Overhead ground wire detection parameter optimization method, system and equipment based on ultrasonic guided waves and medium

Abstract

The invention discloses an overhead ground wire detection parameter optimization method, system and device based on ultrasonic guided waves and a medium, and the method comprises the steps: analyzing the propagation characteristics of the ultrasonic guided waves of an overhead ground wire based on the related parameters of the overhead ground wire, and calculating the number of initial transducers for obtaining the ultrasonic guided waves; according to the ultrasonic guided wave propagation characteristics of the overhead ground wire, the initial excitation frequency of ultrasonic guided waves is obtained; signal modulation is carried out based on the frequency and time constraint of the ultrasonic guided wave excitation signal, and the initial modulation period number of the ultrasonic guided wave is obtained; and establishing a finite element model of the overhead ground wire, inputting the preliminary transducer number, the preliminary excitation frequency and the preliminary modulation period number into the finite element model, and outputting an optimal parameter combination through multiple times of simulation. By optimizing parameters such as the number of transducers, the excitation frequency and the modulation period for ultrasonic guided wave detection, a low-order axisymmetric longitudinal guided wave mode can be stably excited, high-order mode and noise interference are inhibited, and the detection sensitivity and the positioning precision can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of overhead ground wire detection, and in particular to an overhead ground wire detection parameter optimization method, system, equipment and medium based on ultrasonic guided waves. Background Art

[0002] Overhead ground wires, as crucial lightning protection and grounding components in power systems, are widely used in transmission lines to guide lightning currents into the ground and enhance system safety. However, over their long service lives, overhead ground wires are often subject to a variety of destructive factors, including material aging, environmental corrosion, wind-induced fatigue, and mechanical impact. These wires are prone to structural defects such as strand breakage, wear, and corrosion-induced cracks. In severe cases, these defects can cause system grounding failure, resulting in equipment damage and even personal injury.

[0003] Currently, methods for inspecting overhead ground wires primarily include manual inspections, optical telescope observations, drone inspections, infrared imaging, and local electrical performance testing. However, these methods have significant limitations: First, insufficient detection accuracy makes it difficult to detect small defects early on; second, low inspection frequency and limited coverage make it difficult to implement real-time health monitoring of large-scale lines. This is particularly challenging and carries high safety risks in areas with high altitudes and complex terrain. Ultrasonic guided wave inspection technology has been widely used in rail inspection due to its long-range detection capabilities. It can provide full coverage inspections of tens or even hundreds of meters from a single inspection point. Compared to traditional inspection methods, ultrasonic guided waves do not require full contact coverage, making them suitable for remote and online monitoring scenarios and highly valuable for engineering deployment. However, overhead ground wires are typically constructed from multiple strands of steel-core aluminum stranded wire. Guided wave propagation suffers from multimodality, strong scattering, and energy attenuation, significantly impacting the stability of the detection signal and the ability to identify defects. Therefore, optimizing the inspection parameters is essential for efficient and accurate inspection of overhead ground wires. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides an overhead ground wire detection parameter optimization method based on ultrasonic guided waves to solve the problems of existing overhead ground wire detection methods, such as insufficient detection accuracy, limited coverage, difficulty in real-time monitoring of early minor defects, and difficulty in detection in complex terrain.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves, comprising:

[0008] Get the parameters related to overhead ground wire;

[0009] Based on the relevant parameters of the overhead ground wire, analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire, and calculating the preliminary number of transducers for obtaining the ultrasonic guided wave;

[0010] According to the ultrasonic guided wave propagation characteristics of the overhead ground wire, the preliminary excitation frequency of the ultrasonic guided wave is obtained;

[0011] Perform signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain the preliminary modulation cycle number of the ultrasonic guided wave;

[0012] A finite element model of the overhead ground wire is established, the preliminary number of transducers, the preliminary excitation frequency and the preliminary number of modulation cycles are input into the finite element model, and an optimal parameter combination is output through multiple simulations.

