Dynamic Configuration Method of Lightning Arresters for Offshore Wind Farms Based on Multi-Overvoltage Cooperative Suppression

Abstract

The invention discloses a dynamic configuration method for lightning arresters in offshore wind farms based on multi-overvoltage collaborative suppression, belonging to the field of lightning arrester configuration in offshore wind farms, and comprising the following steps: S1, obtaining the statistical results of offshore lightning parameters; S2, establishing a lightning electromagnetic transient simulation model for offshore wind turbines to obtain the critical lightning current corresponding to the overvoltage insulation withstand level on the cables inside the offshore wind turbines; S3, calculating the overvoltage withstand probability; S4, on the premise of considering the requirements of the operator, evaluating the lightning protection effects of multiple lightning arrester configuration schemes based on the overvoltage withstand probability to obtain the optimal lightning arrester configuration scheme. By adopting the above-mentioned dynamic configuration method for lightning arresters in offshore wind farms based on multi-overvoltage collaborative suppression, through quantifying lightning randomness, multi-index collaborative evaluation and cost-lightning protection effect balance, the limitations of traditional methods are solved, and a scientific, flexible and practical decision-making tool is provided for the lightning arrester configuration in offshore wind farms.

Description

Technical Field

[0001] The present invention relates to the technical field of arrester configuration for offshore wind farms, and particularly to a dynamic configuration method for arresters in offshore wind farms based on collaborative suppression of multiple overvoltages. Background Art

[0002] Offshore wind power is an important support for achieving the "dual carbon" goal, and its safe operation directly affects the consumption of new energy. However, since offshore wind turbines are installed on the sea surface and are relatively tall, they are extremely vulnerable to lightning strikes. After being struck by lightning, the lightning current is conducted through the blade downlead to the nacelle and the tower barrel and then enters the sea water. During this process, strong electromagnetic coupling will be generated between the wind turbine itself and the adjacent internal equipment, forming a relatively high lightning-induced overvoltage.

[0003] At the same time, since the cables in offshore wind turbines are generally close to the tower barrel, during lightning strikes, the armored layer, shielding layer, and core wire with conductive properties of the cable will generate induced voltages, which will cause overvoltages between the tower barrel and the armored layer 、overvoltages between the armored layer and the shielding layer 、overvoltages between the shielding layer and the core wire to be relatively large. Therefore, additional arresters need to be configured to suppress the above overvoltages.

[0004] The current arrester configuration technology for offshore wind farms has the following technical defects:

[0005] 1. Single evaluation dimension: Existing methods mainly focus on the suppression effect of arresters on a single overvoltage (such as the overvoltage between the tower barrel and the armored layer ), and do not systematically analyze the mutual influence of multiple overvoltages ( 、 and ) and their inconsistencies with the configuration scheme changes, making it difficult to accurately evaluate different arrester configuration schemes.

[0006] 2. Insufficient application of lightning parameters: Existing lightning protection designs lack in-depth statistical analysis of offshore lightning characteristics (such as the proportion of different return stroke orders, lightning current amplitude distribution, etc.), resulting in insufficient matching of parameter selection with the actual lightning environment.

[0007] 3. Lack of evaluation indicators: Existing technical specifications still use the overvoltage threshold as the single evaluation criterion, and do not establish a comprehensive evaluation method that combines the overvoltage tolerance ability and the lightning occurrence probability.

[0008] 4. Lack of flexibility in the scheme: Existing arrester configuration methods mostly adopt a fixed configuration mode and do not consider the different requirements of operators for cost-effectiveness and lightning protection effects. Summary of the Invention

[0009] The object of the present invention is to provide a dynamic configuration method for lightning arresters in an offshore wind farm based on multi-overvoltage collaborative suppression to solve the above technical problems.

