Conductive device detection method and apparatus, electronic device, and storage medium

Abstract

The present disclosure relates to a conductive device detection method and device, an electronic device and a storage medium. The conductive device detection method comprises: determining at least one parameter of a time-domain trapezoidal pulse sequence according to an attribute parameter of a measured conductive device and a detection requirement; generating the time-domain trapezoidal pulse sequence according to the at least one parameter of the time-domain trapezoidal pulse sequence, and inputting the time-domain trapezoidal pulse sequence to the measured conductive device; detecting input impedance of each measured frequency point in a measured frequency range of the measured conductive device, and generating an input impedance spectrum according to the input impedance of each measured frequency point in the measured frequency range of the measured conductive device.

Description

Technical Field

[0001] This disclosure relates to the field of power system technology, specifically to a method and apparatus for detecting conductive devices, electronic equipment, and storage medium. Background Technology

[0002] Power cables possess high insulation performance and mechanical strength. With the continuous development of the power industry, their laying mileage is constantly increasing, and their proportion in power transmission and distribution lines is gradually growing, making them crucial. However, during long-term operation, factors such as cable bending and damage caused by construction, high temperature and humidity in the cable's environment, and cable vibration can all lead to defects such as insulation deterioration and water-blocking layer erosion. If these defects are not detected in time, they will eventually cause insulation breakdown, threatening the safe and stable operation of the power transmission and transformation system and causing huge economic losses. Therefore, it is necessary to conduct condition monitoring of power cables to detect defects in advance and eliminate potential hazards.

[0003] Among current condition detection methods, the traveling wave method is widely used, which can be broadly divided into two categories: time-domain reflectometry (TDR) and frequency-domain reflectometry (FDR). TDR methods extract defect information based on the time-domain characteristics of pulse signals reflected in the cable, while FDR methods primarily locate defects based on the frequency-domain characteristics of the electrical parameters at the cable's head. In field applications, the time-domain signal used by TDR methods is prone to attenuation, and when multiple defects coexist, signal aliasing is severe, making it difficult to specifically identify defects. In FDR methods, the broadband impedance spectrum (BIS) method analyzes the input impedance spectrum at the cable's head to extract impedance changes caused by defects, thereby locating cable defects. Its feasibility and final results are relatively better.

[0004] The relevant technology uses an impedance analyzer to obtain the broadband impedance spectrum of the cable. However, this method is difficult to effectively detect the far end of long-distance cables and is easily affected by electromagnetic interference in the environment, resulting in insufficient detection accuracy. Summary of the Invention

[0005] To overcome the problems existing in the related technologies, this disclosure provides a virtual camera control method and apparatus, electronic device and storage medium to solve the defects in the related technologies.

[0006] According to a first aspect of the present disclosure, a method for detecting a conductive device is provided, the method comprising: Based on the property parameters of the conductive device under test and the testing requirements, determine at least one parameter of the time-domain trapezoidal pulse sequence; A time-domain trapezoidal pulse sequence is generated based on at least one parameter of the time-domain trapezoidal pulse sequence, and the time-domain trapezoidal pulse sequence is input to the conductive device under test; The input impedance of the conductive device under test at each measured frequency point within the measured frequency band is detected, and an input impedance spectrum is generated based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

[0007] In some possible embodiments of this disclosure, determining at least one parameter of the time-domain trapezoidal pulse sequence based on the property parameters of the conductive device under test and the detection requirements includes: The repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test. Based on the detection accuracy requirements, determine the sweep bandwidth of the frequency band under test, and determine the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence based on the prime sweep bandwidth.

[0008] In some possible embodiments of this disclosure, determining the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence based on the length of the conductive device under test includes: Based on the length of the conductive device under test and the propagation speed of electromagnetic waves, determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence.

[0009] In some possible embodiments of this disclosure, the repetition frequency of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep resolution of the measured frequency point in the measured frequency band.

[0010] In some possible embodiments of this disclosure, the rise time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep bandwidth of the measured frequency band.

[0011] In some possible embodiments of this disclosure, the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence are related to the frequency points in the measured frequency band where the excitation amplitude is 0.