[0013] As a preferred solution of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves described in the present invention, the calculation of the preliminary number of transducers for obtaining ultrasonic guided waves includes:

[0014] Analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire, and obtaining the guided wave mode of the ultrasonic guided wave in the overhead ground wire;

[0015] Based on the waveguide mode and the constraint of suppressing high-order bending modes, the preliminary number of transducers for ultrasonic guided waves is calculated.

[0016] The beneficial effects of this preferred technical solution are: by analyzing the waveguide propagation characteristics of the cylindrical structure and combining it with the high-order bending mode suppression constraints, the precise calculation of the number of transducers is achieved, which can effectively reduce multimodal interference, concentrate the waveguide energy on the target low-order axisymmetric mode, and improve the recognition of the defect reflection signal.

[0017] As a preferred solution of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves described in the present invention, obtaining the preliminary excitation frequency of the ultrasonic guided waves includes:

[0018] According to the propagation attenuation characteristics of ultrasonic guided waves in overhead ground wire materials, frequency scanning is performed within the threshold range;

[0019] By testing the purity of the guided wave mode at different frequencies point by point, the frequency range that can stably excite low-order axisymmetric longitudinal modes and suppress high-order modes is screened out to obtain the preliminary excitation frequency of the ultrasonic guided wave.

[0020] This preferred technical solution has the following advantages: frequency scanning within the threshold range and selecting the frequency range that stably excites low-order modes can avoid the strong attenuation effect of overhead ground wire materials on specific frequencies. By accurately selecting frequency points, the number of detection points can be significantly reduced.

[0021] As a preferred scheme of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves provided by the application, wherein: the preliminary modulation period number of the ultrasonic guided waves is obtained, including:

[0022] The Hanning window is used to modulate the excitation signal, the modulation period number range of different periods is set, and the spectral leakage degree and time resolution of the signal under different period numbers are analyzed;

[0023] According to the preset spectral lobe suppression standard and defect positioning error standard, the preliminary modulation period number is obtained.

[0024] The beneficial effects of the preferred technical scheme are: the Hanning window modulation is used in combination with spectral leakage and time resolution analysis to realize the optimal balance of the time domain and frequency domain characteristics of the excitation signal. By setting the modulation range of different periods, the spectral lobe peak value can be suppressed, and frequency aliasing interference can be effectively avoided.

[0025] As a preferred scheme of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves provided by the application, wherein: the preliminary transducer number, the preliminary excitation frequency and the preliminary modulation period number are input into the finite element model, and the optimal parameter combination is output through multiple simulations, including:

[0026] The finite element model of the overhead ground wire is established, the transducer excitation condition is simulated and the grid is divided, and the grid density is ensured to meet the analytical requirements of the guided wave wavelength;

[0027] The preliminary transducer number, the preliminary excitation frequency and the preliminary modulation period number are input into the finite element model, the modal distribution, energy attenuation and defect reflection signal of the ultrasonic guided wave in different propagation distances are simulated multiple times, and the simulation results are obtained;

[0028] Based on the simulation results, the transducer number, the excitation frequency and the modulation period number are adjusted to obtain the optimal parameter combination.

[0029] The beneficial effects of the preferred technical scheme are: the limitations of traditional empirical parameter design are broken through, an accurate parameter configuration method is provided for the detection of complex structures, and the global optimization of the detection system is realized through iterative adjustment of the parameters of the finite element model.

[0030] As a preferred scheme of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves provided by the application, wherein: the preliminary transducer number of the ultrasonic guided waves is calculated as:

[0031]

[0032] Wherein, N is the number of transducers, R is the radius of the ground wire, f is the excitation frequency, n max is the highest order bending mode order to be suppressed, c f is the propagation speed of the bending wave.

[0033] As a preferred solution of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves described in the present invention, the simulation grid division is represented as follows:

[0034]

[0035] Where c is the speed, f0 is the center frequency, h o is the grid size.