[0010] To achieve the above object, the present invention provides a dynamic configuration method for lightning arresters in an offshore wind farm based on multi-overvoltage collaborative suppression, including the following steps:

[0011] S1. Obtain the statistical results of offshore lightning parameters based on the data of the lightning location system;

[0012] S2. Establish a lightning strike electromagnetic transient simulation model for offshore wind turbines, and conduct lightning strike simulations under multiple strike sequences to obtain the critical lightning current corresponding to the overvoltage insulation withstand level on the cables inside the offshore wind turbines;

[0013] S3. Substitute the critical lightning current obtained in step S2 into the statistical results of offshore lightning parameters obtained in step S1, and calculate the overvoltage tolerance probability;

[0014] S4. On the premise of considering the requirements of the operator, evaluate the lightning protection effects of multiple lightning arrester configuration schemes based on the overvoltage tolerance probability obtained in step S3, and obtain the optimal lightning arrester configuration scheme.

[0015] Preferably, the statistical results of the offshore lightning parameters described in step S1 include the proportion of multiple strike sequences and the lightning current amplitude distribution corresponding to the proportion of multiple strike sequences respectively. Using the lightning current amplitude cumulative probability function in IEEE, the lightning current amplitude corresponding to multiple strike sequences is fitted to obtain the lightning current amplitude cumulative probability;

[0016] Among them, the proportion of each strike sequence includes the proportion of positive single lightning strikes , the proportion of negative single lightning strikes , the proportion of positive first strikes , the proportion of negative first strikes , the proportion of positive subsequent strikes , the proportion of negative subsequent strikes ;

[0017] The lightning current amplitude cumulative probability includes the lightning current amplitude cumulative probability of positive single lightning strikes , the lightning current amplitude cumulative probability of negative single lightning strikes , the lightning current amplitude cumulative probability of positive first strikes , the lightning current amplitude cumulative probability of negative first strikes , the lightning current amplitude cumulative probability of positive subsequent strikes , the lightning current amplitude cumulative probability of negative subsequent strikes .

[0018] Preferably, the expression of the lightning current amplitude cumulative probability function is as follows:

[0019] (1);

[0020] Wherein, represents the lightning current amplitude exceeding the critical lightning current probability; is the lightning current amplitude parameter; is the shape parameter.

[0021] Preferably, step S2 specifically includes the following steps:

[0022] S21. Use PSCAD electromagnetic transient simulation software to perform segmented modeling to obtain a lightning electromagnetic transient simulation model of an offshore wind turbine:

[0023] Establish a chain equivalent circuit for the blade downlead, moving contact part, nacelle, tower barrel, and cable of the offshore wind turbine respectively;

[0024] Model the lightning arrester and surge protector using non-linear resistors;

[0025] Model the transformer in the nacelle using a high-frequency model;

[0026] Use the ground capacitance to simulate the high-frequency characteristics during the lightning strike of the switchgear at the bottom of the tower barrel;

[0027] Use Comsol finite element software to calculate the coupling capacitance between the tower barrel and the cable armor layer, between the cable armor layer and the shielding layer, between the cable shielding layers, and between the cable shielding layer and the core wire;

[0028] Use the Heidler function to simulate the lightning current waveform, and set the lightning current waveform corresponding to positive single lightning strike to 22 / 230 μs, the lightning current waveform corresponding to negative single lightning strike to 2.6 / 50 μs, the lightning current waveform corresponding to the first positive return stroke to 10 / 350 μs, the lightning current waveform corresponding to the first negative return stroke to 1 / 200 μs, and the lightning current waveforms corresponding to both positive and negative subsequent return strokes to 0.25 / 100 μs;

[0029] S22. Based on the lightning electromagnetic transient simulation model of the offshore wind turbine, perform lightning strike simulations under various lightning current waveforms to obtain the critical lightning current when the overvoltage between the tower barrel - armor layer, between the armor layer - shielding layer, and between the shielding layer - core wire reaches the insulation withstand strength. between the armor layer - shielding layer between the shielding layer - core wire reaches the insulation withstand strength.

[0030] Preferably, in step S21, the set segmented length is related to the maximum cut-off frequency of the lightning current:

[0031] (2);

[0032] Wherein, is the upper limit cut-off frequency of lightning current, with the unit of MHz; is the speed of light.

[0033] Preferably, in step S3, the overvoltage withstand probability The calculation formula is as follows:

[0034] (3);

[0035] Wherein, and in is the overvoltage , or ; is the proportion of the th return stroke order; is the cumulative probability of lightning current amplitude obtained by substituting the critical lightning current corresponding to the proportion of return stroke order into the lightning current amplitude cumulative probability function.

