Lightning simulation method for fan blade and electronic equipment

Abstract

The invention provides a thunder and lightning simulation method for a fan blade and electronic equipment, and the method comprises the steps: determining a plurality of target frequencies in a preset frequency interval, obtaining a thunder and lightning current frequency spectrum through calculation according to a thunder and lightning current function, inputting a steady-state voltage into a structure model of the fan blade to obtain a simulation voltage frequency spectrum, and carrying out the simulation of the simulation voltage frequency spectrum. Generating a first current corresponding to a target frequency according to the lightning current frequency spectrum, generating a first impedance corresponding to the target frequency according to the simulation voltage frequency spectrum, performing time domain conversion on a lightning voltage frequency spectrum obtained based on the first current and the first impedance to obtain lightning voltage data, and inputting the lightning voltage data into a structure model of the fan blade, the calculation complexity is reduced through a specific frequency selection and calculation method, meanwhile, the potential distribution of each layer plate of the blade under the lightning impulse can be simulated more accurately by converting the lightning current data into the lightning voltage data and inputting the lightning voltage data into the structural model of the fan blade, and the lightning simulation result of the fan blade is obtained. And a more accurate lightning protection design basis is provided for the fan blade.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lightning protection for wind turbine blades, and in particular to a lightning simulation method and electronic equipment for wind turbine blades. Background Art

[0002] As wind turbine capacity increases, wind turbine hub height and blade diameter are also increasing, which further increases the probability of lightning strikes on wind turbine blades. In order to output higher rated power, wind turbines require longer blades. In order to meet these requirements and keep weight low, wind turbine manufacturers apply reinforced polymer materials such as carbon fiber to wind turbine blades. However, due to the poor conductivity of these materials, it also brings additional challenges to protecting blades from lightning strikes.

[0003] Traditional lightning simulation methods usually apply lightning current directly to the structural model of the blade. However, with the increase in the capacity of wind turbines, the diameter of the blades is also expanding. Directly applying lightning current to the structural model of the blades is likely to cause the calculation to not converge, resulting in a long calculation time. In addition, with the application of carbon fiber composite materials in wind turbine blades, it is also difficult for traditional lightning simulation methods to accurately simulate the current distribution of wind turbine blades containing carbon fiber composite materials. This is because carbon fiber composite materials are a typical orthogonal anisotropic material, and there will be significant differences in the conductivity in different directions. Since the current in the carbon fiber is mainly conducted through the fiber bundle, and the conductivity in the direction perpendicular to the fiber bundle is relatively poor, it will cause the current distribution to show obvious directionality. The traditional simulation method does not fully consider this difference in different directions, resulting in the inability to accurately simulate the current distribution in the carbon fiber plate, and the voltage difference between the layers of the carbon fiber plate cannot be obtained. Therefore, the potential distribution of the carbon fiber plate of the wind turbine blade under the impact of lightning current cannot be accurately calculated, and there is a blind spot in the lightning protection design. Summary of the invention

[0004] The technical problem to be solved by the present disclosure is to overcome the defects in the prior art that the lightning simulation calculation of wind turbine blades is too time-consuming and cannot accurately calculate the potential distribution of each layer of the wind turbine blade under the impact of lightning current, and there are blind spots in the lightning protection design. A lightning simulation calculation method and electronic equipment for wind turbine blades are provided.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present disclosure provides a lightning simulation method for a wind turbine blade, the lightning simulation method comprising:

[0007] determining a plurality of target frequencies in a preset frequency interval;

[0008] Calculating a first current corresponding to the target frequency on a lightning current spectrum and a first impedance corresponding to the target frequency on a simulated voltage spectrum, wherein the lightning current spectrum is obtained according to a lightning current function, and the simulated voltage spectrum is obtained by inputting a steady-state voltage into a structural model of the wind turbine blade;

[0009] Acquire a lightning voltage spectrum based on a first current corresponding to the target frequency and a first impedance corresponding to the target frequency;

[0010] Performing time domain conversion on the lightning voltage spectrum to obtain lightning voltage data;

[0011] The lightning voltage data is input into the structural model of the wind turbine blade to obtain a lightning simulation result of the wind turbine blade.

[0012] Optionally, the step of acquiring a lightning voltage spectrum based on a first current corresponding to the target frequency and a first impedance corresponding to the target frequency includes:

[0013] generating a first voltage corresponding to the target frequency according to a first current corresponding to the target frequency and a first impedance corresponding to the target frequency;

[0014] The lightning voltage spectrum is acquired based on the first voltage.