[0036] In a second aspect, the present invention provides an overhead ground wire detection parameter optimization system based on ultrasonic guided waves, comprising: a data acquisition module for acquiring overhead ground wire related parameters;

[0037] a data calculation module for analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire, and calculating the preliminary number of transducers for obtaining the ultrasonic guided wave; obtaining the preliminary excitation frequency of the ultrasonic guided wave based on the ultrasonic guided wave propagation characteristics of the overhead ground wire; and performing signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain the preliminary number of modulation cycles of the ultrasonic guided wave;

[0038] The simulation optimization module is used to establish a finite element model of the overhead ground wire, input the preliminary number of transducers, preliminary excitation frequency and preliminary number of modulation cycles into the finite element model, and output the optimal parameter combination through multiple simulations.

[0039] In a third aspect, the present invention provides an electronic device, comprising:

[0040] memory and processor;

[0041] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves are implemented.

[0042] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves.

[0043] Compared with the existing technology, the beneficial effects of the present invention are as follows: by optimizing parameters such as the number of transducers, excitation frequency and modulation period of ultrasonic guided wave detection, the present invention can stably excite low-order axisymmetric longitudinal guided wave modes, suppress high-order modes and noise interference, and improve detection sensitivity and positioning accuracy; at the same time, the detection efficiency is improved by dozens of times compared with traditional methods, and it is suitable for online monitoring in harsh environments such as high altitudes and complex terrains, providing an efficient and reliable technical solution for structural health monitoring of overhead ground wires, effectively reducing the risk of manual inspections, and ensuring the safe operation of power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 The figure is a schematic diagram of the overall process of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves according to one embodiment of the present invention. DETAILED DESCRIPTION

[0046] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0047] Example 1, with reference to Figure 1 , as one embodiment of the present invention, provides a method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves, comprising:

[0048] S100: Obtaining parameters related to the overhead ground wire;

[0049] S102: Analyze the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire, and calculate the preliminary number of transducers for obtaining the ultrasonic guided wave;

[0050] S104: Obtaining a preliminary excitation frequency of the ultrasonic guided wave according to the ultrasonic guided wave propagation characteristics of the overhead ground wire;

[0051] S106: performing signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain a preliminary modulation cycle number of the ultrasonic guided wave;

[0052] S108: Establish a finite element model of the overhead ground wire, input a preliminary number of transducers, a preliminary excitation frequency, and a preliminary number of modulation cycles into the finite element model, and output an optimal parameter combination through multiple simulations.

[0053] It should be noted that the present invention obtains relevant parameters of the overhead ground wire, analyzes the waveguide propagation characteristics of its cylindrical structure to calculate the preliminary number of transducers, and can suppress high-order bending modes in a targeted manner, focus on exciting low-order axisymmetric longitudinal waveguides, and improve signal purity; obtains the preliminary excitation frequency based on the waveguide propagation attenuation characteristics, and can balance the signal energy and attenuation speed within the effective detection distance, thereby expanding the coverage range of a single detection; combines the frequency and time constraints to modulate the number of signal cycles, and can suppress spectrum leakage through the Hanning window, thereby enhancing the signal energy concentration while ensuring the defect positioning accuracy; finally, through the iterative simulation optimization of the finite element model, the parameter combination is achieved to achieve the global optimization of the waveguide mode, propagation distance and detection accuracy.

[0054] Example 2, reference Figure 1 , which is an embodiment of the present invention, provides an overhead ground wire detection parameter optimization method based on ultrasonic guided waves based on the above embodiments.

[0055] In this embodiment, the overhead ground wire parameters in step S100 include the ground wire radius, material density, elastic modulus, Poisson's ratio, preset maximum operating frequency, and the order of the highest-order bending mode to be suppressed. The ground wire radius is used to calculate the number of transducers and the wavelength of the guided wave; the material density, elastic modulus, and Poisson's ratio are used to derive the guided wave propagation velocity; the preset maximum operating frequency, combined with the ground wire structure, determines the range of guided wave mode excitation; and the order of the highest-order bending mode to be suppressed is used to define the calculation boundary for the number of transducers.

[0056] In an optional embodiment, the overhead ground wire parameters in step S100 may also include the number of conductor strands, strand diameter, surface corrosion level, and historical defect distribution data. The number of conductor strands and strand diameter are used to refine the modeling of the scattering characteristics of guided waves in multi-stranded wires; the surface corrosion level affects the correction of the guided wave attenuation coefficient; and historical defect distribution data can assist in setting defect types and locations in the simulation, improving the targeted nature of parameter optimization.

