A method and device for simulating a lightning return current of a fan

Abstract

The application provides a wind turbine lightning stroke current simulation method and device, and relates to the technical field of lightning simulation. The method comprises the following steps: obtaining design data sets of a target wind turbine; performing characteristic impedance calculation according to the design data sets to obtain characteristic impedance sets, wherein the characteristic impedance sets comprise lightning return stroke channel characteristic impedance, tower section characteristic impedance and blade micro-element section characteristic impedance; performing transmission line construction according to the characteristic impedance sets to obtain transmission line sets, wherein the transmission line sets comprise a first transmission line, a second transmission line and a third transmission line; performing impedance discontinuity interface identification and current reflection coefficient calculation according to the transmission line sets to obtain current reflection coefficient sets; constructing a multi-section transmission line model according to the transmission line sets and the current reflection coefficient sets, setting a return stroke current source, inputting the return stroke current source into the multi-section transmission line model to perform current reflection coefficient correction, return stroke current time domain solving and return stroke current frequency domain correction, and obtaining a return stroke current simulation result.

Description

Technical Field

[0001] This application relates to the field of lightning strike simulation technology, and in particular to a method and apparatus for simulating the return stroke current of a lightning strike on a wind turbine. Background Technology

[0002] With the continuous increase in the single-unit capacity and tower height of wind turbine generators, the probability of wind turbines being struck by lightning has increased significantly. The return stroke current generated by lightning strikes is characterized by high amplitude, steep wavefront, and complex transient processes. Accurately simulating the propagation and distribution characteristics of the return stroke current in the wind turbine structure is a key prerequisite for conducting electromagnetic transient analysis of wind turbine lightning strikes, insulation coordination design, and optimization of lightning protection.

[0003] Existing methods for simulating lightning return current have incomplete modeling paths, neglecting the impedance characteristics of the blades and the lightning return current channel, and failing to fully depict the entire propagation process of the lightning current. The impedance discontinuity interface is poorly handled, and the static reflection coefficient is used, which makes it difficult to reflect the dynamic reflection behavior of the return current. Traditional time-domain solutions are unable to correct the phase shift introduced by the frequency-varying characteristics of the transmission line, resulting in insufficient accuracy in the simulation of return current and affecting the design of wind turbine insulation equipment. Summary of the Invention

[0004] To address the aforementioned problems, in a first aspect, the present invention provides a method for simulating the return stroke current of a wind turbine lightning strike, comprising: Obtain the design data set of the target wind turbine, which includes the geometric data of lightning return stroke channels, the geometric data of the wind turbine tower, the material property data, the geometric data of the wind turbine blades, and the electromagnetic property data. The characteristic impedance is calculated based on the design data set to obtain the characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section. Transmission lines are constructed based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line. Based on the transmission line set, impedance discontinuity interface identification and current reflection coefficient calculation are performed to obtain the current reflection coefficient set. A multi-segment transmission line model is constructed based on the transmission line set and the current reflection coefficient set. A return stroke current source is set, and the return stroke current source is input into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current to obtain the simulation results of return stroke current.

[0005] In one embodiment, characteristic impedance calculation based on a design dataset includes: Substitute the geometric data of the lightning return stroke channel into a preset height function to calculate the characteristic impedance of the lightning return stroke channel. The characteristic impedance of the tower section is calculated based on the geometric data and material property data of the wind turbine tower. The series inductance and parallel capacitance components are calculated based on the geometric and electromagnetic properties of the wind turbine blades. The characteristic impedance of the blade micro-segment is then calculated based on the series inductance and parallel capacitance components.

[0006] In one embodiment, constructing a transmission line based on a set of characteristic impedances includes: The first transmission line is constructed based on the characteristic impedance of the lightning return path. Based on the characteristic impedance of the tower section, a transmission line for the tower section is constructed, and all the transmission lines for the tower section are connected in series to form a second transmission line. Based on the characteristic impedance of the blade micro-segment, a transmission line for the blade micro-segment is constructed, and all the transmission lines for the blade micro-segment are connected in series to form a third transmission line.

[0007] In one embodiment, impedance discontinuity interface identification and current reflection coefficient calculation are performed based on the transmission line set to obtain a current reflection coefficient set, including: The connection points between the first and second transmission lines, the connection points between the second and third transmission lines, and the grounding point at the bottom of the second transmission line are defined as impedance discontinuity interfaces. Based on the traveling wave direction and the characteristic impedance set, determine the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface. The current reflection coefficient corresponding to the impedance discontinuity interface is calculated based on the incident characteristic impedance and the transmission characteristic impedance. The set of current reflection coefficients is composed of the current reflection coefficients corresponding to each impedance discontinuity interface.

