Control method of lightning arrester device and lightning arrester system

Abstract

The invention discloses a control method of a lightning arrester device and a lightning arrester system. The lightning arrester device comprises a first lightning arrester, a second lightning arrester and a hemispherical gap, the control method comprises the following steps: acquiring the gradient of lightning intrusion waves; determining a difference voltage according to the gradient of the lightning invasion wave, the distance between the lightning arrester device and a circuit breaker on the transformer substation line and the light velocity; the difference voltage is the voltage rise of the fracture voltage of the circuit breaker relative to the residual voltage of the end part of the lightning arrester device; and adjusting the gap distance according to the size relationship of the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap. The dynamic state of the volt-ampere characteristic of the lightning arrester device can be dynamically adjusted, so that when the lightning arrester device faces continuous lightning stroke, key equipment such as a breaker fracture and a transformer winding can be better protected, and equipment damage and power failure risks of a power grid caused by lightning invasion waves are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of overvoltage protection, and in particular to a control method of a lightning arrester device and a lightning arrester system. Background Art

[0002] With the continuous development of power systems and the expansion of power grids, lightning arresters, as important devices to protect power equipment from overvoltage hazards, are becoming increasingly important. However, most existing lightning arresters have fixed volt-ampere characteristics, which means that under continuous lightning strikes, lightning arresters cannot effectively protect the circuit breaker break, increasing the risk of heavy breakdown of the insulation medium at the break. Summary of the invention

[0003] The present invention provides a control method and a lightning arrester system for a lightning arrester device, which can dynamically adjust the volt-ampere characteristics of the lightning arrester device so that the lightning arrester device can better protect key equipment such as circuit breaker breaks and transformer windings when facing continuous lightning strikes, thereby reducing the risk of equipment damage and power outages caused by lightning intrusion waves.

[0004] In a first aspect, an embodiment of the present invention provides a control method for a lightning arrester device, the lightning arrester device comprising a first lightning arrester, a second lightning arrester and a hemispherical gap; the first end of the first lightning arrester is connected to the substation line, the second end of the first lightning arrester is respectively connected to the second lightning arrester and the first end of the hemispherical gap, and the second ends of the second lightning arrester and the hemispherical gap are both grounded; the control method comprises: obtaining the steepness of a lightning intrusion wave; determining a differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and a circuit breaker on the substation line, and the speed of light; the differential voltage is a voltage rise of a break voltage of the circuit breaker relative to a residual voltage at an end of the lightning arrester device; adjusting the gap distance according to a relationship between the differential voltage and the product of a breakdown field strength of the hemispherical gap and a gap distance of the hemispherical gap.

[0005] Optionally, the step of adjusting the gap distance of the hemispherical gap according to the difference voltage and the breakdown field strength of the hemispherical gap includes: when the difference voltage is less than the product of the breakdown field strength of the hemispherical gap and the gap distance, controlling the gap distance to remain unchanged; when the difference voltage is greater than the product of the breakdown field strength of the hemispherical gap and the gap distance, controlling the gap distance to increase so that the gap distance is greater than the ratio of the difference voltage to the breakdown field strength of the hemispherical gap.

[0006] Optionally, the maximum value of the gap distance is smaller than the ratio of the rated voltage of the second lightning arrester to the breakdown field strength of the hemispherical gap.

[0007] Optionally, before the step of adjusting the gap distance according to the magnitude relationship between the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap, the control method further comprises: determining the gap distance d according to the following formula:

[0008]

[0009] Among them, U g represents the breakdown voltage of the hemispherical gap, E d Represents the breakdown field strength of the hemispherical gap.

[0010] Optionally, the step of obtaining the steepness of the lightning intrusion wave includes: obtaining a first voltage at the end of the lightning arrester device at a first moment and a second voltage at a second moment at the moment of lightning strike; determining the steepness of the lightning intrusion wave according to the ratio of the voltage difference to the time difference; wherein the voltage difference is the difference between the second voltage and the first voltage, and the time difference is the difference between the second moment and the first moment.