[0012] In some possible embodiments of this disclosure, detecting the input impedance of the conductive device under test at each measured frequency point within the measured frequency band includes: The detection system is used to output the time-domain trapezoidal pulse sequence. The detection system is used to detect the open-circuit voltage and output impedance of the detection system, as well as the voltage at the beginning of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test. The open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band is determined based on the open-circuit voltage of the detection system, and the first-end voltage component of the first-end voltage at each measured frequency point within the measured frequency band is determined based on the first-end voltage of the conductive device under test. Based on the open-circuit voltage components at each measured frequency point within the measured frequency band, the first-end voltage components at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

[0013] In some possible embodiments of this disclosure, determining the open-circuit voltage components at each measured frequency point within the measured frequency band based on the open-circuit voltage of the detection system, and determining the first-terminal voltage components at each measured frequency point within the measured frequency band based on the first-terminal voltage of the conductive device under test, includes: Based on the digital phase-locked loop algorithm, the open-circuit voltage components of the open-circuit voltage at each measured frequency point in the measured frequency band are determined according to the open-circuit voltage of the detection system. Based on the digital phase-locked loop algorithm, the first-end voltage components of the first-end voltage at each measured frequency point within the measured frequency band are determined according to the first-end voltage of the conductive device under test.

[0014] According to a second aspect of the present disclosure, a conductive device detection apparatus is provided, the apparatus comprising: The parameter module is used to determine at least one parameter of the time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the testing requirements. An input module is configured to generate a time-domain trapezoidal pulse sequence based on at least one parameter of the time-domain trapezoidal pulse sequence, and input the time-domain trapezoidal pulse sequence to the conductive device under test; The detection module is used to detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, and generate an input impedance spectrum based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

[0015] In some possible implementations of this disclosure, the parameter module is used for: The repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test. Based on the detection accuracy requirements, determine the sweep bandwidth of the frequency band under test, and determine the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence based on the prime sweep bandwidth.

[0016] In some possible embodiments of this disclosure, when the parameter module is used to determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence based on the length of the conductive device under test, it is used for: Based on the length of the conductive device under test and the propagation speed of electromagnetic waves, determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence.

[0017] In some possible embodiments of this disclosure, the repetition frequency of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep resolution of the measured frequency point in the measured frequency band.

[0018] In some possible embodiments of this disclosure, the rise time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep bandwidth of the measured frequency band.

[0019] In some possible embodiments of this disclosure, the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence are related to the frequency points in the measured frequency band where the excitation amplitude is 0.

[0020] In some possible embodiments of this disclosure, when the detection module is used to detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, it is used for: The detection system is used to output the time-domain trapezoidal pulse sequence. The detection system is used to detect the open-circuit voltage and output impedance of the detection system, as well as the voltage at the beginning of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test. The open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band is determined based on the open-circuit voltage of the detection system, and the first-end voltage component of the first-end voltage at each measured frequency point within the measured frequency band is determined based on the first-end voltage of the conductive device under test. Based on the open-circuit voltage components at each measured frequency point within the measured frequency band, the first-end voltage components at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

[0021] In some possible embodiments of this disclosure, the detection module is used to determine the open-circuit voltage components at each measured frequency point within the measured frequency band based on the open-circuit voltage of the detection system, and when determining the first-terminal voltage components at each measured frequency point within the measured frequency band based on the first-terminal voltage of the conductive device under test, it is used to: Based on the digital phase-locked loop algorithm, the open-circuit voltage components of the open-circuit voltage at each measured frequency point in the measured frequency band are determined according to the open-circuit voltage of the detection system. Based on the digital phase-locked loop algorithm, the first-end voltage components of the first-end voltage at each measured frequency point within the measured frequency band are determined according to the first-end voltage of the conductive device under test.

[0022] According to a third aspect of the present disclosure, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the steps of the method described in the first aspect.

[0023] According to a fourth aspect of the present disclosure, an electronic device is provided, the electronic device including a memory and a processor, the memory being configured to store computer instructions executable on the processor, and the processor being configured to implement the method of the first aspect when executing the computer instructions.