[0015] Optionally, the lightning current spectrum is obtained by performing Fourier transform on the lightning current function, and the time domain conversion includes inverse Fourier transform.

[0016] Optionally, the step of determining a plurality of target frequencies in a preset frequency interval includes: the preset frequency interval is determined according to a current amplitude in the lightning current spectrum that drops to a preset threshold value.

[0017] Optionally, acquiring the lightning voltage spectrum based on the first voltage includes: interpolating waveforms formed by the first voltages corresponding to the multiple target frequencies to acquire the lightning voltage spectrum.

[0018] Optionally, the step of determining a plurality of target frequencies in a preset frequency interval includes: determining the plurality of target frequencies according to a stage at which current amplitude in the lightning current spectrum increases.

[0019] Optionally, the step of determining a plurality of target frequencies in a preset frequency interval includes:

[0020] Dividing the preset frequency interval into multiple frequency bands;

[0021] The multiple target frequencies are determined respectively according to the frequency intervals corresponding to the frequency bands, wherein a higher frequency band corresponds to a larger frequency interval.

[0022] Optionally, one frequency band includes at least 20 target frequencies.

[0023] The present disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and used to run on the processor, and the processor implements the above-mentioned lightning simulation method for wind turbine blades when executing the computer program.

[0024] The present disclosure also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the lightning simulation method for wind turbine blades is implemented.

[0025] The present disclosure also provides a computer program product, including a computer program, which implements the above-mentioned lightning simulation method for wind turbine blades when executed by a processor.

[0026] On the basis of being in accordance with the common sense in the art, the above-mentioned optional conditions can be arbitrarily combined to obtain the preferred embodiments of the present disclosure.

[0027] The positive and progressive effects of the present disclosure are: by determining multiple target frequencies in a preset frequency interval, calculating a lightning current spectrum according to a lightning current function, inputting a steady-state voltage into a structural model of a wind turbine blade to obtain a simulated voltage spectrum, generating a first current corresponding to the target frequency according to the lightning current spectrum, generating a first impedance corresponding to the target frequency according to the simulated voltage spectrum, obtaining a lightning voltage spectrum based on the first current and the first impedance, performing a time domain conversion on the obtained lightning voltage spectrum, obtaining lightning voltage data, and then inputting the lightning voltage data into the structural model of the wind turbine blade, thereby obtaining a lightning simulation result on the wind turbine blade, and reducing the complexity of the calculation through specific frequency selection and calculation methods. At the same time, converting lightning current data into lightning voltage data and inputting it into the structural model of the wind turbine blade can more accurately simulate the potential distribution of each layer of the blade under lightning impact, and provide a more accurate lightning protection design basis for the wind turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flowchart of a lightning simulation method for a wind turbine blade provided in Embodiment 1 of the present disclosure;

[0029] Figure 2 A schematic diagram of a lightning current spectrum provided in Example 1 of the present disclosure;

[0030] Figure 3 A schematic diagram of the structure of an electronic device provided in Embodiment 2 of the present disclosure. DETAILED DESCRIPTION

[0031] The present disclosure is further described below by way of examples, but the present disclosure is not limited to the scope of the examples.

[0032] Prefixes such as "first" and "second" are used in the embodiments of the present disclosure only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects.

[0033] Example 1

[0034] Figure 1 A flow chart of a lightning simulation method for wind turbine blades provided in the present disclosure.

[0035] Reference Figure 1 , the lightning simulation method for the wind turbine blade includes:

[0036] S1. Determine a plurality of target frequencies in a preset frequency range.

[0037] S2. Calculate a first current corresponding to the target frequency on a lightning current spectrum and a first impedance corresponding to the target frequency on a simulated voltage spectrum, wherein the lightning current spectrum is obtained according to a lightning current function, and the simulated voltage spectrum is obtained by inputting a steady-state voltage into a structural model of the wind turbine blade.

[0038] S3. Acquire a lightning voltage spectrum based on a first current corresponding to the target frequency and a first impedance corresponding to the target frequency.

[0039] S4. Performing time domain conversion on the lightning voltage spectrum to obtain lightning voltage data.

[0040] S5. Inputting the lightning voltage data into the structural model of the wind turbine blade to obtain a lightning simulation result of the wind turbine blade.