[0011] Optionally, the step of determining the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light includes:

[0012] The differential voltage ΔU is determined according to the following formula:

[0013]

[0014] Among them, a is the steepness of the lightning intrusion wave, l2 is the distance between the lightning arrester device and the circuit breaker on the substation line, and c is the speed of light in vacuum.

[0015] Optionally, the rated voltage of the first lightning arrester is a first rated voltage, the rated voltage of the second lightning arrester is a second rated voltage, and the first rated voltage is greater than the second rated voltage.

[0016] In a second aspect, an embodiment of the present invention provides a lightning arrester system, including a lightning arrester device and a control device, wherein the lightning arrester device is communicatively connected to the control device, and the control device is used to execute the control method of the lightning arrester device provided by any embodiment of the present invention.

[0017] Optionally, the lightning arrester system further comprises a voltage acquisition device, which is connected to the control device and installed at the end of the lightning arrester device, and is used to obtain the voltage at the end of the lightning arrester device at the moment of lightning strike.

[0018] Optionally, the lightning arrester system also includes a first communication device and a second communication device; the voltage collection device is connected to the control device through the first communication device, and the first communication device is used to transmit the data collected by the voltage collection device to the control device; the lightning arrester device is connected to the control device through the second communication device, and the second communication device is used to transmit the control signal sent by the control device to the lightning arrester device; the lightning arrester device adjusts the gap distance of the hemispherical gap according to the control signal.

[0019] The control method of the lightning arrester device provided by the embodiment of the present invention adjusts the gap distance of the hemispherical gap according to the size relationship between the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap. For example, when the lightning arrester device operates at a normal operating voltage, it is ensured that the difference voltage is less than the product of the breakdown field strength and the gap distance, and the hemispherical gap is ensured to be in a non-conducting state. When a high-voltage lightning strikes, the hemispherical gap is quickly turned on, opening up a low-resistance channel for the discharge of lightning energy, and instantly reducing the residual pressure at the end of the lightning arrester device. In order to prevent the hemispherical gap from being broken down and damaged, it is necessary to control the increase of the gap distance, increase the breakdown voltage threshold, change the current-voltage distribution relationship, so that the lightning arrester device is turned on only at a higher voltage, reduce the voltage segment current, and optimize the slope and threshold of the volt-ampere characteristic curve, thereby dynamically adjusting the volt-ampere characteristics of the lightning arrester device.

[0020] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a structural schematic diagram of a lightning arrester device provided by an embodiment of the present invention;

[0023] Figure 2 It is the equivalent wiring diagram for calculating the overvoltage of lightning intrusion wave;

[0024] Figure 3 is a flow chart of a control method of a lightning arrester device provided by an embodiment of the present invention;

[0025] Figure 4 is a schematic diagram of a lightning intrusion wave provided by an embodiment of the present invention;

[0026] Figure 5 is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention;

[0027] Figure 6 is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention;

[0028] Figure 7 is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention;

[0029] Figure 8 is a structural schematic diagram of a lightning arrester system provided by an embodiment of the present invention;

[0030] Fig. 9 It is a structural schematic diagram of another lightning arrester system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] In order to solve the problems in the prior art, an embodiment of the present invention provides a control method for a lightning arrester device and a lightning arrester system. Firstly, a lightning arrester device to which the control method for a lightning arrester device provided by an embodiment of the present invention can be applied is introduced below.

[0034] Figure 1 It is a structural schematic diagram of a lightning arrester device provided in an embodiment of the present invention. Figure 2 It is the equivalent wiring diagram for calculating the overvoltage of lightning intrusion wave. Figure 1 and Figure 2 As shown, the arrester device includes a first arrester 1, a second arrester 2 and a hemispherical gap 3. The first end of the first arrester 1 is connected to the substation line, the second end of the first arrester 1 is connected to the second arrester 2 and the first end of the hemispherical gap 3 respectively, and the second ends of the second arrester 2 and the hemispherical gap 3 are both grounded.