[0057] In an embodiment of the present invention, step S102 analyzes the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire and calculates the preliminary number of transducers for obtaining the ultrasonic guided wave, and further includes sub-steps A1-A2:

[0058] A1: Based on the relevant parameters of the overhead ground wire, analyze the ultrasonic guided wave propagation characteristics of the overhead ground wire and obtain the guided wave mode of the ultrasonic guided wave in the overhead ground wire;

[0059] A2: Based on the guided wave mode, combined with the constraint of suppressing high-order bending mode, the preliminary transducer number of ultrasonic guided wave is calculated.

[0060] Specifically, in an isotropic elastic unbounded medium, the Navier motion equation lays the foundation for understanding the propagation of elastic waves, and the expression is:

[0061]

[0062] Where λ and μ are Lame constants, u is the displacement vector, ▽ is the Laplace operator, and ρ is the material density.

[0063] Using Helmholtz decomposition, u can be written as the sum of a compressive scalar potential θ and an incompressible vector potential Φ, which is expressed as:

[0064] u = ▽θ + ▽×Φ

[0065] ▽×Φ = 0

[0066] Two formulas are calculated to describe the unknown potential, which control the longitudinal wave and transverse wave respectively, and are expressed as:

[0067]

[0068] Where c l and c s are the velocities of longitudinal and transverse waves, expressed as:

[0069]

[0070] Therefore, in an infinite medium, longitudinal and transverse waves can be propagated, while in a restricted structure such as an overhead ground wire, guided waves are geometrically constrained and can only propagate along the structure axis, forming various guided wave modes. The type and number of guided wave modes are affected by factors such as structure shape, material properties and excitation frequency.

[0071] In a cylindrical structure, the vibration mode is based on the following format: X(n,m), where X represents the vibration mode, such as longitudinal axisymmetric L, torsional axisymmetric T and non-axisymmetric also represented as bending F; n is a positive integer, representing the harmonic number in the circumferential direction; m represents the order of the mode.

[0072] In the ultrasonic guided wave operating frequency range, there are three axisymmetric modes that can be excited, denoted as: L(0,1), T(0,1) and L(0,2); among them, the L(0,1) wave mode has radial and axial displacement, the T(0,1) wave mode has circumferential displacement, and the L(0,2) wave mode mainly has axial displacement.

[0073] In this embodiment, it is generally desirable to excite low-order, low-attenuation, and simple axisymmetric guided wave modes. To achieve this, the excitation frequency and the number of transducers must be appropriately designed. Using different numbers of transducers can selectively excite specific modes.

[0074] For example, in an 8-transducer configuration, high-order bending modes are easily induced when the excitation frequency exceeds 14 kHz, while in a 14-transducer configuration, high-order modes are only excited at frequencies above 18 kHz. This indicates that increasing the number of transducers helps suppress high-order modes while improving signal strength and signal-to-noise ratio.

[0075] To meet the application requirements of overhead ground wire detection, a minimum number of transducers must be designed to excite the longitudinal axisymmetric modes L(0,1) and L(0,2), while suppressing the excitation of the bending mode F(n,m) and reducing signal noise.

[0076] In this embodiment, the preliminary number of transducers for ultrasonic guided waves is calculated as:

[0077]

[0078] Where N is the number of transducers, R is the ground radius, f is the excitation frequency, and n max is the highest order bending mode to be suppressed, c f is the propagation speed of the bending wave.

[0079] In an optional embodiment, a preliminary transducer number can be obtained through a finite element simulation pre-screening method, that is, first setting a transducer number range, using a finite element model to simulate the energy distribution of the waveguide mode under different numbers, screening out a transducer number range in which the high-order bending mode energy accounts for less than 15% and the longitudinal mode energy accounts for more than 70%, and then combining the formula calculation results to determine the preliminary value.