[0036] Preferably, in step S4, based on , and corresponding overvoltage withstand probabilities , , , evaluate the lightning protection effect, and considering the operating cost of the operator, determine the optimal arrester configuration scheme.

[0037] Therefore, the present invention adopts the above-mentioned dynamic configuration method of arrester for offshore wind farm based on multi-overvoltage collaborative suppression, and the beneficial effects are as follows:

[0038] 1. Improve the accuracy of lightning strike simulation: Through the segmented modeling technology (such as the chain equivalent circuit of blade downlead, tower barrel, and cable), accurately capture the lightning strike high-frequency transient characteristics of various overvoltages under different arrester configuration schemes, and realize the refined simulation of the lightning strike process of offshore wind turbines;

[0039] 2. Optimize the evaluation of lightning protection configuration: Adopt non-linear resistance modeling for arresters and SPDs (surge protectors), and adopt high-frequency models for transformers, which conforms to the actual electrical characteristics of the equipment, effectively simulates the overvoltage suppression process, and provides a scientific evaluation basis for the arrester configuration scheme;

[0040] 3. Multi-scenario lightning strike analysis: Use the Heidler function to simulate lightning current waveforms with different return stroke orders (such as the first return stroke, subsequent return strokes, etc.), cover a variety of lightning strike scenarios, calculate the critical lightning currents for overvoltages between the tower barrel - armored layer, armored layer - shielding layer, and shielding layer - core wire, and comprehensively evaluate the lightning strike risk of cables inside the wind turbine;

[0041] 4. Enhance the reliability of the model: Through PSCAD electromagnetic transient simulation combined with Comsol finite element software, integrate circuit analysis and electromagnetic field calculation, improve the model's ability to depict complex structures (such as cable layer - layer coupling), and ensure the reliability of the simulation results.

[0042] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0043] Figure 1 It is a flowchart of a method for dynamically configuring lightning arresters in an offshore wind farm based on multi - overvoltage collaborative suppression according to the present invention;

[0044] Figure 2 It is an equivalent wiring diagram of a lightning strike electromagnetic transient simulation model of an offshore wind turbine for the simulation experiment according to the present invention;

[0045] Figure 3 It is a configuration diagram of 5 lightning arrester schemes for the simulation experiment according to the present invention;

[0046] Figure 4 It is the overvoltage , and maximum value curve diagram for the 5 lightning arrester configuration schemes of the simulation experiment according to the present invention. Detailed Embodiments

[0047] In order to make the purpose, technical solution, and advantages of the embodiments disclosed in the present invention clearer, the following further describes the embodiments of the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope protected by this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end.

[0048] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0049] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0050] As Figure 1 shown, a dynamic configuration method for arresters in an offshore wind farm based on multi-overvoltage collaborative suppression includes the following steps:

[0051] S1. Obtain the statistical results of offshore lightning parameters based on the data of the lightning location system;

[0052] The statistical results of the offshore lightning parameters described in step S1 include the proportions of various return stroke orders and the lightning current amplitude distributions corresponding to the proportions of various return stroke orders respectively. Using the lightning current amplitude cumulative probability function in IEEE, the lightning current amplitudes corresponding to various return stroke orders are fitted to obtain the lightning current amplitude cumulative probability;

[0053] The expression of the lightning current amplitude cumulative probability function is as follows:

[0054] (1);

[0055] In the formula, represents the probability that the lightning current amplitude exceeds the critical lightning current ; is the lightning current amplitude parameter, and The units of are kA;

[0056] Among them, the proportion of each return stroke order includes the proportion of positive single-stroke lightning strikes , the proportion of negative single-stroke lightning strikes , the proportion of positive first return strokes , the proportion of negative first return strokes , the proportion of positive subsequent return strokes , the proportion of negative subsequent return strokes ;

[0057] The lightning current amplitude cumulative probability includes the lightning current amplitude cumulative probability of positive single-stroke lightning strikes , the lightning current amplitude cumulative probability of negative single-stroke lightning strikes , the lightning current amplitude cumulative probability of positive first return strokes , the lightning current amplitude cumulative probability of negative first return strokes 1. Cumulative probability of subsequent return stroke lightning current amplitude with positive polarity 2. Cumulative probability of subsequent return stroke lightning current amplitude with negative polarity .