[0035] Among them, the first lightning arrester 1 is responsible for protecting the power grid in the early stage of lightning strike. It has a higher rated voltage and plays the role of absorbing energy and reducing voltage amplitude when lightning strikes. The first lightning arrester 1 is connected in series in the system, and its rated voltage U1 is higher than the rated voltage U2 of the second lightning arrester 2. Its position determines that it can first absorb voltage and provide protection when the lightning strike energy is large.

[0036] The main function of the second lightning arrester 2 is to continue to absorb energy in the subsequent stages of the lightning strike to ensure the continued stability of the system. Due to its low rated voltage, in the early stage of the lightning strike, after the first lightning arrester 1 is activated, the second lightning arrester 2 will further share the remaining lightning energy and enhance the overall protection effect.

[0037] The hemispherical gap 3 is composed of two hemispherical electrodes. The distance between the electrodes determines the size of the gap distance. Its appearance is a spherical object cut along the central axis to produce a gap. It has a simple structure and a relatively uniform distribution of the electric field. It is suitable for overvoltage protection in high-voltage electrical equipment.

[0038] The function of the hemispherical gap 3 is to provide segmented dynamically adjustable volt-ampere characteristics. Under normal operating voltage, the hemispherical gap 3 is not conductive; when a high voltage lightning strikes, the hemispherical gap 3 quickly conducts, reducing the residual pressure at the end of the arrester device and providing an additional layer of protection. Normal operating voltage refers to the voltage that the arrester device withstands under daily working conditions, which is lower than the rated voltage of the arrester device.

[0039] Optionally, the rated voltage of the first lightning arrester 1 is a first rated voltage, the rated voltage of the second lightning arrester 2 is a second rated voltage, and the first rated voltage is greater than the second rated voltage.

[0040] Figure 3 1 is a flow chart of a control method of a lightning arrester device provided by an embodiment of the present invention. The method of this embodiment can be executed by a control device of the lightning arrester device, and the control device can be implemented in software and / or hardware and can be integrated in the lightning arrester system. Figure 3 , the control method comprises:

[0041] S101. Obtain the steepness of a lightning intrusion wave.

[0042] In some embodiments, the voltage value at the end of the lightning arrester device at different times at the moment of lightning strike can be obtained by a voltage acquisition device, such as obtaining a first voltage at a first moment and obtaining a second voltage at a second moment immediately thereafter. Then, the second voltage is subtracted from the first voltage, and this difference reflects the voltage variation in this small time interval, and then divided by the time difference between the second moment and the first moment, and the result is the steepness of the lightning intrusion wave.

[0043] S102. Determine the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light.

[0044] The differential voltage is the voltage rise of the circuit breaker's break voltage relative to the residual voltage at the end of the arrester device.

[0045] Figure 4 FIG. 1 is a schematic diagram of a lightning intrusion wave provided by an embodiment of the present invention. Figure 4 As shown in the figure, the lightning intrusion wave can be regarded as a traveling wave, and the lightning wave is characterized as an oblique wave:

[0046] u(t) = at;

[0047] Where a is the steepness, u(t) is the change of voltage over time, and t is time. When the arrester device reaches the residual voltage moment t f When the arrester is installed, a negative voltage wave -at(tt f ); the voltage value is then maintained at the residual voltage U b .

[0048] Since the equivalent capacitance of the line-side circuit breaker is not large, its influence can be ignored and the break can be considered as an open circuit. Therefore, the equivalent wiring is as follows: Figure 2 As shown. The distance between the lightning strike point A and the connection point B of the lightning arrester device is l1, and the distance between the break point D and the connection point B of the lightning arrester device is l2. Since the lightning wave is fully reflected at the break point D of the circuit breaker, the voltage at the break point D will be higher than the voltage Ub at the end of the lightning arrester.

[0049] (i.e. the residual pressure of the arrester)

[0050] According to the traveling wave theory, the moment when the voltage appears at each point is taken as the time zero of each point, and the voltage U on the line side of the break is obtained. D for:

[0051]

[0052] Here, c is the speed of light in a vacuum.

[0053] It can be seen that due to the distance between the installation position of the lightning arrester and the break of the circuit breaker, the maximum break voltage must be higher than the end voltage of the lightning arrester (residual voltage U b ), the difference voltage is:

[0054]

[0055] S103, adjusting the gap distance according to the magnitude relationship of the difference voltage, the breakdown field strength of the hemispherical gap, and the gap distance of the hemispherical gap.