[0024] According to a fifth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0025] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: The conductive device detection method provided in this disclosure can determine at least one parameter of a time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the detection requirements; generate a time-domain trapezoidal pulse sequence based on at least one parameter of the time-domain trapezoidal pulse sequence, and input the time-domain trapezoidal pulse sequence to the conductive device under test; detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, and generate an input impedance spectrum based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band. This method, by inputting a time-domain trapezoidal pulse sequence into the conductive device under test, excites the frequency domain response of the device under test at multiple measured frequency points within the measured frequency band, increases the amplitude of the frequency domain response, and expands the frequency range of the frequency domain response. This effectively resists electromagnetic interference in the environment, and the higher amplitude also allows for more accurate detection of weak defects at the remote end of the device, thereby effectively monitoring the remote end of the device and improving the accuracy of monitoring. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] Figure 1 This is a flowchart illustrating a conductive device detection method according to an exemplary embodiment of this disclosure; Figure 2 This is a schematic diagram of a time-domain voltage waveform shown in an exemplary embodiment of the present disclosure; Figure 3 This is a schematic diagram illustrating impedance spectrum comparison in an exemplary embodiment of this disclosure; Figure 4 This is a schematic diagram of the structure of a conductive device detection apparatus shown in an exemplary embodiment of this disclosure; Figure 5 This is a structural block diagram of an electronic device illustrated in an exemplary embodiment of the present disclosure. Detailed Implementation

[0028] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0029] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0030] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0031] Power cables possess high insulation performance and mechanical strength. With the continuous development of the power industry, their laying mileage is constantly increasing, and their proportion in power transmission and distribution lines is gradually growing, making them crucial. However, during long-term operation, factors such as cable bending and damage caused by construction, high temperature and humidity in the cable's environment, and cable vibration can all lead to defects such as insulation deterioration and water-blocking layer erosion. If these defects are not detected in time, they will eventually cause insulation breakdown, threatening the safe and stable operation of the power transmission and transformation system and causing huge economic losses. Therefore, it is necessary to conduct condition monitoring of power cables to detect defects in advance and eliminate potential hazards.

[0032] Among current condition detection methods, the traveling wave method is widely used, which can be broadly divided into two categories: time-domain reflectometry (TDR) and frequency-domain reflectometry (FDR). TDR methods extract defect information based on the time-domain characteristics of pulse signals reflected in the cable, while FDR methods primarily locate defects based on the frequency-domain characteristics of the electrical parameters at the cable's head. In field applications, the time-domain signal used by TDR methods is prone to attenuation, and when multiple defects coexist, signal aliasing is severe, making it difficult to specifically identify defects. In FDR methods, the broadband impedance spectrum (BIS) method analyzes the input impedance spectrum at the cable's head to extract impedance changes caused by defects, thereby locating cable defects. Its feasibility and final results are relatively better.

[0033] Related technologies employ impedance analyzers to obtain the broadband impedance spectrum of cables. This involves a frequency sweep method, injecting a broadband sinusoidal signal at the cable's head end, measuring the cable's input impedance as a function of frequency, and then using methods such as FFT (Fast Fourier Transform) and IT (Integral Transform) to analyze the impedance information. However, this method is difficult to effectively detect the far end of long-distance cables and is easily affected by environmental electromagnetic interference, leading to insufficient detection accuracy. For example, the output amplitude of commercial impedance analyzers is typically only around 5V. For long-distance cables, the signal attenuates significantly during transmission, making it difficult to collect weak defect signals at the far end of the cable. Furthermore, in field operation scenarios, impedance analyzers are susceptible to environmental electromagnetic interference, resulting in numerous glitches in the impedance spectrum, compromising measurement accuracy, and making the measuring equipment prone to damage.

[0034] Based on this, in a first aspect, various embodiments of this disclosure provide a method for detecting conductive devices. This method measures the broadband impedance spectrum of a conductive device (such as a power cable) using a frequency-converted time-domain pulse signal, thereby achieving effective detection of the far end of the conductive device and overcoming the influence of environmental electromagnetic interference on detection accuracy. For example, the conductive device can be a power cable.

[0035] Please refer to the appendix. Figure 1 The flowchart of the conductive device detection method is shown as an example, including steps S101 to S103.

[0036] In step S101, at least one parameter of the time-domain trapezoidal pulse sequence is determined based on the attribute parameters of the conductive device under test and the detection requirements.

[0037] For example, the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test. For instance, the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test and the electromagnetic wave propagation speed.

[0038] To reconstruct the impedance information of the entire cable length without ambiguity, the sampling point interval on the frequency axis is... (i.e., the repetition frequency of the pulse) The Nyquist criterion must be satisfied. In the cable impedance spectrum, the frequency difference between two adjacent peaks... To avoid information loss, the sampling interval... It must be at least less than or equal to half of the fluctuation period: At the same time, it must also be possible to receive the echo from the end of the cable within one pulse cycle: The pulse repetition frequency is obtained by combining the results. The conditions that need to be met are: in, The electromagnetic wave propagation speed of the conductive device under test is the speed at which the electromagnetic wave propagates within the conductive device under test. The length of the conductive device being measured; is the relative permittivity of the main insulator; c is the speed of light in a vacuum.