[0080] In another optional embodiment, the preliminary number of transducers can also be obtained through an experimental calibration method. That is, after calculating the theoretical value according to the formula, an excitation experiment with different numbers of transducers is carried out on an actual overhead ground wire sample. The guided wave signal is collected through the sensor array, the amplitude of the high-order mode in the signal spectrum is analyzed, and the number of transducers is dynamically adjusted until the modal suppression requirements are met.

[0081] It should be noted that this invention analyzes the guided wave propagation characteristics of the cylindrical structure of an overhead ground wire. Based on the Navier equations of motion and Helmholtz decomposition theory, it clarifies the generation mechanisms of longitudinal waves, transverse waves, and guided wave modes. It then specifically associates the number of transducers with the ground wire radius, excitation frequency, and the need to suppress high-order bending modes. The preliminary number of transducers is quantitatively calculated using a formula. This method can effectively suppress the interference of high-order bending modes in overhead ground wire detection, stably excite low-attenuation longitudinal axisymmetric modes, and simultaneously improve signal strength and signal-to-noise ratio by increasing the number of transducers, achieving the goal of obtaining a pure guided wave mode with a minimum number of transducers. This method provides theoretical support and parameter design basis for long-distance, high-sensitivity overhead ground wire defect detection, improving detection efficiency and reliability.

[0082] In an embodiment of the present invention, step S104 obtains a preliminary excitation frequency of the ultrasonic guided wave according to the propagation attenuation characteristics of the ultrasonic guided wave in the overhead ground wire, and further includes sub-steps B1-B2:

[0083] B1: Based on the propagation attenuation characteristics of ultrasonic guided waves in overhead ground wire materials, frequency scanning is performed within the threshold range;

[0084] B2: By testing the purity of the guided wave mode at different frequencies point by point, the frequency range that can stably excite low-order axisymmetric longitudinal modes and suppress high-order modes is screened out to obtain the preliminary excitation frequency of the ultrasonic guided wave.

[0085] In this embodiment of the present invention, the excitation signal frequency range is set to 10kHz to 30kHz, with a step size of 1kHz. This frequency range covers the typical frequency range of ultrasonic guided wave modes, allowing for the excitation of longitudinal wave modes while avoiding excessively high frequencies that would cause rapid wave attenuation or multipath propagation. Setting the step size to 1kHz allows for a detailed frequency sweep, ensuring effective excitation of the desired mode across the entire frequency range, meeting diverse detection requirements.

[0086] It should be noted that by performing point-by-point scanning in 1kHz steps across the frequency range of 10kHz to 30kHz, the present invention systematically analyzes the purity and propagation attenuation characteristics of guided wave modes at different frequencies, accurately identifying the optimal excitation range for low-order axisymmetric longitudinal modes. This method effectively avoids the limited detection range caused by rapid attenuation in high-frequency bands, while also circumventing the insufficient defect resolution caused by long wavelengths in low-frequency bands.

[0087] In an embodiment of the present invention, step S106 performs signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain a preliminary modulation cycle number of the ultrasonic guided wave, and further includes sub-steps C1-C2:

[0088] C1: Modulate the excitation signal with a Hanning window, set different ranges of modulation cycle numbers for different periods, and analyze the spectral leakage and time resolution of the signal under different cycle numbers;

[0089] C2: Obtain the preliminary modulation cycle number according to the preset spectral sidelobe suppression standard and defect positioning error standard.

[0090] In the embodiment of the present application, a flexible transducer is selected, which can effectively fit various curved surfaces or irregular surfaces, ensuring good contact between the transducer and the ground wire to achieve stable ultrasonic wave transmission and signal acquisition. The excitation signal adopts a pulse echo configuration. The pulse echo configuration can use the transducer to send an ultrasonic pulse and simultaneously receive the echo signal reflected from the defect or structural interface, that is, the transducer acts as both an exciter and a receiver, and defect detection is achieved through one excitation and echo reception. The input excitation signal is modulated with a 5-cycle Hanning window. The Hanning window smoothes the signal intensity at the beginning and end of the signal, thereby reducing spectral leakage and sidelobe effect, reducing noise interference, and optimizing signal quality.