[0008] In one embodiment, determining the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface based on the traveling wave direction and the characteristic impedance set includes: The traveling wave direction includes upward and downward. At the connection between the first transmission line and the second transmission line, the incident characteristic impedance is the characteristic impedance of the tower section when traveling upward, and the transmission characteristic impedance is the characteristic impedance of the lightning return stroke channel; when traveling downward, the incident characteristic impedance is the characteristic impedance of the lightning return stroke channel, and the transmission characteristic impedance is the characteristic impedance of the tower section. At the connection between the second and third transmission lines, the incident characteristic impedance is the characteristic impedance of the blade micro-element segment when going up, and the transmission characteristic impedance is the characteristic impedance of the tower segment when going down; the incident characteristic impedance is the characteristic impedance of the tower segment when going down, and the transmission characteristic impedance is the characteristic impedance of the blade micro-element segment. For the bottom grounding point of the second transmission line, the incident characteristic impedance is the grounding impedance during uplink and the transmission characteristic impedance is the tower section characteristic impedance; during downlink, the incident characteristic impedance is the tower section characteristic impedance and the transmission characteristic impedance is the grounding impedance.

[0009] In one embodiment, a multi-segment transmission line model is constructed based on the transmission line set and the current reflection coefficient set, including: The first transmission line, the second transmission line, and the third transmission line are connected in series and coupled in the order of the physical connection of the target wind turbine to form a multi-segment transmission line topology. By configuring each current reflection coefficient in the set of current reflection coefficients at the corresponding impedance discontinuity interface of the multi-segment transmission line topology, a multi-segment transmission line model is obtained.

[0010] In one embodiment, a return stroke current source is set up, and the return stroke current source is input into a multi-segment transmission line model for current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current to obtain the simulation results of return stroke current, including: A return stroke current source is constructed based on the standard lightning current waveform parameters. The return stroke current source is injected from the bottom position of the first transmission line in the multi-segment transmission line model to excite a traveling wave. Based on the current arrival height of the traveling wave in the first transmission line, the current reflection coefficients corresponding to each impedance discontinuity interface in the current reflection coefficient set are corrected to obtain the dynamic current reflection coefficient set. Using a time-domain solution algorithm based on traveling wave propagation theory, all propagation paths of the traveling wave in the multi-segment transmission line model are traced along the first transmission line (upward), the second transmission line (downward), and the third transmission line (downward). The instantaneous value of the initial return stroke current, the amplitude attenuation factor, and the cumulative propagation delay corresponding to each propagation path are calculated based on the dynamic current reflection coefficient set. The instantaneous value of the initial return stroke current is converted to the frequency domain to obtain the initial frequency component; the initial frequency component is compensated for phase error to obtain the corrected frequency component; the corrected frequency component is converted back to the time domain to obtain the corrected instantaneous value of the return stroke current. The spatiotemporal domain of the multi-segment transmission line model is established. Based on the amplitude attenuation factor and cumulative propagation delay, the instantaneous value of the corrected return stroke current is assigned in the spatiotemporal domain to obtain the simulation results of the return stroke current.

[0011] Secondly, the present invention provides a wind turbine lightning return stroke current simulation device for implementing the aforementioned wind turbine lightning return stroke current simulation method, the device comprising: The design data set acquisition module is used to acquire the design data set of the target wind turbine. The design data set includes the geometric data of lightning return stroke channels, the geometric data of the wind turbine tower, the material property data, the geometric data of the wind turbine blades, and the electromagnetic property data. The characteristic impedance set acquisition module is used to calculate the characteristic impedance based on the design data set and obtain the characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section. The transmission line set acquisition module is used to construct transmission lines based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line. The current reflection coefficient set acquisition module is used to identify impedance discontinuity interfaces and calculate current reflection coefficients based on the transmission line set, thereby obtaining the current reflection coefficient set. The return stroke current simulation result acquisition module is used to construct a multi-segment transmission line model based on the transmission line set and the current reflection coefficient set, set the return stroke current source, input the return stroke current source into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current and frequency-domain correction of return stroke current, and obtain the return stroke current simulation result.

[0012] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the wind turbine lightning return current simulation method.

[0013] Fourthly, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the wind turbine lightning strike return current simulation method.

[0014] The present invention has the following beneficial effects: 1. By incorporating the lightning return stroke channel, wind turbine tower, and wind turbine blades into the transmission line modeling scope, a transmission line set covering the entire propagation path of lightning current is constructed, fully depicting the physical process of the return stroke current being injected from the bottom of the channel to the grounding device and the blade tip. Based on the transmission line set, impedance discontinuity interface identification and current reflection coefficient calculation are performed, accurately capturing the transient physical process of lightning current development. Based on the transmission line set and the current reflection coefficient set, a multi-segment transmission line model is constructed, and current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current are performed through the multi-segment transmission line model. This accurately reflects the dynamic reflection behavior of return stroke current when simulating traveling wave propagation, and corrects the phase shift introduced by the frequency-varying characteristics of the transmission line, significantly improving the accuracy of return stroke current simulation.