[0039] For example, based on the detection accuracy in the detection requirements, the sweep bandwidth of the frequency band under test is determined, and the rise duration and / or flat-top duration of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence are determined based on the prime sweep bandwidth. The rise duration and / or flat-top duration of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence are related to the frequency points within the frequency band under test where the excitation amplitude is 0.

[0040] In digital signal processing, the effective time-domain pulse width of a signal with finite bandwidth is... It is inversely proportional to the frequency domain bandwidth B: When using impedance spectroscopy to locate defects in cables, in order to distinguish two points on the cable with a spacing of... The defect requires that the time interval between the two reflected pulses generated by the defect be satisfied. Greater than the equivalent pulse width : Ultimately, the effective bandwidth and the required positioning accuracy can be obtained. Relationship: in, For positioning accuracy.

[0041] Based on the analysis of Fourier series, the spectral function of a single trapezoidal pulse... It can be represented as: Since the actual excitation has a repetition frequency of... A periodic sequence whose spectrum consists of a series of... The discrete spectral lines at that point constitute the complex amplitude of the nth harmonic, according to the Fourier series. for: The first term of the spectrum The main envelope of the spectrum is formed, and its zero-crossing point (the frequency point where the excitation amplitude is 0) appears at: The second term of the spectrum This constitutes the high-frequency amplitude modulation envelope of the spectrum. Its zero-crossing point appears at: The rise and fall times of the pulse can be adjusted according to the required effective bandwidth B. and pulse width This ensures that the pulse spectrum maintains a high amplitude within the effective bandwidth B, even if the zero-crossing point is outside the effective bandwidth B.

[0042] In step S102, a time-domain trapezoidal pulse sequence is generated based on at least one parameter of the time-domain trapezoidal pulse sequence, and the time-domain trapezoidal pulse sequence is input to the conductive device under test.

[0043] For example, nonlinear switching characteristics can be used to generate time-domain trapezoidal pulse sequences, avoiding expensive linear amplifiers, and obtaining excitation amplitudes (i.e., energy components) with higher amplitudes than sine waves in the frequency domain.

[0044] In step S103, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is detected, and an input impedance spectrum is generated based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

[0045] For example, this step can be performed as follows: First, the no-load voltage and output impedance of the detection system used to output the time-domain trapezoidal pulse sequence are detected, as well as the voltage at the beginning of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test.

[0046] Next, based on the open-circuit voltage of the detection system, the open-circuit voltage components at each measured frequency point within the measured frequency band are determined, and based on the first-terminal voltage of the conductive device under test, the first-terminal voltage components at each measured frequency point within the measured frequency band are determined. For example, based on the Digital Lock-in Algorithm (DLIA), the open-circuit voltage components at each measured frequency point within the measured frequency band are determined based on the open-circuit voltage of the detection system; based on the DLIA, the first-terminal voltage components at each measured frequency point within the measured frequency band are determined based on the first-terminal voltage of the conductive device under test.

[0047] Digital phase-locked loop (PLL) algorithms utilize the characteristic that signals and noise are uncorrelated, employing a cross-correlation detection principle to detect the signal. For the signal to be analyzed... Where t is time, T is the duration of the analysis, ω is the angular frequency of the signal, and a and b are the amplitudes of the cosine and sine components of the signal, respectively.

[0048] Construct standard cosine and sine signals with angular frequency ω': Multiply X(t) by the standard signal respectively, and then integrate the products: when When large enough, if If the frequency is 0, then a'=a, b'=b; otherwise, a'=0, b'=0. By constructing standard signals of different frequencies, the different frequency components in X(t) can be obtained.

[0049] Finally, based on the open-circuit voltage components at each measured frequency point within the measured frequency band, the first-end voltage components at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

[0050] For example, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined according to the following formula. : in, This is the no-load voltage. Let f be the no-load voltage component at frequency point f. The voltage at the beginning of the circuit is the voltage at the beginning of the circuit. Let f be the voltage component at the beginning of the voltage range. This is the output impedance.