[0091] In an alternative embodiment, a Gaussian window modulation is used to obtain a preliminary modulation cycle number, a range of 3-7 cycles of modulation cycle numbers is set, a Gaussian window function is applied to the excitation signal of each cycle number, the signal spectral bandwidth and energy concentration are analyzed, and the optimal cycle number is selected according to the preset sidelobe threshold and time resolution requirements.

[0092] In another alternative embodiment, a Blackman window modulation is used to obtain a preliminary modulation cycle number, the modulation cycle number is dynamically adjusted to 4-6 cycles, a window function parameter model is established in combination with the scattering characteristics of the overhead ground wire, the weighting coefficient is optimized through an algorithm to compensate for scattering attenuation, and the preliminary cycle number is determined according to the spectral sidelobe suppression rate and signal-to-noise ratio.

[0093] In the embodiment of the present application, the finite element model of the overhead ground wire is established in step S108, the preliminary transducer number, the preliminary excitation frequency and the preliminary modulation cycle number are input into the finite element model, and the optimal parameter combination is output through multiple simulations, which further includes sub-steps D1-D3:

[0094] D1: Establish a finite element model of the overhead ground wire, simulate the transducer excitation conditions and divide the grid to ensure that the grid density meets the analytical requirements of the guided wave wavelength;

[0095] D2: Input the preliminary transducer number, the preliminary excitation frequency and the preliminary modulation cycle number into the finite element model, simulate the modal distribution, energy attenuation and defect reflection signal of the ultrasonic guided wave within different propagation distances multiple times, and obtain the simulation results;

[0096] D3: Adjust the transducer number, excitation frequency and modulation cycle number based on the simulation results to obtain the optimal parameter combination.

[0097] In this embodiment, to further analyze the propagation of ultrasonic guided waves in the overhead ground wire, a finite element analysis method is used to construct a finite element model of the overhead ground wire. In the finite element model, the transducer configuration is represented in the form of point loads.

[0098] The point load is applied parallel to the length of the ground wire to generate a longitudinal wave pattern. The pressure point is a sine wave modulated by the Hanning window function, and its expression is:

[0099]

[0100] In this implementation, to accurately depict the wave propagation throughout the structure through dynamic transient simulations, the mesh must be calculated to an optimal cell length. The wave equation requires that the meshing match the time step in the solver to obtain an accurate solution. The mesh size requires at least 8 second-order cells per wavelength. The mesh size is calculated using the following formula:

[0101]

[0102] Where c is the speed, f0 is the center frequency, h o is the grid size.

[0103] The signal arrival time is calculated using the group velocity of the longitudinal wave mode using the following formula:

[0104]

[0105] Where d is the distance from the transmitter to the receiver, v g is the group velocity of the longitudinal wave mode at the operating frequency.

[0106] Finite element modeling was used to optimize the number of transducers in the array to eliminate the excitation of higher-order modes. Results showed that when the number of transducers was 14 or 20, the guided wave modes were pure, the signal amplitude was high, and the noise interference was low, approximately ±0.002μm. However, when the number of transducers was 8 or fewer, the signal was chaotic, with multiple modes coexisting and high noise, approximately ±0.05μm, which was not conducive to defect identification.

[0107] In this implementation, to further enhance the effectiveness of ultrasonic guided waves in overhead ground wire detection, the number of excitation signal cycles must be rationally designed to achieve a balance between frequency bandwidth and temporal resolution. Generally, a wider frequency bandwidth means more frequency components in the excitation signal, which helps excite multiple guided wave modes, but also more easily induces dispersion and reduces modal selectivity. Conversely, a higher temporal resolution means shorter pulses, which facilitates precise location of defect reflection signals but may result in insufficient modal energy or aliasing.

[0108] The frequency range (i.e., bandwidth) of the excitation signal is usually defined as the difference between the upper and lower frequencies of the main lobe, and its calculation formula is:

[0109] BW=f high -f low

[0110] Where BW is the frequency bandwidth, f high and f low Represent the upper and lower limits of the main lobe frequency respectively.