[0015] 2. Based on the geometric and material properties of each component of the wind turbine, the characteristic impedances of the lightning channel, tower, and blades were calculated separately. The variation of channel impedance with height, the variable cross-section effect of the tower, and the non-uniform geometric characteristics of the blades were fully considered, ensuring the physical accuracy of the transmission line electrical parameters from the source. Based on the difference in characteristic impedance, the first, second, and third transmission lines were constructed and connected in series, transforming the complex wind turbine-lightning coupling system into an analytical multi-segment transmission line network topology, providing a structured model foundation for the discretized tracing of the traveling wave propagation path. By identifying three impedance discontinuities and calculating the direction-dependent current reflection coefficients, the reflection and refraction behavior of the traveling wave at the physical connection nodes was accurately quantified. This enabled subsequent traveling wave tracing and current superposition calculations to truly reflect the multiple reflections, transmissions, and energy attenuation processes of the lightning current in the wind turbine structure, significantly improving the model's ability to simulate the oscillation characteristics and spatial distribution details of high-frequency transient waveforms.

[0016] 3. Multiple transmission line segments are coupled according to their actual physical connection sequence, and current reflection coefficients are configured at impedance discontinuities to form a multi-segment transmission line model that strictly corresponds to the actual wind turbine structure. After the return stroke current is injected, the reflection coefficients are corrected in real time based on the height of the traveling wave front, enabling the model to dynamically reflect the unsteady impedance changes during the development of the lightning current, significantly improving the simulation realism of the return stroke waveform front and oscillation characteristics. A hybrid solution strategy combining time-domain traveling wave tracing and frequency-domain phase error compensation is adopted, which not only fully records the amplitude attenuation factor and cumulative propagation delay of each propagation path, but also effectively corrects the phase shift introduced by the frequency-varying characteristics of the transmission line, making up for the insufficient accuracy of high-frequency components in pure time-domain algorithms and ensuring the calculation accuracy over a wide frequency range. By constructing a spatiotemporal domain, the corrected instantaneous values ​​of the return stroke current are superimposed and assigned in spatial and time coordinates, ultimately obtaining the lightning current distribution results at any location and time of the wind turbine structure, further improving the accuracy of the return stroke current simulation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a structural diagram of the device according to an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0020] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0021] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0022] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Reference Figure 1 This invention provides a method for simulating the return stroke current of a wind turbine struck by lightning, comprising: S100 acquires the design data set of the target wind turbine, which includes the geometric data of the lightning return path, the geometric data of the wind turbine tower, the material property data, the geometric data of the wind turbine blades, and the electromagnetic property data.

[0024] In some embodiments, the design data set of the target wind turbine can be obtained by reading the design drawing parameters, 3D model data, material specification files or electromagnetic simulation model files pre-stored in the target wind turbine.

[0025] The geometric data of the lightning return stroke channel should include at least the bottom radius of the lightning return stroke channel. The function type identifier related to channel height. The bottom radius of the channel. Used to determine the reference characteristic impedance at the bottom of the lightning return stroke channel, the height correlation function type identifier is used to determine the calculation method of the height correction factor.

[0026] The geometric data of the wind turbine tower includes the length of each tower segment after the target wind turbine tower is divided along the height direction. Equivalent radius of the outer wall of the tower Equivalent radius of the inner wall of the tower subscript The tower section is numbered; material property data includes the relative magnetic permeability of the tower material. .

[0027] Wind turbine blade geometry data includes the lengths of each blade micro-segment after discretization along the span. equivalent radius of blade micro-segment and the distance from the reference potential surface subscript The data refers to the numbering of the blade's micro-segments; the electromagnetic property data includes the relative permeability of the blade material. and relative permittivity .

[0028] S200 calculates characteristic impedance based on the design data set to obtain a characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section.

[0029] In some embodiments, characteristic impedance calculation based on a design dataset includes: Substitute the geometric data of the lightning return stroke channel into a preset height function to calculate the characteristic impedance of the lightning return stroke channel. The characteristic impedance of the tower section is calculated based on the geometric data and material property data of the wind turbine tower. The series inductance and parallel capacitance components are calculated based on the geometric and electromagnetic properties of the wind turbine blades. The characteristic impedance of the blade micro-segment is then calculated based on the series inductance and parallel capacitance components.

[0030] In some embodiments, a preset height function is used to describe the characteristic impedance of the lightning return stroke channel as a function of height. The changing pattern of the height function is predefined as follows: In the formula: For height Characteristic impedance of the lightning return path at the location; The reference characteristic impedance at the bottom of the channel is taken as an empirical constant or determined by the radius of the bottom of the channel. Sure; This is a high correction factor; For highly correlated functions, linear functions can be selected. Or in the form of an exponential decay function, etc.

[0031] By substituting the radius parameter from the lightning return stroke channel geometry into the aforementioned preset height function, the characteristic impedance of the lightning return stroke channel can be calculated. .

[0032] The characteristic impedance of the tower section was calculated based on the geometric and material property data of the wind turbine tower. The calculation formula is: In the formula: The vacuum permeability; It is the vacuum permittivity; The equivalent radius of the inner wall of the tower is zero or a skin depth correction value when the tower is a solid structure.

