Electric field and magnetic field synchronous acquisition power transmission line fault traveling wave detection method

Abstract

The invention discloses a power transmission line fault traveling wave detection method for synchronous acquisition of an electric field and a magnetic field, and belongs to the technical field of power system power transmission line fault detection and positioning. Comprising the following steps: S1, placing an electric field sensor below a power transmission line, placing a magnetic field sensor near a tower, and synchronously measuring an electromagnetic field signal; s2, calculating a conversion coefficient through finite element simulation, and inverting the measured electromagnetic field signal; s3, connecting the voltage traveling wave and the current traveling wave obtained by inversion to the same high-speed acquisition card, and performing calibration through a GPS time service module; and S4, identifying the first voltage traveling wave and the reflected voltage traveling wave according to the characteristics that the phases of the first voltage traveling wave and the current traveling wave are in the same direction and the phases of the reflected voltage traveling wave and the current traveling wave are in opposite directions, and completing fault traveling wave detection. By adopting the method, non-contact acquisition can be realized so as to reduce line interference and safety risk, GPS time service guarantees traveling wave synchronism, head waves and reflected waves are accurately identified, and rapid positioning and disposal of faults are assisted.

Description

Technical Field

[0001] This invention relates to the field of power system transmission line fault detection and location technology, and in particular to a method for detecting traveling waves of transmission line faults by synchronously acquiring electric and magnetic fields. Background Technology

[0002] Ultra-high voltage direct current (UHVDC) transmission lines are characterized by long transmission distances and significant variations in terrain and climate along their routes, placing extremely high demands on the ability to rapidly isolate, restore, analyze causes, and prevent faults. Current fault location methods for UHVDC transmission lines primarily rely on dual-end ranging. This method calculates the fault location by measuring the arrival time difference of the traveling waves at both ends of the voltage line. While this method offers high accuracy, it is limited by the sensing technology of the ranging devices within the converter station. This can lead to situations where one end of the device fails to operate or malfunctions, resulting in the ranging function becoming ineffective and failing to meet the reliability requirements of operation and maintenance. Single-end ranging, as a backup solution after the failure of double-end ranging, only requires the normal start of one ranging device to achieve fault location, which is more in line with actual operation and maintenance needs. However, the current technology has two major problems: First, the amplitude of the fault voltage traveling wave will attenuate and the rate of change will decrease during the propagation process. The reflected voltage traveling wave will travel a longer distance and attenuate more significantly. When it reaches the converter station, the amplitude is weak, which affects the ranging accuracy. Second, the pulse interference generated by the operation of the converter valve is similar to the waveform of the fault traveling wave, making it difficult for the measurement system to distinguish between the effective fault traveling wave and the interference signal. Ultimately, the deviation between the single-end ranging result and the actual fault location can be tens or even hundreds of kilometers.

[0003] Therefore, there is an urgent need for a method for detecting traveling wave faults in transmission lines that can provide high-quality raw data for fault location and improve the reliability and accuracy of single-end ranging. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting traveling waves of transmission line faults by synchronously acquiring electric and magnetic fields, thereby solving the above-mentioned technical problems.

[0005] To achieve the above objectives, this invention provides a method for detecting traveling waves of transmission line faults by synchronously acquiring electric and magnetic fields, comprising the following steps: S1. Electromagnetic field synchronous acquisition deployment: Place the electric field sensor below the transmission line and the magnetic field sensor in the vicinity of the tower to simultaneously measure the electromagnetic field signal; S2. Traveling wave inversion calculation: The conversion coefficients of voltage and electric field, and current and magnetic field are calculated by finite element simulation. Based on the conversion coefficients, the measured electromagnetic field signals are inverted to obtain voltage traveling waves and current traveling waves. S3. Signal Synchronization and Time Synchronization: The voltage traveling wave and current traveling wave obtained by inversion are connected to the same high-speed acquisition card, and the acquisition time is calibrated by the GPS time synchronization module to realize the synchronous acquisition of voltage traveling wave and current traveling wave. S4. Traveling wave identification based on phase relationship: Based on the characteristics that the initial voltage traveling wave and the current traveling wave are in the same phase and the reflected voltage traveling wave and the current traveling wave are in opposite phase, the initial voltage traveling wave and the reflected voltage traveling wave are identified to complete the fault traveling wave detection.

[0006] Preferably, S1 specifically includes: S11. Select a capacitive electric field sensor to collect the electric field signal corresponding to the voltage traveling wave. A Hall effect magnetic field sensor was selected to collect the magnetic field signal corresponding to the traveling current wave. ; S12. Deploy the electric field sensor directly below the transmission line conductor, and deploy the magnetic field sensor on the tower body, the grounding down conductor and its adjacent area. S13. Adjust the sensors to ensure that the electric field sensor and magnetic field sensor have the same acquisition frequency, and synchronously set a unified acquisition trigger threshold and trigger timing to ensure that the two sensors synchronously acquire the space electric field signal caused by the fault. and magnetic field signals .