[0111] Changes in the number of excitation signal cycles have a significant impact on the bandwidth and time domain characteristics: when the number of cycles is large, the pulse is short, the bandwidth is wide, and the time resolution is improved, but the spectrum expansion will cause mode aliasing and increase the risk of dispersion.

[0112] It should be noted that, while maintaining modal selectivity, a trade-off must be made between modal purity, signal-to-noise ratio, dispersion control, and spatial resolution. Finite element simulation analysis shows that using a 5-cycle Hanning window modulated sinusoidal excitation, combined with an 18kHz center frequency and a 14-transducer array configuration, can stably excite the L(0,2) mode. This ensures the stability of guided wave propagation while balancing time compression and frequency bandwidth, resulting in excellent detection performance.

[0113] In an optional embodiment, a multi-physics field coupled finite element model analysis can be established to obtain the optimal parameter combination, a three-dimensional model including the transducer, overhead ground wire and air is constructed, the piezoelectric material properties, the mechanical behavior of the contact interface and the acoustic wave propagation equation are coupled and solved, and a full parameter scan is performed by setting a 12-24 transducer array with a 15-25kHz frequency range and a 3-7 cycle modulation parameter. The far-field scattering characteristics are calculated using the acoustic boundary element method, and finally the optimal parameter combination is output through a multi-objective optimization algorithm.

[0114] In another optional embodiment, an equivalent continuum discrete element hybrid model analysis can be established to obtain the optimal parameter combination, the multi-strand stranded wire structure is equivalent to an anisotropic continuum, the Mindlin plate theory is used to describe the waveguide propagation, and a discrete element model is embedded in the defect area to simulate the stress concentration effect at the crack tip; parametric simulation is performed, 10-20 transducers, 16-22kHz frequency and 4-6 cycle modulation are set, the modal purity is evaluated by wavelet packet decomposition, and finally the parameter configuration with maximum defect echo energy and sidelobe ratio ≤-35dB is determined based on the Bayesian optimization algorithm.

[0115] In Example 3, the above is a schematic scheme of a method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves. It should be noted that the technical scheme of this system for optimizing overhead ground wire detection parameters based on ultrasonic guided waves and the technical scheme of the method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves are based on the same concept. For details not described in detail in the technical scheme of the system for optimizing overhead ground wire detection parameters based on ultrasonic guided waves in this embodiment, please refer to the description of the technical scheme of the method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves.

[0116] This embodiment further provides an overhead ground wire detection parameter optimization system based on ultrasonic guided waves, comprising:

[0117] Data acquisition module, used to obtain overhead ground wire related parameters;

[0118] A data calculation module is used to analyze the ultrasonic guided wave propagation characteristics of the overhead ground wire based on relevant parameters of the overhead ground wire and calculate the preliminary number of transducers for obtaining the ultrasonic guided wave; obtain the preliminary excitation frequency of the ultrasonic guided wave based on the ultrasonic guided wave propagation characteristics of the overhead ground wire; perform signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain the preliminary number of modulation cycles of the ultrasonic guided wave;

[0119] The simulation optimization module is used to establish a finite element model of the overhead ground wire, input the preliminary number of transducers, preliminary excitation frequency and preliminary number of modulation cycles into the finite element model, and output the optimal parameter combination through multiple simulations.

[0120] This embodiment also provides an electronic device suitable for optimizing overhead ground wire detection parameters based on ultrasonic guided waves, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the overhead ground wire detection parameter optimization method based on ultrasonic guided waves as proposed in the above embodiment.

[0121] This embodiment further provides a storage medium having a computer program stored thereon. When the program is executed by a processor, the method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves as proposed in the above embodiment is implemented.