[0033] Series inductance component and parallel capacitor components It can be calculated using the following formula: In the formula: The distance to the reference potential surface is usually taken as the distance from the ground plane or infinity.

[0034] Then, the characteristic impedance of the blade micro-element is calculated based on the series inductance component and the parallel capacitance component. The calculation formula is as follows: The calculated characteristic impedances of the lightning return stroke channel, each tower section, and each blade micro-element section are combined to form a characteristic impedance set, providing basic parameters for subsequent transmission line construction.

[0035] S300 constructs transmission lines based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line.

[0036] In some embodiments, transmission line construction is performed based on a set of characteristic impedances, including: The first transmission line is constructed based on the characteristic impedance of the lightning return path. Based on the characteristic impedance of the tower section, a transmission line for the tower section is constructed, and all the transmission lines for the tower section are connected in series to form a second transmission line. Based on the characteristic impedance of the blade micro-segment, a transmission line for the blade micro-segment is constructed, and all the transmission lines for the blade micro-segment are connected in series to form a third transmission line.

[0037] The lightning return stroke channel is discretized along the height direction into several uniform or non-uniform transmission line segments. Each transmission line segment is characterized by its corresponding lightning return stroke channel characteristic impedance. Parameters are assigned to form the first transmission line. The first transmission line is used to simulate the propagation path of lightning current from the bottom of the return stroke channel upwards.

[0038] The transmission line is constructed using each tower section as a unit, and each tower section transmission line has a uniform characteristic impedance. and corresponding length All tower section transmission lines are connected in series according to the actual physical connection sequence of the target wind turbine tower from top to bottom. That is, the output end of the first tower section transmission line is connected to the input end of the second tower section transmission line, and so on, to form a complete second transmission line. The second transmission line is used to simulate the process of lightning current propagating downwards along the tower.

[0039] A blade micro-element transmission line is constructed using each blade micro-element as a unit, and each blade micro-element transmission line has a uniform blade micro-element characteristic impedance. and the corresponding infinitesimal length All blade micro-segment transmission lines are connected in series according to the actual geometric orientation of the blade to form a third transmission line. This third transmission line is used to simulate the process of lightning current propagating from the flashover point along the blade to the blade root.

[0040] The transmission line set consists of a first transmission line, a second transmission line, and a third transmission line. The first transmission line corresponds to the lightning return stroke channel, the second transmission line corresponds to the wind turbine tower, and the third transmission line corresponds to the wind turbine blade. The basic electrical parameter models of each transmission line follow the uniform transmission line equation: In the formula: For transmission line location At any time The voltage; For transmission line location At any time The current; The inductance per unit length of the transmission line; Capacitance per unit length of the transmission line.

[0041] Through the above construction process, a set of transmission lines corresponding to the actual physical structure of the wind turbine was obtained, providing a structured foundation for subsequent impedance discontinuity interface identification and multi-segment transmission line model establishment.

[0042] S400 performs impedance discontinuity interface identification and current reflection coefficient calculation based on the transmission line set to obtain the current reflection coefficient set. In some embodiments, impedance discontinuity interface identification and current reflection coefficient calculation are performed based on the transmission line set to obtain a current reflection coefficient set, including: The connection points between the first and second transmission lines, the connection points between the second and third transmission lines, and the grounding point at the bottom of the second transmission line are defined as impedance discontinuity interfaces. Based on the traveling wave direction and the characteristic impedance set, determine the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface. The current reflection coefficient corresponding to the impedance discontinuity interface is calculated based on the incident characteristic impedance and the transmission characteristic impedance. The set of current reflection coefficients is composed of the current reflection coefficients corresponding to each impedance discontinuity interface.

[0043] In some embodiments, the impedance discontinuity interface is the location where the characteristic impedance of the transmission line changes abruptly. The connection point between the first and second transmission lines is identified as the first impedance discontinuity interface, located at the electrical connection point between the bottom of the lightning return path and the top of the tower. The connection point between the second and third transmission lines is identified as the second impedance discontinuity interface, located at the electrical connection point between the top of the tower and the blade root. The bottom grounding point of the second transmission line is identified as the third impedance discontinuity interface, located at the connection point between the bottom of the tower and the grounding device.

[0044] In some embodiments, determining the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface based on the traveling wave direction and the characteristic impedance set includes: The traveling wave direction includes upward and downward. At the connection between the first transmission line and the second transmission line, the incident characteristic impedance is the characteristic impedance of the tower section when traveling upward, and the transmission characteristic impedance is the characteristic impedance of the lightning return stroke channel; when traveling downward, the incident characteristic impedance is the characteristic impedance of the lightning return stroke channel, and the transmission characteristic impedance is the characteristic impedance of the tower section. At the connection between the second and third transmission lines, the incident characteristic impedance is the characteristic impedance of the blade micro-element segment when going up, and the transmission characteristic impedance is the characteristic impedance of the tower segment when going down; the incident characteristic impedance is the characteristic impedance of the tower segment when going down, and the transmission characteristic impedance is the characteristic impedance of the blade micro-element segment. For the bottom grounding point of the second transmission line, the incident characteristic impedance is the grounding impedance during uplink and the transmission characteristic impedance is the tower section characteristic impedance; during downlink, the incident characteristic impedance is the tower section characteristic impedance and the transmission characteristic impedance is the grounding impedance.