[0007] Preferably, S2 specifically includes: S21. Using COMSOL software, a simulation model is constructed in proportion to the actual parameters of the transmission line. The actual parameters include conductor type, tower height, conductor distance from the ground, and number of split conductors. At the same time, the material properties of air, conductor, and tower are set. S22. Use the electrostatics module of COMSOL software to simulate the electric field distribution in the space beneath the transmission line, and obtain the conversion factor between the spatial electric field and the line voltage through the correspondence between electric field strength and line voltage. The COMSOL software's current module is used to simulate the spatial magnetic field distribution near the tower. The conversion factor between the spatial magnetic field and the line current is obtained through the correspondence between magnetic field strength and line current. ; S23, Based on conversion factor and The fault voltage traveling wave signal is obtained through traveling wave inversion calculation. and current traveling wave signal Its formula is: .

[0008] Preferably, S3 specifically includes: S31. The voltage traveling wave signal obtained from the inversion... and current traveling wave signal Different channels of the same high-speed acquisition card are connected to the signal input paths, and the impedances of the two signal input paths are matched to achieve multi-channel synchronous sampling. S32. Employs analog level trigger mode with a preset trigger threshold; when a voltage traveling wave signal... or current traveling wave signal When the signal amplitude of the channel exceeds the threshold, the high-speed acquisition card is triggered to start acquisition synchronously across all channels. S33. Connect to the GPS timing module to calibrate the signal acquisition time of the high-speed acquisition card, ensuring the voltage traveling wave signal... and current traveling wave signal Data collected under the same time reference; S34. The input signal is noise-suppressed by the signal conditioning circuit built into the acquisition card, and the analog signal is converted into a digital signal by the A / D converter and synchronously stored in the storage unit of the acquisition card.

[0009] Preferably, S4 specifically includes: S41. The synchronously acquired voltage traveling wave signal and current traveling wave signal The wavefront detection algorithm converts the signals into a voltage pulse sequence A and a current pulse sequence B, respectively, with time stamps and phase information. The phase information is calculated by performing a Fast Fourier Transform on the voltage and current traveling wave digital signals, using the following formula: ; in, The time-domain sequence of a traveling wave digital signal. This indicates the Fast Fourier Transform operation. Indicates the argument of a complex number. This refers to the phase value; S42. Starting from the first pulse of voltage pulse sequence A, extract the time stamp of that pulse. ,examine Does the current pulse sequence B at time point B contain a pulse signal? If it does and both pulses are in the same phase, mark this pulse as the first voltage traveling wave and record the wavefront time. And denote this pulse as the first pulse in sequence A. pulses, of which When there is no pulse signal or the two pulses are out of phase, the pulse is determined to be an interference signal, and the second, third, and subsequent pulses of sequence A are checked. pulses, of which The initial total number of pulses for sequence A is used until the first voltage traveling wave is identified. If no pulse signal is identified after traversing all pulses, the currently acquired signal is determined to be an invalid interference signal, and the detection process is terminated. S43, taking the pulse corresponding to the first voltage traveling wave as the... The pulse is used to sequentially check the first pulse of sequence A. 1 pulse, of which Given the total number of pulses in voltage pulse sequence A, extract the first pulse. Time markers for each pulse ,and Check sequence B in Check if a pulse signal exists at any given time; if a pulse signal exists and the two pulses are out of phase, mark the pulse as a reflected voltage traveling wave and record its wavefront time. When there is no pulse signal or the two pulses are out of phase, the pulse is determined to be an interference signal, and the next pulse is checked. S44. After the traversal is complete, output the wavefront time of the first voltage traveling wave for all marked values. Wavefront time of reflected voltage traveling wave Complete the traveling wave detection for the fault.

[0010] Preferably, the boundary conditions of the COMSOL simulation model in S21 are set as follows: the transmission line conductors are subjected to the rated operating voltage, the towers and the ground are set to grounding potential, and the air domain boundary is set to far-field conditions to simulate an infinite space environment.

[0011] Preferably, in the signal conditioning circuit of S34, the resistor-capacitor parameters of the low-pass filter circuit are based on the cutoff frequency. The design employs an operational amplifier with a high common-mode rejection ratio to ensure both noise suppression and linear signal amplification.

[0012] Preferably, the high-speed acquisition card in S34 has a built-in A / D converter with 16 bits or more to ensure the accuracy and speed of converting weak traveling wave analog signals to digital signals.