[0051] Change the repetition frequency of the pulse voltage signal This changes the fundamental frequency of the sinusoidal signal obtained from the Fourier series decomposition; simultaneously, it changes the rise time of the pulse voltage. With the duration of the flat top This also alters the magnitude of the frequency components obtained from the decomposition. Therefore, by injecting pulse signals with varying repetition frequencies and rise times several times and integrating the results, the impedance spectrum of the cable within the desired frequency range can be obtained completely. Through the above steps, a broadband impedance spectrum of power cables can be measured based on variable frequency time-domain pulse signals without the aid of commercial equipment such as impedance analyzers, providing an effective and practical technical method for obtaining cable impedance spectra.

[0052] The conductive device detection method provided in this disclosure can determine at least one parameter of a time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the detection requirements; generate a time-domain trapezoidal pulse sequence based on at least one parameter of the time-domain trapezoidal pulse sequence, and input the time-domain trapezoidal pulse sequence to the conductive device under test; detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, and generate an input impedance spectrum based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band. This method, by inputting a time-domain trapezoidal pulse sequence into the conductive device under test, excites the frequency domain response of the device under test at multiple measured frequency points within the measured frequency band, and increases the amplitude and expands the frequency range of the frequency domain response. This effectively resists electromagnetic interference in the environment, and the higher amplitude also allows for more accurate detection of weak defects at the remote end of the device, thereby effectively monitoring the remote end of the device and improving the accuracy of monitoring.

[0053] This method addresses the problem that commercially available equipment such as impedance analyzers are easily damaged by electromagnetic interference during field cable measurements. It also solves the problem that frequency sweep methods in related technologies often have low signal amplitudes, making long-distance transmission difficult and resulting in the inability to detect weak defect signals. In other words, this method applies a time-domain pulse voltage with varying repetition frequency, rise time, and pulse width, and processes the reflected waveform to extract its frequency components, thus obtaining the broadband impedance spectrum of the cable. The higher signal amplitude of this measurement method effectively resists electromagnetic interference and allows for more accurate detection of weak defects at the cable's distal end, exhibiting higher sensitivity. This patent provides an efficient solution for obtaining the broadband impedance spectrum of cable systems and further enabling defect detection.

[0054] A test system was set up in the laboratory. The cable under test was an 80m long, defect-free RG58 cable. To verify the accuracy of the broadband impedance spectrum obtained by the proposed test method, the broadband impedance spectrum measured based on time-domain pulse signals was compared with the results measured by an impedance analyzer of model TH2851-30. The original time-domain voltage waveforms of the cable under test when disconnected and connected are as follows: Figure 2 The proposed method and the impedance spectrum of the impedance analyzer are compared as follows: Figure 3 .

[0055] Experimental results show that, within a 30MHz frequency range, the proposed method for measuring the impedance spectrum of power cables based on variable-frequency time-domain pulse signals agrees well with the measurement results of commercial impedance analyzers. Furthermore, the proposed method can obtain impedance spectra over a wider frequency range. In practical field applications, the impedance spectrum measured by impedance analyzers is susceptible to interference from background voltage due to the limited amplitude of only 5V, resulting in reduced accuracy. The variable-frequency time-domain pulse signal measurement method, however, can enhance anti-interference capabilities by increasing the amplitude of the output voltage, leading to more accurate broadband impedance spectrum measurements. Moreover, when using the broadband impedance spectrum obtained by the proposed method for defect location, it will exhibit better response to weak defects, thereby improving the sensitivity of defect identification and location.

[0056] The repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence will be described next. By adjusting the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence, the sweep resolution of the measured frequency points within the measured frequency band can be adjusted.

[0057] Since the time-domain trapezoidal pulse sequence has a repetition frequency of... A periodic sequence whose spectrum consists of a series of... The discrete spectral lines at the specified points. According to the Fourier series, the nth harmonic frequency of the time-domain trapezoidal pulse sequence is... discrete amplitude at for: As shown in the above equation, the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is negatively correlated with the sweep resolution of the measured frequency points within the measured frequency band. The repetition frequency determines the density of impedance observation points in the frequency domain and the spectral line spacing. Reduce This allows for a finer spectral density, thus improving frequency resolution. Sweep resolution is the sweep step size, which is the interval between adjacent measured frequencies. A finer density of measured frequencies can be obtained by reducing the repetition frequency, i.e., reducing the sweep step size.

[0058] The rise duration of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence will be described next. By adjusting the rise duration of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence, the sweep bandwidth of the measured frequency band can be adjusted.