[0045] In some embodiments, the upward direction is defined as the direction in which the current traveling wave propagates from the ground reference surface to the top of the lightning return path, and the downward direction is defined as the direction in which the current traveling wave propagates from the top of the lightning return path to the ground reference surface.

[0046] For the connection between the first and second transmission lines: when the traveling wave direction is upward, the incident characteristic impedance is taken as the characteristic impedance of the tower section adjacent to the connection point in the second transmission line, denoted as... The transmission characteristic impedance is taken as the characteristic impedance of the lightning return stroke channel adjacent to the connection point in the first transmission line, denoted as . When the traveling wave direction is downward, the incident characteristic impedance is taken as... Transmission characteristic impedance is taken .

[0047] For the connection between the second and third transmission lines: when the traveling wave direction is upward, the incident characteristic impedance is taken as the characteristic impedance of the blade micro-element segment adjacent to the connection point in the third transmission line, denoted as... The transmission characteristic impedance is taken as the characteristic impedance of the tower section adjacent to the connection point in the second transmission line, denoted as... When the traveling wave direction is downward, the incident characteristic impedance is taken as... Transmission characteristic impedance is taken .

[0048] For the bottom grounding point of the second transmission line: when the traveling wave direction is upward, the incident characteristic impedance is taken as the grounding impedance, denoted as... The transmission characteristic impedance is taken as the characteristic impedance of the tower section adjacent to the bottom in the second transmission line, denoted as... When the traveling wave direction is downward, the incident characteristic impedance is taken as... Transmission characteristic impedance is taken .

[0049] In some embodiments, the current reflection coefficient corresponding to the impedance discontinuity interface is calculated based on the incident characteristic impedance and the transmission characteristic impedance. The calculation formula is: In the formula: This is the incident characteristic impedance, which is the characteristic impedance of the transmission line in the direction of the traveling wave. It is the transmission characteristic impedance, that is, the characteristic impedance of the transmission line into which the traveling wave is transmitted.

[0050] The current reflection coefficient at the connection between the second and third transmission lines can be calculated using the above formula. and , corresponding to the uplink and downlink traveling wave directions respectively; the current reflection coefficient at the connection between the first transmission line and the second transmission line. and These correspond to the upward and downward directions of the traveling wave, respectively. Current reflection coefficient at the bottom ground point of the second transmission line and These correspond to the upward and downward traveling wave directions, respectively; the set of current reflection coefficients is composed of the current reflection coefficients corresponding to each impedance discontinuity interface.

[0051] S500 constructs a multi-segment transmission line model based on the transmission line set and the current reflection coefficient set, sets a return stroke current source, inputs the return stroke current source into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current, and obtains the return stroke current simulation results.

[0052] In some embodiments, a multi-segment transmission line model is constructed based on the transmission line set and the current reflection coefficient set, including: The first transmission line, the second transmission line, and the third transmission line are connected in series and coupled in the order of the physical connection of the target wind turbine to form a multi-segment transmission line topology. By configuring each current reflection coefficient in the set of current reflection coefficients at the corresponding impedance discontinuity interface of the multi-segment transmission line topology, a multi-segment transmission line model is obtained.

[0053] In some embodiments, the first transmission line corresponds to the lightning return stroke channel, with its top being the top of the lightning return stroke channel and its bottom being the connection end between the lightning return stroke channel and the tower. The second transmission line corresponds to the wind turbine tower, with its top being the connection end between the tower and the lightning return stroke channel and its bottom being the connection end between the tower and the grounding device. The third transmission line corresponds to the wind turbine blade, with its blade root end being the connection end between the blade and the tower and its blade tip being the free end of the blade.

[0054] The specific series connection order of the multi-segment transmission line topology is as follows: the root end of the third transmission line is connected to the top of the second transmission line, and the bottom of the second transmission line is connected to the bottom of the first transmission line. The connection nodes are defined as follows: node A connects the third transmission line to the second transmission line; node B connects the second transmission line to the first transmission line; and node G connects the bottom of the second transmission line to the grounding device.

[0055] This results in a multi-segment transmission line topology, consisting of transmission lines in the blade micro-element segment, transmission lines in the tower segment, and transmission lines in the lightning return stroke channel, connected in series. In this topology, the characteristic impedance of the transmission lines abruptly changes at nodes A, B, and G, forming impedance discontinuities.

[0056] Configure the current reflection coefficient at node A. and Configure the current reflection coefficient at node B. and Configure the current reflection coefficient at node G. and .

[0057] By configuring the aforementioned current reflection coefficients in the boundary conditions at the corresponding nodes and combining them with the transmission line equations for each segment, a complete multi-segment transmission line model is obtained. This model can describe the reflection and transmission behavior of lightning current return stroke traveling waves as they propagate between the lightning return stroke channel, wind turbine tower, and wind turbine blades.