[0058] S2. Establish a lightning electromagnetic transient simulation model for an offshore wind turbine, and conduct lightning simulations under various return stroke sequences to obtain the critical lightning current corresponding to the overvoltage insulation withstand level on the cable inside the offshore wind turbine;

[0059] Step S2 specifically includes the following steps:

[0060] S21. Use PSCAD electromagnetic transient simulation software to conduct segmented modeling to obtain a lightning electromagnetic transient simulation model for an offshore wind turbine:

[0061] Establish a chain equivalent circuit for the blade downlead, moving contact part, nacelle, tower barrel, and cable of the offshore wind turbine respectively; in this embodiment, the modeling of the moving contact part considers the equivalent resistance of the connection between the tail of the blade downlead and the hub, the connection between the hub and the nacelle, the connection between the nacelle and the tower barrel, and the capacitive effect of the oil film discharge of the bearing, slip ring or brush system during the lightning transient process.

[0062] Model the lightning arrester and surge protector using a nonlinear resistor;

[0063] Model the transformer inside the nacelle using a high-frequency model;

[0064] Use the capacitance to the ground to equivalent the high-frequency characteristics during the lightning strike of the switchgear at the bottom of the tower barrel;

[0065] Use Comsol finite element software to calculate the coupling capacitance between the tower barrel and the cable armor layer, between the cable armor layer and the shielding layer, between the cable shielding layers, and between the cable shielding layer and the core wire;

[0066] Use the Heidler function to simulate the lightning current waveform, and set the lightning current waveform corresponding to a single positive lightning strike to 22 / 230 μs, the lightning current waveform corresponding to a single negative lightning strike to 2.6 / 50 μs, the lightning current waveform corresponding to the first positive return stroke to 10 / 350 μs, the lightning current waveform corresponding to the first negative return stroke to 1 / 200 μs, and the lightning current waveform corresponding to both positive and negative subsequent return strokes to 0.25 / 100 μs;

[0067] In step S21, set the segmented length during modeling to be related to the maximum cut-off frequency of the lightning current:

[0068] (2);

[0069] where is the upper cut-off frequency of the lightning current, with the unit of MHz; is the speed of light.

[0070] S22. Based on the lightning electromagnetic transient simulation model of offshore wind turbines, conduct lightning strikes simulations under various lightning current waveforms to obtain the overvoltage between the tower barrel and the armor layer , the overvoltage between the armor layer and the shielding layer and the overvoltage between the shielding layer and the core wire at the critical lightning current corresponding to when the insulation withstand strength is reached.

[0071] S3. Substitute the critical lightning current obtained in step S2 into the statistical results of offshore lightning parameters obtained in step S1 to calculate the overvoltage tolerance probability;

[0072] In step S3, the overvoltage tolerance probability is calculated as follows:

[0073] (3);

[0074] In the formula, and in is the overvoltage , or ; is the proportion of the th return stroke order; is the cumulative probability of lightning current amplitude obtained by substituting the critical lightning current corresponding to the proportion of the return stroke order into the cumulative probability function of lightning current amplitude.

[0075] S4. On the premise of considering the operator's requirements, evaluate the lightning protection effect of various arrester configuration schemes based on the overvoltage tolerance probability obtained in step S3 to obtain the optimal arrester configuration scheme.

[0076] In step S4, based on , and corresponding overvoltage tolerance probabilities , , , evaluate the lightning protection effect, and consider the operator's wind farm area and scale, retrofit cost, and operation cost to determine the optimal arrester configuration scheme. As follows:

[0077] (4);

[0078] In the formula, is the comprehensive evaluation index; takes the minimum value among , , , is the lightning strike frequency of the wind farm, with the unit of times / year. is the maintenance cost and power outage loss caused by a single overvoltage limit violation. is the cost of the newly added lightning arrester. is the retrofit cost. is the depreciation rate. is the annual operation and maintenance cost of the newly added lightning arrester.

[0079] When is closer to 0, it represents the best corresponding scheme, which is the optimal lightning arrester configuration scheme.