[0041] In an optional implementation of step S1, the preset frequency interval is determined according to the current amplitude in the lightning current spectrum that drops to a preset threshold. The lightning current spectrum shows the characteristics of lightning current changing with frequency. In the lightning current spectrum, after the frequency drops to a certain value, the amplitude of the lightning current will decrease significantly. This part of the frequency can be considered as the attenuation tail. For those frequencies that have dropped to the lightning current attenuation tail and have little impact on the system, they can be not used as target frequencies to simplify the simulation process. Specifically, the threshold can be set to the peak value of the lightning current amplitude. , then the preset frequency interval refers to an interval range consisting of all frequencies higher than the threshold.

[0042] In an optional implementation of step S1, the step of determining multiple target frequencies in a preset frequency interval includes: determining multiple target frequencies according to the stage of current amplitude rising in the lightning current spectrum. Since the high-frequency components of the lightning current function contain more amplitude peaks and frequency changes, these characteristics are more important for lightning simulation tests. In order to accurately capture these high-frequency components, it is necessary to select appropriate target frequencies. In the lightning current spectrum, the stage of rising current amplitude represents that energy is increasing rapidly, which is usually associated with the activity of high-frequency components. Therefore, by selecting a suitable frequency as the target frequency in the stage of rising current amplitude, the high-frequency part of the lightning current signal can be more effectively analyzed.

[0043] In an optional implementation scheme of step S1, the step of separately determining multiple target frequencies in a preset frequency interval includes: dividing the preset frequency interval into multiple frequency bands, and separately determining multiple target frequencies according to the frequency intervals corresponding to the frequency bands, wherein the higher the frequency band, the larger the corresponding frequency interval. In order to ensure that there are suitable target frequencies for calculation and analysis in different frequency ranges, especially under the condition that the high frequency band and the low frequency band have different characteristics, different frequency intervals are required to determine the target frequency. In the high frequency band, since the frequency changes more quickly, a larger frequency interval needs to be set to effectively capture these rapidly changing frequency characteristics. In the low frequency band, the frequency changes relatively slowly, and a smaller frequency interval needs to be set to obtain more detailed data. By reasonably dividing the frequency interval to determine and select multiple target frequencies, lightning current data can be more effectively analyzed and utilized. Figure 2 As shown, multiple target frequencies are determined in different frequency bands according to different frequency intervals. Specifically, 50 Hz is used as the frequency interval in the 50~1 kHz frequency band, 850 Hz is used as the frequency interval in the 1k~5 kHz frequency band, 5 kHz is used as the frequency interval in the 5k~25 kHz frequency band, 5 kHz is used as the frequency interval in the 25k~100 kHz frequency band, 10 kHz is used as the frequency interval in the 100k~400 kHz frequency band, and 25 kHz is used as the frequency interval in the 400k~800 kHz frequency band.

[0044] In an optional implementation, a frequency band includes at least 20 target frequencies. According to the specific characteristics of the lightning current spectrum, at least 20 target frequencies are set in each divided frequency band, and these target frequencies are used to cover the key characteristics of the high-frequency components, while also avoiding excessive amplitudes of aliased components, thereby maintaining the accuracy of data analysis.

[0045] In an optional implementation of step S2, the lightning current function can be expressed as:

[0046]

[0047] in, represents the lightning current at time 𝑡, Indicates the maximum amplitude of the current, is a proportionality constant used to adjust the current waveform to match specific experimental data or standards, is the rise time constant, which affects the speed at which the current rises to its peak value. is the decay time constant, which affects the speed at which the current drops from the peak value to zero. t represents a time variable, which represents the time from the start of the current to the current moment. The lightning current function is usually used to simulate the impact effect of lightning on the wind turbine blade. In a specific example, a voltage of 400V can be input into the structural model of the wind turbine blade to obtain the simulated voltage spectrum of the wind turbine blade. The material of the wind turbine blade can be carbon fiber, or other materials, such as carbon fiber composite materials. The simulated voltage spectrum can reflect the voltage response characteristics of the wind turbine blade at a specific frequency. The first current corresponding to the target frequency is calculated based on the generated lightning current spectrum. This step is based on the spectrum analysis results, extracting the current amplitude at a specific frequency, and calculating the first impedance corresponding to the target frequency based on the simulated voltage spectrum. In the example where the wind turbine blade is a carbon fiber blade, the calculated first impedance is actually the impedance of the metal carbon plate connection structure. In an optional implementation scheme of step S3, a first voltage corresponding to the target frequency is generated based on the first current corresponding to the target frequency and the first impedance corresponding to the target frequency; and a lightning voltage spectrum is obtained based on the first voltage.