[0058] In some embodiments, a return stroke current source is set up, and the return stroke current source is input into a multi-segment transmission line model for current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current to obtain return stroke current simulation results, including: A return stroke current source is constructed based on the standard lightning current waveform parameters. The return stroke current source is injected from the bottom position of the first transmission line in the multi-segment transmission line model to excite a traveling wave. Based on the current arrival height of the traveling wave in the first transmission line, the current reflection coefficients corresponding to each impedance discontinuity interface in the current reflection coefficient set are corrected to obtain the dynamic current reflection coefficient set. Using a time-domain solution algorithm based on traveling wave propagation theory, all propagation paths of the traveling wave in the multi-segment transmission line model are traced along the first transmission line (upward), the second transmission line (downward), and the third transmission line (downward). The instantaneous value of the initial return stroke current, the amplitude attenuation factor, and the cumulative propagation delay corresponding to each propagation path are calculated based on the dynamic current reflection coefficient set. The instantaneous value of the initial return stroke current is converted to the frequency domain to obtain the initial frequency component; the initial frequency component is compensated for phase error to obtain the corrected frequency component; the corrected frequency component is converted back to the time domain to obtain the corrected instantaneous value of the return stroke current. The spatiotemporal domain of the multi-segment transmission line model is established. Based on the amplitude attenuation factor and cumulative propagation delay, the instantaneous value of the corrected return stroke current is assigned in the spatiotemporal domain to obtain the simulation results of the return stroke current.

[0059] In some embodiments, standard lightning current waveform parameters include peak current. Wavefront time and half-peak time The return stroke current source is represented by a double exponential function: In the formula: To return the current source at time The instantaneous value; This refers to the waveform correction coefficient; and These are the wave tail attenuation coefficient and the wave front rise coefficient, respectively, based on the wave front time. and half-peak time Sure.

[0060] The return current source is injected from the bottom position of the first transmission line in the multi-segment transmission line model, with the injection position corresponding to the height coordinate in the first transmission line. At this point, the injection of a return current source excites a traveling wave in the transmission line, which propagates upwards from the bottom along the first transmission line.

[0061] As the leading edge of the traveling wave propagates upward in the first transmission line, the current altitude reached... As the lightning return path adjacent to the bottom of the first transmission line changes, the characteristic impedance value also changes. The static characteristic impedance is replaced with the dynamic characteristic impedance value corresponding to the current arrival height, thereby updating the current reflection coefficient corresponding to each impedance discontinuity interface.

[0062] At the connection between the updated first and second transmission lines, the downlink dynamic current reflection coefficient The expression is: In the formula: For height Characteristic impedance of the lightning return path at the location; superscript This represents a dynamic value.

[0063] The reflection coefficient corrections for the other interfaces follow the same principle, ultimately forming a set of dynamic current reflection coefficients related to the current traveling wave position.

[0064] The traveling wave travels from the injection point along the first transmission line to node B, where it is reflected and transmitted. The reflected wave travels along the first transmission line, and the transmitted wave enters the second transmission line and travels along the second transmission line to node G, where it is reflected and transmitted again. The reflected wave travels along the second transmission line, while the traveling wave is transmitted to the third transmission line at node A and propagates along the third transmission line. All possible combinations of reflection and transmission paths are tracked and recorded.

[0065] For the The propagation path is calculated based on the dynamic current reflection coefficient set to obtain the corresponding instantaneous value of the initial return stroke current. Amplitude attenuation factor and cumulative propagation delay .

[0066] The initial return stroke current instantaneous value is the current value at the path start point: The amplitude attenuation factor is the product of the attenuation of each transmission line segment along the path and the transmission and reflection coefficients at each interface: In the formula: For the path passing through the first Current transmission coefficient at an impedance discontinuity interface; For the path passing through the first Dynamic current reflection coefficient of an impedance discontinuity interface; For the first The attenuation constant of a segment transmission line; In the first The propagation distance in a transmission line segment.

[0067] The cumulative propagation delay is the sum of the times required for the path to propagate through each segment of the transmission line: In the formula: For the traveling wave in the 1st The propagation speed in a transmission line is determined by the inductance per unit length of the transmission line. and capacitance per unit length Decide, .

[0068] The instantaneous values ​​of the initial return stroke current corresponding to each propagation path The initial frequency components are obtained by converting the data to the frequency domain using Fourier transform. ,in ω is the angular frequency.

[0069] Phase error compensation is applied to the initial frequency components to compensate for the phase shift caused by the frequency correlation of the transmission line distributed parameters. The phase error compensation factor is... ,in The phase compensation function is determined by the transmission line frequency-varying characteristic parameters, and the correction frequency component is given by the following formula:

[0070] The corrected frequency component is converted back to the time domain using an inverse Fourier transform to obtain the instantaneous value of the corrected return stroke current. .