[0059] The rise time of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is negatively correlated with the sweep bandwidth of the measured frequency band. By shortening the rise time, the edge steepness can be compressed, pushing the envelope zero point to extremely high frequencies, ensuring... The amplitude response is smooth within the sweep frequency range.

[0060] The second term of the spectrum This constitutes the high-frequency amplitude modulation envelope of the spectrum. Its zero-crossing point (the frequency at which the excitation amplitude is 0) appears at: This determines the equivalent bandwidth of the frequency sweep. The steeper the time-domain edge, the slower the frequency-domain envelope decreases. By... Compression to the nanosecond level essentially expands the effective dynamic range of the excitation signal, ensuring that the energy amplitude in the high-frequency band is higher than the background noise benchmark.

[0061] Next, we will introduce the flat-top duration of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence. By adjusting the flat-top duration of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence, the frequency point with an excitation amplitude of 0 in the measured frequency band can be adjusted.

[0062] The first term of the spectrum The main envelope of the spectrum is formed, and its zero-crossing point (i.e., the frequency point where the excitation amplitude is 0) appears at: Flat-top duration The energy concentration of the main lobe of the spectrum is determined by adjusting the peak duration. In essence, this corresponds to "frequency domain shifting," which allows for the artificial movement of the blind zone position (i.e., the frequency point with an excitation amplitude of 0) to ensure that the target frequency point (i.e. the frequency point that is to be detected) receives a sufficient excitation amplitude.

[0063] The trapezoidal pulse spectrum consists of two... Superposition mapping of functions. This disclosure achieves this through time-domain co-regulation. (Control step size) (Control bandwidth) and (By controlling the energy blind zone offset), it is theoretically possible to synthesize an equivalent swept spectrum with flat and continuous amplitude within a specific frequency band.

[0064] In some possible embodiments of this disclosure, the time-domain trapezoidal pulse sequence can be input to the conductive device under test in the following manner: after adjusting the time-domain parameters of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence each time, the time-domain trapezoidal pulse sequence is input to the conductive device under test until the time-domain parameters are adjusted a preset number of times, wherein the time-domain parameters include repetition frequency, rise duration and flat-top duration, and at least one of the repetition frequency, rise duration and flat-top duration is adjusted each time the time-domain parameters are adjusted.

[0065] In other words, within a detection cycle, multiple sets of time-domain trapezoidal pulses with different time-domain parameters (at least one of the rise time, repetition frequency, and flat-top duration of the different time-domain parameters is different) can be emitted cyclically.

[0066] For example, two sets of timing trapezoidal pulses with flat-top durations of the first and second durations are alternately transmitted. The rise duration and repetition frequency of the two sets of timing trapezoidal pulses are the same. Since the zero-point position varies... The movement of multiple signals creates a complementary peak-to-trough pattern in the frequency domain, with the zero-crossing points (frequency points where the excitation amplitude is 0) and peaks of the two sets of time-sequential trapezoidal pulses being complementary.

[0067] Based on the time-domain trapezoidal pulse sequence input method in this embodiment, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band can be detected in the following manner: First, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is detected after the time-domain trapezoidal pulse sequence with each time-domain parameter is injected. In other words, after each injection of a set of time-domain trapezoidal pulse sequences, the input impedance at each measured frequency point within the measured frequency band is collected; after injecting multiple sets of time-domain trapezoidal pulse sequences with different time-domain parameters, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band after the time-domain trapezoidal pulse sequence with each time-domain parameter is injected is obtained. For example, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band after the time-domain trapezoidal pulse sequence with each time-domain parameter is injected can be obtained based on the digital phase-locked loop algorithm-based method described in the previous embodiments. That is, the input impedance of the device under test at each measured frequency point within the measured frequency band is obtained after the time-domain trapezoidal pulse sequence with a certain time-domain parameter is injected into the device under test in the following manner: the open-circuit voltage and output impedance of the detection system used to output the time-domain trapezoidal pulse sequence are detected, as well as the first-terminal voltage of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test; based on the digital phase-locked loop algorithm, the open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band is determined according to the open-circuit voltage of the detection system, and based on the digital phase-locked loop algorithm, the first-terminal voltage component of the first-terminal voltage at each measured frequency point within the measured frequency band is determined according to the first-terminal voltage of the conductive device under test; based on the open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band, the first-terminal voltage component of the first-terminal voltage at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

[0068] Next, for each frequency point within the measured frequency band, the total input impedance of the measured frequency point is determined based on the input impedance of the conductive device under test at that frequency point after the time-domain trapezoidal pulse sequence of each time-domain parameter is injected.