[0122] The storage medium proposed in this embodiment and the method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves proposed in the above embodiment belong to the same inventive concept. Technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0123] Through the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented with the help of software and necessary general hardware, and of course can also be implemented by hardware. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a computer's floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0124] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves, characterized in that: include: Get the parameters related to overhead ground wire; Based on the relevant parameters of the overhead ground wire, analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire, and calculating the preliminary number of transducers for obtaining the ultrasonic guided wave; According to the ultrasonic guided wave propagation characteristics of the overhead ground wire, the preliminary excitation frequency of the ultrasonic guided wave is obtained; Perform signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain the preliminary modulation cycle number of the ultrasonic guided wave; A finite element model of the overhead ground wire is established, the preliminary number of transducers, the preliminary excitation frequency and the preliminary number of modulation cycles are input into the finite element model, and an optimal parameter combination is output through multiple simulations.

2. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 1, wherein: Calculate the preliminary number of transducers required to acquire ultrasonic guided waves, including: Analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire, and obtaining the guided wave mode of the ultrasonic guided wave in the overhead ground wire; Based on the guided wave mode and the constraint of suppressing high-order bending modes, the preliminary number of transducers for ultrasonic guided waves is calculated.

3. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 2, wherein: Obtain the preliminary excitation frequency of ultrasonic guided waves, including: According to the propagation attenuation characteristics of ultrasonic guided waves in overhead ground wire materials, frequency scanning is performed within the threshold range; By testing the purity of the guided wave mode at different frequencies point by point, the frequency range that can stably excite low-order axisymmetric longitudinal modes and suppress high-order modes is screened out to obtain the preliminary excitation frequency of the ultrasonic guided wave.

4. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 3, wherein: Obtain the preliminary modulation cycle number of the ultrasonic guided wave, including: The excitation signal is modulated using a Hanning window. By setting the range of modulation cycles of different periods, the spectrum leakage degree and time resolution of the signal under different cycle numbers are analyzed. According to the preset spectrum sidelobe suppression standard and defect location error standard, the preliminary modulation cycle number is obtained.

5. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 4, wherein: The preliminary number of transducers, preliminary excitation frequency, and preliminary number of modulation cycles are input into a finite element model, and an optimal parameter combination is output through multiple simulations, including: Establish a finite element model of the overhead ground wire, simulate the transducer excitation conditions, and divide the mesh to ensure that the mesh density meets the analytical requirements of the guided wave wavelength; Inputting the preliminary number of transducers, preliminary excitation frequency, and preliminary number of modulation cycles into a finite element model, simulating the modal distribution, energy attenuation, and defect reflection signal of ultrasonic guided waves at different propagation distances multiple times, and obtaining simulation results; Based on the simulation results, the number of transducers, excitation frequency, and modulation cycles are adjusted to obtain the optimal parameter combination.

6. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 2, wherein: The preliminary transducer number for calculating ultrasonic guided waves is expressed as: Where N is the number of transducers, R is the ground radius, f is the excitation frequency, and n max is the highest order bending mode to be suppressed, c f is the propagation speed of the bending wave.

7. The method for optimizing overhead ground wire detection parameters based on ultrasonic guided waves according to claim 5, wherein: The simulation grid is expressed as: Where c is the speed, f0 is the center frequency, h o is the grid size.

8. An overhead ground wire detection parameter optimization system based on ultrasonic guided waves, applying the method according to any one of claims 1 to 7, characterized in that: include: Data acquisition module, used to obtain overhead ground wire related parameters; a data calculation module for analyzing the ultrasonic guided wave propagation characteristics of the overhead ground wire based on the relevant parameters of the overhead ground wire, and calculating the preliminary number of transducers for obtaining the ultrasonic guided wave; obtaining the preliminary excitation frequency of the ultrasonic guided wave based on the ultrasonic guided wave propagation characteristics of the overhead ground wire; and performing signal modulation based on the frequency and time constraints of the ultrasonic guided wave excitation signal to obtain the preliminary number of modulation cycles of the ultrasonic guided wave; The simulation optimization module is used to establish a finite element model of the overhead ground wire, input the preliminary number of transducers, preliminary excitation frequency and preliminary number of modulation cycles into the finite element model, and output the optimal parameter combination through multiple simulations.

9. An electronic device, characterized in that: include: memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that It stores computer-executable instructions, which, when executed by a processor, implement the steps of the overhead ground wire detection parameter optimization method based on ultrasonic guided waves as described in any one of claims 1 to 7.

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