[0048] Specifically, after calculating the first current and the first impedance at the target frequency, the first voltage corresponding to the target frequency can be calculated according to Ohm's law. In Ohm's law, voltage V is equal to current I multiplied by impedance Z ( ), and then obtain the corresponding lightning voltage spectrum based on the calculated first voltage. In an optional embodiment, obtaining the lightning voltage spectrum based on the first voltage includes: interpolating the waveform formed by the first voltages corresponding to the multiple target frequencies to obtain the lightning voltage spectrum. Specifically, in order to ensure the consistency and accuracy of voltage data at different frequencies, a linear interpolation method can be used to interpolate the waveform formed by the first voltages corresponding to the multiple target frequencies to fill the gaps between the first voltages calculated based on the target frequencies, ensuring that all frequencies within the frequency interval have corresponding voltage data. By using the linear interpolation method, continuous voltage data can be generated within the frequency interval, thereby providing a more complete spectrum view.

[0049] In a specific example, 32768 target frequencies are selected according to the first positive return stroke parameter of the lightning current function, and the time intervals between these target frequencies are , the frequency interval is 800KHz. For a structure with a high aspect ratio such as a wind turbine blade, it is very time-consuming to calculate all 32768 spectral components of the first positive return stroke of the lightning current. Therefore, some target frequencies are selected for voltage calculation, and the voltage data of the remaining frequencies are determined by interpolation method.

[0050] In an optional embodiment, the lightning current spectrum is obtained by performing Fourier transform on the lightning current function, and the time domain conversion includes inverse Fourier transform.

[0051] In a specific example, for the lightning current function,

[0052] The lightning current spectrum is obtained by setting the specific parameters of the lightning current function and performing Fourier transform on it. This step can convert the lightning current signal in the time domain into a frequency domain signal, which is helpful for analyzing the frequency components of lightning. The obtained lightning voltage spectrum needs to be converted into the time domain, that is, the inverse Fourier transform, so as to convert the lightning voltage spectrum into lightning voltage data in the time domain, so as to better observe the actual voltage waveform.

[0053] In an optional embodiment, lightning voltage data is input into the structural model of the wind blade. The material of the wind blade may be carbon fiber. The structural model can calculate the potential distribution of the wind blade under the lightning impulse, including the voltage conditions of various parts of the blade when struck by lightning. Based on the results of the potential distribution on the wind blade, high-risk areas on the wind blade can be identified to provide lightning protection design.

[0054] In this embodiment, by determining multiple target frequencies in a preset frequency range, a first current corresponding to the target frequency on the lightning current spectrum and a first impedance corresponding to the target frequency on the simulation voltage spectrum are calculated, wherein the lightning current spectrum is obtained according to the lightning current function, and the simulation voltage spectrum is obtained by inputting the steady-state voltage into the structural model of the wind turbine blade, and the lightning voltage spectrum obtained based on the first current and the first impedance is converted into lightning voltage data in the time domain, and then the lightning voltage data is input into the structural model of the wind turbine blade, so as to obtain the lightning simulation results of the wind turbine blade. In the above-mentioned lightning simulation process, the calculation process can be effectively simplified, the calculation complexity and time consumption can be reduced, and at the same time, converting the lightning current data into lightning voltage data and inputting it into the structural model of the wind turbine blade can more accurately simulate the potential distribution of each layer of the blade under lightning impact, thereby providing a more accurate lightning protection design basis for the wind turbine blade.

[0055] Example 2

[0056] Figure 3A structural schematic diagram of an electronic device provided for Embodiment 2 of the present disclosure, the electronic device comprising a memory, a processor, and a computer program stored in the memory and for running on the processor, wherein the processor implements the lightning simulation method for wind turbine blades described in any of the above embodiments when executing the computer program. Figure 3 The electronic device 90 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0057] like Figure 3 As shown, the electronic device 90 may be in the form of a general-purpose computing device, for example, it may be a server device. The components of the electronic device 90 may include, but are not limited to: at least one processor 91, at least one memory 92, and a bus 93 connecting different system components (including the memory 92 and the processor 91).

[0058] The bus 93 includes a data bus, an address bus, and a control bus.

[0059] The memory 92 may include a volatile memory, such as a random access memory (RAM) 921 and / or a cache memory 922 , and may further include a read only memory (ROM) 923 .