[0080] Simulation experiment

[0081] Select the data collected by the lightning current positioning system in a certain province from 2014 to 2023 for a total of ten years, statistically analyze the offshore data to carry out lightning current parameters, and statistically obtain the proportion of various return stroke orders .

[0082] Table 1 Statistical results of the proportion of various return stroke orders

[0083] ;

[0084] Based on the results described in Table 1, Table 2 is obtained after fitting using formula (1).

[0085] Table 2 Fitting results of the lightning current amplitude cumulative probability formula

[0086] ;

[0087] Based on the data in Table 2, for a typical design of a 35kV offshore wind turbine, segmented modeling is carried out. The maximum cut-off frequency of the lightning current is set to about 8.56MHz. Based on formula (2), the maximum segmented length is about 3.5m, and the offshore wind turbine lightning electromagnetic transient simulation model as Figure 2 shown is obtained.

[0088] Set , and The corresponding overvoltage insulation withstand capabilities are 675kV, 182kV, and 630kV respectively. The lightning current amplitudes corresponding to each return stroke order and , and the withstand levels, that is, the critical lightning currents, are shown in Table 3.

[0089] Table 3 Calculation results of the critical lightning current

[0090] ;

[0091] It should be noted that in Table 3, when the critical lightning current > 250 kA, in the subsequent calculation of the cumulative probability of lightning current, the corresponding cumulative probability is considered to be 1. Further, calculate the in formula (3), as shown in Table 4.

[0092] Table 4 Calculation results

[0093] ;

[0094] Based on Table 4 and combined with formula (3), obtain , , , as shown in Table 5.

[0095] Table 5 Calculation results

[0096] ;

[0097] Configure 5 lightning arrester schemes for the cable as Figure 3 shown (Scheme #1, Scheme #2, Scheme #3, Scheme #4, and Scheme #5). Under the same lightning current, the , , and maximum overvoltages on the cable are as Figure 4 shown. It can be seen that under different lightning arrester configuration schemes, , , and do not increase or decrease simultaneously. At this time, calculate the , , , and the results are shown in Table 6.

[0098] Table 6 5 lightning arrester schemes and the calculation results without configuration

[0099] ;

[0100] At this time, if the operator requires that , , and are all greater than 80%, then select Scheme #2; if the operator requires that , , and are all greater than 90%, then select Scheme #5. That is, the operator can select the configuration scheme according to its own risk preference.

[0101] At the same time, the cost can also be further considered according to formula (4). In this example, there are 36 wind turbines in a wind farm, with a floor area of approximately 30 km 2 , considering different lightning strike densities: 5 times / (km2 * times / year), 10 times / (km 2 * year), then in formula (4), correspond to 150 times / year and 300 times / year respectively; Take 10,000 yuan; is the cost of newly added lightning arresters under different lightning arrester configuration schemes, and each lightning arrester is taken as 800 yuan; is the transformation cost, and each wind turbine is taken as 20,000 yuan; is the depreciation rate, calculated according to the 5-year operation life of the lightning arrester, and taken as 0.2; is the operation and maintenance cost of the newly added lightning arrester, taken as 150 yuan per arrester per year. Then, under different lightning arrester configuration schemes, different corresponding to are shown in Table 7.

[0102] Table 7 Five lightning arrester schemes and two under Calculation results

[0103]

[0104] The scheme with W closer to 0 is the optimal scheme. In this embodiment, wind farms under two annual lightning strike frequencies of wind farms are considered. When taking 150, select Scheme #3; When taking 300, select Scheme #5; that is, the operator can select the optimal scheme according to the actual lightning activity situation and its related costs in the actual area where it is located.

