module can be grounded at multiple points, but several grounding terminals can be led out from the same end, such as... Figure 12The grounding method shown can more accurately keep the equivalent impedance of the unit-level sub-circuits consistent, and makes it easier to accurately control the overall access impedance of the return stroke attenuation module.

[0113] In one embodiment, the return stroke attenuation module further includes a ground bus, and one end of the ground protection sub-circuit is grounded through the ground bus;

[0114] Alternatively, the return stroke attenuation module may also include a metal braid, with one end of the ground protection sub-circuit grounded through the metal braid.

[0115] The primary function of the grounding busbar is to equalize voltage, and it can further provide overvoltage protection for the discharge circuit and external pulse sources. The metal braided components in the embodiments may include, but are not limited to, metal braided strips and metal braided mesh; specifically, in the embodiments, the main function of the metal braided components is to introduce abnormal current into the ground and rapidly diffuse it, preventing damage to the line. Additionally, the grounding terminal in the embodiments can use easy-to-install locking clips or wiring lugs.

[0116] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method of protecting against a back strike of a pulse source discharge, characterized by, The method comprises: acquiring a first back strike current formed by external impulse source external discharge; increasing the number of accessed unit level sub-circuits to perform pulse amplitude reduction on the first back strike current through the accessed unit level sub-circuits to obtain a second back strike current after pulse amplitude reduction; the unit level sub-circuit comprises a plurality of grounding protection sub-circuits connected in parallel; one end of the grounding protection sub-circuit is grounded, and the other end of the grounding protection sub-circuit is connected to the external impulse source; returning the second back strike current to the external impulse source.

2. The method of claim 1, wherein, The acquiring of the first back strike current formed by external impulse source external discharge comprises: acquiring a reflected current and a refracted current formed by external discharge of the impulse source; adding the reflected current and the refracted current to form the first back strike current.

3. The method of claim 2, wherein, The acquiring of the reflected current and the refracted current formed by external discharge of the impulse source comprises: acquiring an incident voltage of external discharge; determining a refracted voltage according to the product of the refractive coefficient of the external discharge path and the incident voltage, and determining a reflected voltage according to the product of the reflection coefficient of the external discharge path and the incident voltage; generating the refracted current according to the refracted voltage and the first equivalent impedance of the external discharge path, and generating the reflected current according to the reflected voltage and the first equivalent impedance of the external discharge path.

4. The method of claim 1, wherein, The increasing of the number of accessed unit level sub-circuits to perform pulse amplitude reduction on the first back strike current through the accessed unit level sub-circuits to obtain a second back strike current after pulse amplitude reduction comprises: acquiring a second equivalent impedance of the accessed unit level sub-circuit; performing pulse amplitude reduction on the voltage value corresponding to the back strike current according to the second equivalent impedance.

5. The method of claim 4, wherein, The voltage value corresponding to the second back strike current satisfies the following calculation formula: wherein, is a voltage value after pulse amplitude reduction, is a voltage value before pulse amplitude reduction, is an impedance value of the second equivalent impedance, is a current value of the back strike current, is the number of unit-level sub-circuits.

6. A protection circuit for a pulse source discharge kickback, characterized by The grounding discharge module and the back strike attenuation module are included: The grounding discharge module collects the first back strike current generated by external discharge of the external impulse source and outputs the first back strike current to the back strike attenuation module; the back strike attenuation module performs pulse amplitude reduction on the first back strike current by adjusting the number of turned-on unit level sub-circuits, and sends the second back strike current after pulse amplitude reduction to the external impulse source; The unit level sub-circuit comprises a plurality of grounding protection sub-circuits connected in parallel; one end of the grounding protection sub-circuit is grounded, and the other end of the grounding protection sub-circuit is connected to the external impulse source.

7. The protection circuit of claim 6, wherein, The grounding discharge module comprises a microstrip antenna and a grounding resistor, and the first back strike current comprises a reflected current and a refracted current; The microstrip antenna is connected to the external impulse source through the back strike attenuation module, and the grounding resistor is connected to the external impulse source through the back strike attenuation module; The microstrip antenna generates reflected current and refracted current during electromagnetic pulse radiation; The grounding resistor generates reflected current and refracted current during grounding discharge.

8. The protection circuit according to claim 6, wherein The back strike attenuation module further comprises a grounding busbar, and one end of the grounding protection sub-circuit is grounded through the grounding busbar.

9. The protection circuit of claim 6, wherein, The back strike attenuation module includes a metal braid, one end of the ground protection sub-circuit is grounded through the metal braid.

10. A pulsed electronic device, characterized by The protection circuit as claimed in any one of claims 6-9, further comprising a pulse source connected to the ground discharge module and the back strike attenuation module of the protection circuit.

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