[0056] The differential voltage is the increase in the voltage at the circuit breaker break relative to the residual voltage at the end of the arrester, reflecting the degree of overvoltage in the power system. The breakdown field strength of the hemispherical gap depends on the material and structure, which is an inherent property; the gap distance can be flexibly adjusted.

[0057] When the differential voltage changes, such as due to changes in the grid structure, lightning intensity or position, the gap distance is adjusted based on the relationship with the product of the breakdown field strength of the hemispherical gap and the gap distance. If the differential voltage rises to exceed the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap, the gap distance is increased to increase the breakdown voltage threshold, change the current-voltage distribution relationship, make the arrester device conduct at a higher voltage, reduce the current in the low-voltage section, optimize the slope and threshold of the volt-ampere characteristic curve, and achieve dynamic adjustment. This adjustment ensures that the arrester device is adapted to different working conditions, effectively reduces residual pressure and enhances protection capabilities in high lightning intensity or complex grid environments, improves the flexibility and reliability of the power system in dealing with overvoltages, prevents equipment insulation damage and failures, and ensures stable operation of the grid.

[0058] Determine the gap distance d according to the following formula:

[0059] Among them, U g represents the breakdown voltage of the hemispherical gap, E d Represents the breakdown field strength of the hemispherical gap.

[0060] For example, assuming that the breakdown field strength E of the hemispherical gap is b =50kV / cm, initial gap distance d0 = 2cm, calculated difference voltage ΔU = 120kV. At this time, difference voltage ΔU>E d ·d0, in order to enhance the protection, the gap distance needs to be increased. Let the adjusted gap distance be d1. By ΔU<E d ·d0 can be obtained At this time, d1=2.5cm.

[0061] The control method of the lightning arrester device provided by the embodiment of the present invention adjusts the gap distance of the hemispherical gap according to the size relationship between the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap. For example, when the lightning arrester device operates at a normal operating voltage, it is ensured that the difference voltage is less than the product of the breakdown field strength and the gap distance, and the hemispherical gap is ensured to be in a non-conducting state. When a high-voltage lightning strikes, the hemispherical gap is quickly turned on, opening up a low-resistance channel for the discharge of lightning energy, and instantly reducing the residual pressure at the end of the lightning arrester device. In order to prevent the hemispherical gap from being broken down and damaged, it is necessary to control the increase of the gap distance, increase the breakdown voltage threshold, change the current-voltage distribution relationship, so that the lightning arrester device is turned on only at a higher voltage, reduce the voltage segment current, and optimize the slope and threshold of the volt-ampere characteristic curve, thereby dynamically adjusting the volt-ampere characteristics of the lightning arrester device.

[0062] Figure 5 This is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention.

[0063] like Figure 5 As shown, the control method includes:

[0064] S201. Obtain the steepness of a lightning intrusion wave.

[0065] S202. Determine the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light.

[0066] S203. When the difference voltage is smaller than the product of the breakdown field strength of the hemispherical gap and the gap distance, the gap distance is controlled to remain unchanged.

[0067] Specifically, when the difference voltage is less than the product of the breakdown field strength of the hemispherical gap and the gap distance, it means that the voltage at both ends of the hemispherical gap is less than the rated voltage of the second arrester. Maintaining a stable gap distance can ensure the reliable insulation performance of the arrester device. This effectively prevents abnormal current leakage and malfunction, ensures continuous and smooth power transmission, lays a solid foundation for the reliable operation of the power system, stabilizes the power supply order, reduces the risk of failures caused by unnecessary adjustments, and improves the stability and reliability of system operation.

[0068] S204. When the difference voltage is greater than the product of the breakdown field strength of the hemispherical gap and the gap distance, control the gap distance to increase so that the gap distance is greater than the ratio of the difference voltage to the breakdown field strength of the hemispherical gap.