[0069] The first step is to determine the weight of each time-domain parameter based on the excitation amplitude at the measured frequency point after the time-domain trapezoidal pulse sequence with each time-domain parameter is injected into the conductive device under test. Taking the injection of M sets of time-domain trapezoidal pulse sequences with different time-domain parameters into the conductive device under test as an example, the weight of each time-domain parameter can be determined at each measured frequency point. At this point, by comparing the excitation amplitude under different parameters in group M. The confidence weights are calculated based on the energy intensity of the excitation signal at each frequency point. The i-th group of time-domain trapezoidal pulse sequences is defined at frequency points... Confidence weight at the point The magnitude of the excitation signal at that point is a power function: For the calculated i-th group of time-domain trapezoidal pulses in The discrete amplitude magnitude at the point, k is the sensitivity adjustment coefficient (usually taken as...). When k is large, the system will greatly suppress measurement data near the energy zero point, causing the final result to be biased towards high-energy (high signal-to-noise ratio) data.

[0070] The second step involves weighting the input impedance of the conductive device under test at the measured frequency point after the time-domain trapezoidal pulse sequence of each time-domain parameter is injected, according to the weights of each time-domain parameter. The summation result is then determined as the total input impedance at that measured frequency point. For example, its total input impedance As shown in the following formula: in This is the input impedance calculated through sampling under the i-th set of time-domain trapezoidal pulse parameters. This dynamic weight allocation strategy can fundamentally eliminate the inherent inaccuracies in single-pulse measurements.

[0071] According to a second aspect of the embodiments of this disclosure, a conductive device detection apparatus is provided. Please refer to the attached drawing. Figure 4 The device includes: Parameter module 401 is used to determine at least one parameter of the time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the detection requirements; Input module 402 is used to generate a time-domain trapezoidal pulse sequence based on at least one parameter of the time-domain trapezoidal pulse sequence, and input the time-domain trapezoidal pulse sequence to the conductive device under test; The detection module 403 is used to detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, and generate an input impedance spectrum based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

[0072] In some possible implementations of this disclosure, the parameter module is used for: The repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test. Based on the detection accuracy requirements, determine the sweep bandwidth of the frequency band under test, and determine the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence based on the prime sweep bandwidth.

[0073] In some possible embodiments of this disclosure, when the parameter module is used to determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence based on the length of the conductive device under test, it is used for: Based on the length of the conductive device under test and the propagation speed of electromagnetic waves, determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence.

[0074] In some possible embodiments of this disclosure, the repetition frequency of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep resolution of the measured frequency point in the measured frequency band.

[0075] In some possible embodiments of this disclosure, the rise time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep bandwidth of the measured frequency band.

[0076] In some possible embodiments of this disclosure, the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence are related to the frequency points in the measured frequency band where the excitation amplitude is 0.

[0077] In some possible embodiments of this disclosure, when the detection module is used to detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, it is used for: The detection system is used to output the time-domain trapezoidal pulse sequence. The detection system is used to detect the open-circuit voltage and output impedance of the detection system, as well as the voltage at the beginning of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test. The open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band is determined based on the open-circuit voltage of the detection system, and the first-end voltage component of the first-end voltage at each measured frequency point within the measured frequency band is determined based on the first-end voltage of the conductive device under test. Based on the open-circuit voltage components at each measured frequency point within the measured frequency band, the first-end voltage components at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

[0078] In some possible embodiments of this disclosure, the detection module is used to determine the open-circuit voltage components at each measured frequency point within the measured frequency band based on the open-circuit voltage of the detection system, and when determining the first-terminal voltage components at each measured frequency point within the measured frequency band based on the first-terminal voltage of the conductive device under test, it is used to: Based on the digital phase-locked loop algorithm, the open-circuit voltage components of the open-circuit voltage at each measured frequency point in the measured frequency band are determined according to the open-circuit voltage of the detection system. Based on the digital phase-locked loop algorithm, the first-end voltage components of the first-end voltage at each measured frequency point within the measured frequency band are determined according to the first-end voltage of the conductive device under test.

[0079] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments of the method in the first aspect, and will not be elaborated upon here.

[0080] According to a third aspect of the present disclosure, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the steps of the method described in the first aspect.