[0060] The memory 92 may also include a program tool 925 (or utility) having a set (at least one) of program modules 924, such program modules 924 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0061] The processor 91 executes various functional applications and data processing by running the computer program stored in the memory 92, such as the lightning simulation method for wind turbine blades provided in Example 1 of the present disclosure.

[0062] The electronic device 90 may also communicate with one or more external devices 94 (e.g., keyboards, pointing devices, etc.). Such communication may be performed via an input / output (I / O) interface 95. Furthermore, the electronic device 90 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 96. Figure 3 As shown, the network adapter 96 communicates with other modules of the electronic device 90 via the bus 93. It should be understood that although Figure 3 Not shown, other hardware and / or software modules may be used in conjunction with the electronic device 90, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems.

[0063] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided into multiple units / modules to be embodied.

[0064] Example 3

[0065] The embodiments of the present disclosure also provide a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the lightning simulation method for wind turbine blades of the above-mentioned embodiment 1 is implemented.

[0066] The readable storage medium may include but is not limited to: a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical storage device, a magnetic storage device or any suitable combination of the above.

[0067] Example 4

[0068] The embodiments of the present disclosure also provide a computer program product, including a computer program, which, when executed by a processor, implements the lightning simulation method for wind turbine blades of the above-mentioned embodiment 1.

[0069] Among them, the program code for executing the computer program product of the present disclosure can be written in any combination of one or more programming languages, and the program code can be executed completely on the user device, partially on the user device, as an independent software package, partially on the user device and partially on a remote device, or completely on the remote device.

[0070] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A lightning simulation method for a wind turbine blade, characterized in that: The lightning simulation method comprises: determining a plurality of target frequencies in a preset frequency interval; Calculating a first current corresponding to the target frequency on a lightning current spectrum and a first impedance corresponding to the target frequency on a simulated voltage spectrum, wherein the lightning current spectrum is obtained according to a lightning current function, and the simulated voltage spectrum is obtained by inputting a steady-state voltage into a structural model of the wind turbine blade; Acquire a lightning voltage spectrum based on a first current corresponding to the target frequency and a first impedance corresponding to the target frequency; Performing time domain conversion on the lightning voltage spectrum to obtain lightning voltage data; The lightning voltage data is input into the structural model of the wind turbine blade to obtain a lightning simulation result of the wind turbine blade.

2. The lightning simulation method for a wind turbine blade according to claim 1, characterized in that: The step of acquiring a lightning voltage spectrum based on a first current corresponding to the target frequency and a first impedance corresponding to the target frequency comprises: generating a first voltage corresponding to the target frequency according to a first current corresponding to the target frequency and a first impedance corresponding to the target frequency; The lightning voltage spectrum is acquired based on the first voltage.

3. The lightning simulation method for wind turbine blades according to claim 1, characterized in that: The lightning current spectrum is obtained by performing Fourier transform on the lightning current function, and the time domain conversion includes inverse Fourier transform.

4. The lightning simulation method for a wind turbine blade according to claim 1, characterized in that: The step of determining a plurality of target frequencies in a preset frequency interval comprises: The preset frequency interval is determined according to the current amplitude in the lightning current spectrum that drops to a preset threshold.

5. The lightning simulation method for wind turbine blades according to claim 2, characterized in that: The acquiring the lightning voltage spectrum based on the first voltage comprises: The waveforms formed by the first voltages corresponding to the multiple target frequencies are interpolated to obtain the lightning voltage spectrum.

6. The lightning simulation method for a wind turbine blade according to claim 1, characterized in that: The step of determining a plurality of target frequencies in a preset frequency interval comprises: The multiple target frequencies are determined according to the stages of current amplitude rise in the lightning current spectrum.

7. The lightning simulation method for a wind turbine blade according to any one of claims 1 to 5, characterized in that: The step of determining a plurality of target frequencies in a preset frequency interval comprises: Dividing the preset frequency interval into multiple frequency bands; The multiple target frequencies are determined respectively according to frequency intervals corresponding to the multiple frequency bands, wherein a higher frequency band corresponds to a larger frequency interval.

8. The lightning simulation method for a wind turbine blade according to claim 7, characterized in that: One frequency band includes at least 20 target frequencies.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and used to run on the processor, characterized in that: When the processor executes the computer program, the lightning simulation method for a wind turbine blade according to any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the lightning simulation method for a wind turbine blade according to any one of claims 1 to 8 is implemented.

11. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the lightning simulation method for a wind turbine blade according to any one of claims 1 to 8 is implemented.

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