[0069] Specifically, when a high-voltage lightning strikes, the hemispherical gap quickly conducts, opening up a low-resistance channel for the discharge of lightning energy and instantly reducing the residual pressure at the end of the arrester device. In order to prevent the hemispherical gap from being damaged by breakdown, it is necessary to control the increase of the gap distance, increase the breakdown voltage threshold, and change the current-voltage distribution relationship so that the arrester device will only conduct at a higher voltage, reduce the current in the low-voltage section, and optimize the slope and threshold of the volt-ampere characteristic curve, thereby dynamically adjusting the volt-ampere characteristics of the arrester device.

[0070] Optionally, the maximum value of the gap distance is less than the ratio of the rated voltage of the second lightning arrester to the breakdown field strength of the hemispherical gap. That is, when a high voltage lightning strike occurs, in order to ensure that the hemispherical gap is turned on before the second lightning arrester, the gap distance d should also meet the following conditions:

[0071]

[0072] Among them, U g is the breakdown voltage of the hemispherical gap, E b is the breakdown field strength of the hemispherical gap, and U2 is the rated voltage of the second lightning arrester.

[0073] Figure 6 This is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention.

[0074] like Figure 6 As shown, the control method includes:

[0075] S301, obtaining a first voltage at a first moment and a second voltage at a second moment at an end of a lightning arrester device at the moment of a lightning strike.

[0076] S302: Determine the steepness of the lightning intrusion wave according to the ratio of the voltage difference to the time difference.

[0077] The voltage difference is the difference between the second voltage and the first voltage, and the time difference is the difference between the second moment and the first moment.

[0078] Specifically, the steepness of the lightning intrusion wave is calculated according to the following formula:

[0079]

[0080] Wherein, a is the steepness of the lightning intrusion wave, U(t1) is the first voltage, U(t2) is the second voltage, t1 is the first moment, and t2 is the second moment.

[0081] S303, determining the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light.

[0082] S304, determining the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light.

[0083] Figure 7 This is a flow chart of another method for controlling a lightning arrester device provided by an embodiment of the present invention.

[0084] like Figure 7 As shown, the control method includes:

[0085] S401, obtaining a first voltage at a first moment and a second voltage at a second moment at an end of a lightning arrester device at the moment of a lightning strike.

[0086] S402: Determine the steepness of the lightning intrusion wave according to the ratio of the voltage difference to the time difference.

[0087] S403, determining the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light.

[0088] S404. When the difference voltage is smaller than the product of the breakdown field strength of the hemispherical gap and the gap distance, the gap distance is controlled to remain unchanged.

[0089] S405. When the difference voltage is greater than the product of the breakdown field strength of the hemispherical gap and the gap distance, control the gap distance to increase so that the gap distance is greater than the ratio of the difference voltage to the breakdown field strength of the hemispherical gap.

[0090] Based on the same inventive concept, an embodiment of the present invention further provides a lightning arrester system. Figure 8 Schematic diagram of the structure of a lightning arrester system provided by an embodiment of the present invention. Figure 8 As shown, the lightning arrester system includes a lightning arrester device 11 and a control device 12. The lightning arrester device 11 is in communication connection with the control device 12. The control device is used to execute the control method of the lightning arrester device provided in any embodiment of the present invention.

[0091] Optionally, the control device 12 may include a microcontroller. Exemplarily, the control device 12 may include a single chip microcomputer, a digital signal processor (DSP) or a field programmable gate array (FPGA).

[0092] Fig. 9 FIG. 1 is a schematic diagram of the structure of another lightning arrester system provided by an embodiment of the present invention. Fig. 9 As shown, optionally, the arrester system further includes a voltage acquisition device 13, which is connected to the control device 12 and installed at the end of the arrester device 11, for acquiring the voltage at the end of the arrester device at the moment of lightning strike.

[0093] Continue to refer Fig. 9 Optionally, the lightning arrester system also includes a first communication device 14 and a second communication device 15; the voltage acquisition device 13 is connected to the control device 12 through the first communication device 14, and the first communication device 14 is used to transmit the data collected by the voltage acquisition device 13 to the control device 12; the lightning arrester device 11 is connected to the control device 12 through the second communication device 15, and the second communication device 15 is used to transmit the control signal sent by the control device 12 to the lightning arrester device 11; the lightning arrester device 11 adjusts the gap distance of the hemispherical gap according to the control signal.