[0081] According to the fourth aspect of the embodiments of this disclosure, please refer to the appendix. Figure 5 An electronic device is provided, the electronic device including a memory and a processor, the memory being used to store computer instructions executable on the processor, and the processor being used to implement the method of the first aspect when executing the computer instructions.

[0082] According to a fifth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0083] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0084] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for detecting conductive devices, characterized in that, The method includes: Based on the property parameters of the conductive device under test and the testing requirements, determine at least one parameter of the time-domain trapezoidal pulse sequence; A time-domain trapezoidal pulse sequence is generated based on at least one parameter of the time-domain trapezoidal pulse sequence, and the time-domain trapezoidal pulse sequence is input to the conductive device under test; The input impedance of the conductive device under test at each measured frequency point within the measured frequency band is detected, and an input impedance spectrum is generated based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

2. The method for detecting conductive devices according to claim 1, characterized in that, The determination of at least one parameter of the time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the testing requirements includes: The repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence is determined based on the length of the conductive device under test. Based on the detection accuracy requirements, determine the sweep bandwidth of the frequency band under test, and determine the rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence based on the prime sweep bandwidth.

3. The conductive device detection method according to claim 2, characterized in that, Determining the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence based on the length of the conductive device under test includes: Based on the length of the conductive device under test and the propagation speed of electromagnetic waves, determine the repetition frequency of the time-domain trapezoidal pulses within the time-domain trapezoidal pulse sequence.

4. The method for detecting conductive devices according to claim 2, characterized in that, The repetition frequency of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep resolution of the measured frequency points within the measured frequency band.

5. The method for detecting conductive devices according to claim 2, characterized in that, The rise time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence is negatively correlated with the sweep bandwidth of the measured frequency band.

6. The method for detecting conductive devices according to claim 2, characterized in that, The rise time and / or flat-top time of the time-domain trapezoidal pulses in the time-domain trapezoidal pulse sequence are related to the frequency points in the measured frequency band where the excitation amplitude is 0.

7. The method for detecting conductive devices according to claim 1, characterized in that, The detection of the input impedance of the conductive device under test at each measured frequency point within the measured frequency band includes: The detection system is used to output the time-domain trapezoidal pulse sequence. The detection system is used to detect the open-circuit voltage and output impedance of the detection system, as well as the voltage at the beginning of the conductive device under test after the detection system inputs the time-domain trapezoidal pulse sequence to the conductive device under test. The open-circuit voltage component of the open-circuit voltage at each measured frequency point within the measured frequency band is determined based on the open-circuit voltage of the detection system, and the first-end voltage component of the first-end voltage at each measured frequency point within the measured frequency band is determined based on the first-end voltage of the conductive device under test. Based on the open-circuit voltage components at each measured frequency point within the measured frequency band, the first-end voltage components at each measured frequency point within the measured frequency band, and the output impedance of the detection system, the input impedance of the conductive device under test at each measured frequency point within the measured frequency band is determined.

8. The method for detecting conductive devices according to claim 7, characterized in that, The step of determining the open-circuit voltage component at each measured frequency point within the measured frequency band based on the open-circuit voltage of the detection system, and determining the first-terminal voltage component at each measured frequency point within the measured frequency band based on the first-terminal voltage of the conductive device under test, includes: Based on the digital phase-locked loop algorithm, the open-circuit voltage components of the open-circuit voltage at each measured frequency point in the measured frequency band are determined according to the open-circuit voltage of the detection system. Based on the digital phase-locked loop algorithm, the first-end voltage components of the first-end voltage at each measured frequency point within the measured frequency band are determined according to the first-end voltage of the conductive device under test.

9. A conductive equipment detection device, characterized in that, The device includes: The parameter module is used to determine at least one parameter of the time-domain trapezoidal pulse sequence based on the attribute parameters of the conductive device under test and the testing requirements. An input module is configured to generate a time-domain trapezoidal pulse sequence based on at least one parameter of the time-domain trapezoidal pulse sequence, and input the time-domain trapezoidal pulse sequence to the conductive device under test; The detection module is used to detect the input impedance of the conductive device under test at each measured frequency point within the measured frequency band, and generate an input impedance spectrum based on the input impedance of the conductive device under test at each measured frequency point within the measured frequency band.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computational program / instructions are executed by the processor, they implement the steps of the method described in any one of claims 1 to 8.

11. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory being used to store computer instructions executable on the processor, and the processor being used to implement the method of any one of claims 1 to 8 when executing the computer instructions.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method of any one of claims 1 to 8.

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