[0105] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dynamic configuration method for arresters in an offshore wind farm based on multi-overvoltage collaborative suppression, characterized in that: It includes the following steps: S1. Based on the data of the lightning location system, obtain the statistical results of offshore lightning parameters; The statistical results of the offshore lightning parameters described in step S1 include the proportion of various return stroke orders and the lightning current amplitude distributions corresponding to the proportions of various return stroke orders respectively. Using the lightning current amplitude cumulative probability function in IEEE, fit the lightning current amplitudes corresponding to various return stroke orders to obtain the lightning current amplitude cumulative probability; Among them, each proportion of the strike sequence includes the proportion of positive single lightning strikes , the proportion of negative single lightning strikes , the proportion of positive first return strokes , the proportion of negative first return strokes , the proportion of positive subsequent return strokes , the proportion of negative subsequent return strokes ; Lightning current amplitude cumulative probability includes the cumulative probability of the lightning current amplitude of a single positive lightning strike , the cumulative probability of the lightning current amplitude of a single negative lightning strike , the cumulative probability of the lightning current amplitude of the first positive return stroke , the cumulative probability of the lightning current amplitude of the first negative return stroke , the cumulative probability of the lightning current amplitude of subsequent positive return strokes , the cumulative probability of the lightning current amplitude of subsequent negative return strokes ; The expression of the lightning current amplitude cumulative probability function is as follows: （1）； In the formula, represents the lightning current amplitude exceeding the critical lightning current probability; is the lightning current amplitude parameter; is the shape parameter; S2. Establish an electromagnetic transient simulation model of offshore wind turbine lightning strikes, and conduct lightning strike simulations under various return stroke orders to obtain the critical lightning current corresponding to the overvoltage insulation withstand level on the cable inside the offshore wind turbine; Step S2 specifically includes the following steps: S21. Use PSCAD electromagnetic transient simulation software to conduct segmented modeling to obtain an electromagnetic transient simulation model of offshore wind turbine lightning strikes: Establish a chain equivalent circuit for the lightning protection downlead of the offshore wind turbine blade, the moving contact part, the nacelle, the tower barrel, and the cable respectively; Model the lightning arrester and surge protector using nonlinear resistors; Model the transformer inside the nacelle using a high-frequency model; Use the ground capacitance to equivalent the high-frequency characteristics during the lightning strike of the switchgear at the bottom of the tower barrel; Use Comsol finite element software to calculate the coupling capacitance between the tower barrel and the cable armor layer, between the cable armor layer and the shielding layer, between the cable shielding layers, and between the cable shielding layer and the core wire; Use the Heidler function to simulate the lightning current waveform, and set the lightning current waveform corresponding to positive single lightning strike to 22 / 230 μs, the lightning current waveform corresponding to negative single lightning strike to 2.6 / 50 μs, the lightning current waveform corresponding to positive first return stroke to 10 / 350 μs, the lightning current waveform corresponding to negative first return stroke to 1 / 200 μs, and the lightning current waveforms corresponding to subsequent positive and negative return strokes to 0.25 / 100 μs; S22. Based on the lightning electromagnetic transient simulation model of an offshore wind turbine, lightning strikes are simulated under various lightning current waveforms to obtain the overvoltage between the tower barrel and the armor layer, the overvoltage between the armor layer and the shielding layer, and the overvoltage between the shielding layer and the core wire at the critical lightning current when the insulation withstand strength is reached; S3. Substitute the critical lightning current obtained in step S2 into the statistical results of the offshore lightning parameters obtained in step S1, and calculate the overvoltage withstand probability; S4. On the premise of considering the needs of the operator, evaluate the lightning protection effects of various lightning arrester configuration schemes based on the overvoltage withstand probability obtained in step S3, and obtain the optimal lightning arrester configuration scheme.

2. The dynamic configuration method of arrester for offshore wind farm based on multi-overvoltage collaborative suppression according to claim 1, wherein: In step S21, the segment length during modeling is set related to the maximum cut-off frequency of the lightning current: （2）； Wherein, is the upper limit cut-off frequency of lightning current, with the unit of MHz; is the speed of light.

3. The dynamic configuration method of arresters for offshore wind farms based on multi-overvoltage collaborative suppression according to claim 1, wherein: In step S3, the overvoltage withstand probability The calculation formula is as follows: （3）； Wherein, and in is overvoltage , or ; is the proportion of the th return stroke order; is the cumulative probability of lightning current amplitude obtained by substituting the critical lightning current corresponding to the proportion of the return stroke order into the cumulative probability function of lightning current amplitude.

4. The dynamic configuration method of arrester for offshore wind farm based on multi-overvoltage collaborative suppression according to claim 3, characterized in that: In step S4, based on , and corresponding overvoltage withstand probabilities , , , evaluate the lightning protection effect, and considering the operating costs of the operator, determine the optimal arrester configuration plan.

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