[0094] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a lightning arrester device, characterized in that: The lightning arrester device comprises a first lightning arrester, a second lightning arrester and a hemispherical gap; a first end of the first lightning arrester is connected to a substation line, a second end of the first lightning arrester is respectively connected to the second lightning arrester and the first end of the hemispherical gap, and second ends of the second lightning arrester and the hemispherical gap are both grounded; The control method comprises: Get the steepness of the lightning intrusion wave; Determine the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light; the differential voltage is the voltage rise of the break voltage of the circuit breaker relative to the residual voltage at the end of the lightning arrester device; The gap distance is adjusted according to a magnitude relationship between the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap.

2. The control method of the lightning arrester device according to claim 1, characterized in that: The step of adjusting the gap distance of the hemispherical gap according to the difference voltage and the breakdown field strength of the hemispherical gap comprises: When the difference voltage is less than the product of the breakdown field strength of the hemispherical gap and the gap distance, controlling the gap distance to remain unchanged; When the difference voltage is greater than the product of the breakdown field strength of the hemispherical gap and the gap distance, the gap distance is controlled to increase so that the gap distance is greater than the ratio of the difference voltage to the breakdown field strength of the hemispherical gap.

3. The control method of the lightning arrester device according to claim 2, characterized in that: The maximum value of the gap distance is smaller than the ratio of the rated voltage of the second lightning arrester to the breakdown field strength of the hemispherical gap.

4. The control method of the lightning arrester device according to claim 1, characterized in that: Before the step of adjusting the gap distance according to the magnitude relationship between the difference voltage and the product of the breakdown field strength of the hemispherical gap and the gap distance of the hemispherical gap, the control method further includes: The gap distance d is determined according to the following formula: Among them, U g represents the breakdown voltage of the hemispherical gap, E d represents the breakdown field strength of the hemispherical gap.

5. The control method of the lightning arrester device according to claim 1, characterized in that: The step of obtaining the steepness of the lightning intrusion wave comprises: Obtaining a first voltage at a first moment and a second voltage at a second moment at the end of the lightning arrester device at the moment of a lightning strike; The steepness of the lightning intrusion wave is determined according to the ratio of the voltage difference to the time difference; wherein the voltage difference is the difference between the second voltage and the first voltage, and the time difference is the difference between the second moment and the first moment.

6. The control method of the lightning arrester device according to claim 1, characterized in that: The step of determining the differential voltage according to the steepness of the lightning intrusion wave, the distance between the lightning arrester device and the circuit breaker on the substation line, and the speed of light comprises: The differential voltage ΔU is determined according to the following formula: Wherein, a is the steepness of the lightning intrusion wave, l2 is the distance between the lightning arrester device and the circuit breaker on the substation line, and c is the speed of light in vacuum.

7. The control method of the lightning arrester device according to claim 1, characterized in that: The rated voltage of the first lightning arrester is a first rated voltage, the rated voltage of the second lightning arrester is a second rated voltage, and the first rated voltage is greater than the second rated voltage.

8. A lightning arrester system, characterized in that: It comprises a lightning arrester device and a control device, wherein the lightning arrester device is communicatively connected to the control device, and the control device is used to execute the control method of the lightning arrester device according to any one of claims 1 to 7.

9. The lightning arrester system according to claim 8, characterized in that: It also includes a voltage acquisition device, which is connected to the control device and installed at the end of the lightning arrester device to obtain the voltage at the end of the lightning arrester device at the moment of lightning strike.

10. The lightning arrester system according to claim 9, characterized in that: Also included is a first communication device and a second communication device; The voltage collection device is connected to the control device via the first communication device, and the first communication device is used to transmit the data collected by the voltage collection device to the control device; The lightning arrester device is connected to the control device via the second communication device, and the second communication device is used to transmit the control signal sent by the control device to the lightning arrester device; The lightning arrester device adjusts the gap distance of the hemispherical gap according to the control signal.

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