[0071] Establish the spatiotemporal domain of a multi-segment transmission line model, where the spatiotemporal domain consists of spatial coordinates. and time coordinates Zhang Cheng. Spatial coordinates Covering the total length range of the first, second, and third transmission lines, time coordinates The duration of the lightning current return stroke process.

[0072] Based on amplitude attenuation factor and cumulative propagation delay The instantaneous value of the corrected return stroke current will be... Assigning values ​​within the space-time domain, for positions in the space-time domain At any time The current value is obtained by superimposing all the traveling wave components that arrive at that position and time: In the formula: For at any time Able to reach the location The set of all propagation path numbers; For the first The propagation path reaches the location Required propagation delay.

[0073] After the above steps, the simulation results of the return stroke current are finally obtained. These results include the distribution of lightning return stroke current at any location and time in the spatiotemporal domain of the multi-segment transmission line model, which can completely describe the propagation, reflection and attenuation process of lightning current in the wind turbine structure.

[0074] Reference Figure 2 This invention provides a wind turbine lightning return stroke current simulation device 20, used to implement a method for simulating wind turbine lightning return stroke current. The device includes: The design data set acquisition module 21 is used to acquire the design data set of the target wind turbine. The design data set includes lightning return stroke channel geometry data, wind turbine tower geometry data, material property data, wind turbine blade geometry data, and electromagnetic property data. The characteristic impedance set acquisition module 22 is used to calculate the characteristic impedance based on the design data set and obtain the characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section. The transmission line set acquisition module 23 is used to construct transmission lines based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line. The current reflection coefficient set acquisition module 24 is used to identify impedance discontinuity interfaces and calculate current reflection coefficients based on the transmission line set to obtain the current reflection coefficient set. The return stroke current simulation result acquisition module 25 is used to construct a multi-segment transmission line model based on the transmission line set and the current reflection coefficient set, set the return stroke current source, input the return stroke current source into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current and frequency-domain correction of return stroke current, and obtain the return stroke current simulation result.

[0075] This application provides an electronic device, including a processor and a memory; the memory stores a computer program, wherein the computer program, when executed by the processor, implements the wind turbine lightning return current simulation method of any of the above schemes.

[0076] Specifically, the processor may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor may also include onboard memory for caching purposes. The processor may be a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of this application.

[0077] Memory can be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, memory can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, instruments, or propagation media. Specific examples of memory include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); and also random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0078] This application also provides a computer-readable medium storing a computer program that, when executed by a processor, implements the wind turbine lightning return current simulation method of any of the above-described schemes. This computer-readable medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into that device / apparatus / system. The aforementioned computer-readable medium carries one or more programs, which, when executed, implement the method as described in the embodiments of this application.

[0079] According to embodiments of this application, a computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency signals, etc., or any suitable combination thereof.

[0080] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for simulating the return stroke current of a wind turbine struck by lightning, characterized in that, include: Obtain the design data set of the target wind turbine, which includes the geometric data of lightning return stroke channels, the geometric data of the wind turbine tower, the material property data, the geometric data of the wind turbine blades, and the electromagnetic property data. The characteristic impedance is calculated based on the design data set to obtain the characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section. Transmission lines are constructed based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line. Based on the transmission line set, impedance discontinuity interface identification and current reflection coefficient calculation are performed to obtain the current reflection coefficient set. A multi-segment transmission line model is constructed based on the transmission line set and the current reflection coefficient set. A return stroke current source is set, and the return stroke current source is input into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current to obtain the simulation results of return stroke current.

2. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 1, characterized in that, Calculate the characteristic impedance based on the design data set, including: Substitute the geometric data of the lightning return stroke channel into a preset height function to calculate the characteristic impedance of the lightning return stroke channel. The characteristic impedance of the tower section is calculated based on the geometric data and material property data of the wind turbine tower. The series inductance and parallel capacitance components are calculated based on the geometric and electromagnetic properties of the wind turbine blades. The characteristic impedance of the blade micro-segment is then calculated based on the series inductance and parallel capacitance components.

3. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 1, characterized in that, Transmission line construction based on characteristic impedance set includes: The first transmission line is constructed based on the characteristic impedance of the lightning return path. Based on the characteristic impedance of the tower section, a transmission line for the tower section is constructed, and all the transmission lines for the tower section are connected in series to form a second transmission line. Based on the characteristic impedance of the blade micro-segment, a transmission line for the blade micro-segment is constructed, and all the transmission lines for the blade micro-segment are connected in series to form a third transmission line.

4. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 1, characterized in that, Based on the transmission line set, impedance discontinuity interface identification and current reflection coefficient calculation are performed to obtain the current reflection coefficient set, including: The connection points between the first and second transmission lines, the connection points between the second and third transmission lines, and the grounding point at the bottom of the second transmission line are defined as impedance discontinuity interfaces. Based on the traveling wave direction and the characteristic impedance set, determine the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface. The current reflection coefficient corresponding to the impedance discontinuity interface is calculated based on the incident characteristic impedance and the transmission characteristic impedance. The set of current reflection coefficients is composed of the current reflection coefficients corresponding to each impedance discontinuity interface.

5. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 4, characterized in that, Based on the traveling wave direction and the characteristic impedance set, determine the incident characteristic impedance and transmission characteristic impedance of the impedance discontinuity interface, including: The traveling wave direction includes upward and downward. At the connection between the first transmission line and the second transmission line, the incident characteristic impedance is the characteristic impedance of the tower section when traveling upward, and the transmission characteristic impedance is the characteristic impedance of the lightning return stroke channel; when traveling downward, the incident characteristic impedance is the characteristic impedance of the lightning return stroke channel, and the transmission characteristic impedance is the characteristic impedance of the tower section. At the connection between the second and third transmission lines, the incident characteristic impedance is the characteristic impedance of the blade micro-element segment when going up, and the transmission characteristic impedance is the characteristic impedance of the tower segment when going down; the incident characteristic impedance is the characteristic impedance of the tower segment when going down, and the transmission characteristic impedance is the characteristic impedance of the blade micro-element segment. For the bottom grounding point of the second transmission line, the incident characteristic impedance is the grounding impedance during uplink and the transmission characteristic impedance is the tower section characteristic impedance; during downlink, the incident characteristic impedance is the tower section characteristic impedance and the transmission characteristic impedance is the grounding impedance.

6. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 1, characterized in that, A multi-segment transmission line model is constructed based on the transmission line set and the current reflection coefficient set, including: The first transmission line, the second transmission line, and the third transmission line are connected in series and coupled in the order of the physical connection of the target wind turbine to form a multi-segment transmission line topology. By configuring each current reflection coefficient in the set of current reflection coefficients at the corresponding impedance discontinuity interface of the multi-segment transmission line topology, a multi-segment transmission line model is obtained.

7. The method for simulating the return stroke current of a wind turbine lightning strike according to claim 1, characterized in that, A return stroke current source is set up, and the return stroke current source is input into a multi-segment transmission line model for current reflection coefficient correction, time-domain solution of return stroke current, and frequency-domain correction of return stroke current to obtain the simulation results of return stroke current, including: A return stroke current source is constructed based on the standard lightning current waveform parameters. The return stroke current source is injected from the bottom position of the first transmission line in the multi-segment transmission line model to excite a traveling wave. Based on the current arrival height of the traveling wave in the first transmission line, the current reflection coefficients corresponding to each impedance discontinuity interface in the current reflection coefficient set are corrected to obtain the dynamic current reflection coefficient set. Using a time-domain solution algorithm based on traveling wave propagation theory, all propagation paths of the traveling wave in the multi-segment transmission line model are traced along the first transmission line (upward), the second transmission line (downward), and the third transmission line (downward). The instantaneous value of the initial return stroke current, the amplitude attenuation factor, and the cumulative propagation delay corresponding to each propagation path are calculated based on the dynamic current reflection coefficient set. The instantaneous value of the initial return stroke current is converted to the frequency domain to obtain the initial frequency component; the initial frequency component is compensated for phase error to obtain the corrected frequency component; the corrected frequency component is converted back to the time domain to obtain the corrected instantaneous value of the return stroke current. The spatiotemporal domain of the multi-segment transmission line model is established. Based on the amplitude attenuation factor and cumulative propagation delay, the instantaneous value of the corrected return stroke current is assigned in the spatiotemporal domain to obtain the simulation results of the return stroke current.

8. A device for simulating the return stroke current of a wind turbine lightning strike, used to implement the method for simulating the return stroke current of a wind turbine lightning strike as described in any one of claims 1 to 7, characterized in that, The device includes: The design data set acquisition module is used to acquire the design data set of the target wind turbine. The design data set includes the geometric data of lightning return stroke channels, the geometric data of the wind turbine tower, the material property data, the geometric data of the wind turbine blades, and the electromagnetic property data. The characteristic impedance set acquisition module is used to calculate the characteristic impedance based on the design data set and obtain the characteristic impedance set, which includes the characteristic impedance of the lightning return stroke channel, the characteristic impedance of the tower section, and the characteristic impedance of the blade micro-element section. The transmission line set acquisition module is used to construct transmission lines based on the characteristic impedance set to obtain a transmission line set, which includes a first transmission line, a second transmission line, and a third transmission line. The current reflection coefficient set acquisition module is used to identify impedance discontinuity interfaces and calculate current reflection coefficients based on the transmission line set, thereby obtaining the current reflection coefficient set. The return stroke current simulation result acquisition module is used to construct a multi-segment transmission line model based on the transmission line set and the current reflection coefficient set, set the return stroke current source, input the return stroke current source into the multi-segment transmission line model to perform current reflection coefficient correction, time-domain solution of return stroke current and frequency-domain correction of return stroke current, and obtain the return stroke current simulation result.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the wind turbine lightning return stroke current simulation method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the wind turbine lightning strike return current simulation method as described in any one of claims 1 to 7.

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