[0013] Preferably, the wavefront detection algorithm in S41 specifically involves: processing the traveling wave digital signal... Perform sliding window processing to calculate the signal amplitude difference between adjacent windows. Its formula is: ; when At that time, the judgment The time is the wavefront position, and the signal at that time is extracted as a pulse in the pulse sequence, where, This represents the standard deviation of the signal amplitude during normal operation.

[0014] Preferably, the conversion factor is calculated in S22. At that time, the average electric field strength at the deployment location of the electric field sensor is taken. Apply voltage to the line The ratio is ; Calculate the conversion factor At that time, the average magnetic field strength at the deployment location of the magnetic field sensor is taken. Current flows through the line The ratio is ,in, and The integration region is calculated using the region integration function of COMSOL simulation results, and the integration region represents the actual spatial range of the sensor deployment.

[0015] Therefore, the present invention employs the above-mentioned method for detecting traveling waves of transmission line faults by synchronously acquiring electric and magnetic fields, which has the following beneficial effects: 1. Capacitive electric field sensors and Hall effect magnetic field sensors are used. Both types of sensors are technologically mature and relatively low in cost. They are also non-contact measurements, which do not require direct electrical connection with the transmission line, reducing the impact on the normal operation of the line and lowering the safety risks and costs of installation and maintenance.

[0016] 2. Multi-channel synchronous acquisition of fault voltage and current traveling wave signals is used, and GPS is used to achieve accurate calibration of the acquisition time. This solves the time synchronization problem of voltage and current traveling wave measurement at the hardware level and provides a reliable time reference for phase relationship analysis.

[0017] 3. By utilizing the phase relationship between voltage traveling waves and current traveling waves during line faults, a synchronous observation method for current traveling waves and voltage traveling waves is proposed, which solves the problem of accurately identifying reflected voltage traveling waves from a large number of interference voltage signals and improves the reliability of distance measurement.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the transmission line fault traveling wave detection system with synchronous electromagnetic field acquisition according to the present invention. Figure 2 This is a schematic diagram showing the placement of the electric and magnetic field sensors of the present invention; Figure 3 This is a schematic diagram of the process for synchronous acquisition of voltage and current traveling wave signals in this invention; Figure 4 This is a schematic diagram of the voltage and current traveling wave signal synchronous acquisition module of the present invention; Figure 5 This is a schematic diagram illustrating the determination of reflected voltage traveling wave signals in a voltage traveling wave pulse sequence based on phase relationship according to the present invention. Figure 6 This is a flowchart illustrating the reflected voltage traveling wave identification algorithm of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only for explaining the embodiments of the present invention and are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of this application. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0021] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or server that includes a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] like Figures 1-6 As shown, a method for detecting traveling waves in transmission line faults using synchronous acquisition of electric and magnetic fields includes the following steps: S1, Electromagnetic field synchronous acquisition deployment: An electric field sensor is placed below the transmission line, and a magnetic field sensor is placed near the tower. Electromagnetic field signals are measured synchronously to achieve non-contact signal acquisition, avoiding interference from direct electrical connections to the normal operation of the line and reducing installation and maintenance safety risks; S2, Traveling wave inversion calculation: The conversion coefficients between voltage and electric field, and between current and magnetic field are calculated using finite element simulation. Based on these conversion coefficients, the measured electromagnetic field signals are inverted to obtain voltage and current traveling waves, ensuring the accuracy of the traveling wave signal inversion and providing a basis for subsequent synchronous acquisition. Step 1: High-quality raw data acquisition; S3: Signal synchronization and timing: The voltage and current traveling waves obtained by inversion are connected to the same high-speed acquisition card, and the acquisition time is calibrated by the GPS timing module to realize the synchronous acquisition of voltage and current traveling waves, providing a reliable time reference for phase relationship analysis; S4: Traveling wave identification based on phase relationship: Based on the characteristics that the initial voltage and current traveling waves are in the same phase and the reflected voltage and current traveling waves are in opposite phase, the initial voltage traveling wave and the reflected voltage traveling wave are identified, interference signals are accurately eliminated and weak reflected traveling waves are identified, and fault traveling wave detection is completed to improve the accuracy of traveling wave identification.

[0024] Specifically, S1 includes: S11, using a capacitive electric field sensor to acquire the electric field signal corresponding to the voltage traveling wave. A Hall effect magnetic field sensor was selected to collect the magnetic field signal corresponding to the traveling current wave. S12. Deploy the electric field sensor directly beneath the transmission line conductor, and the magnetic field sensor on the tower body, grounding down conductor, and their adjacent area, ensuring the sensors are in the optimal signal acquisition area to improve the effectiveness of electromagnetic field signal acquisition; S13. Debug the sensors to ensure the electric field and magnetic field sensors have the same acquisition frequency, and synchronously set a unified acquisition trigger threshold and trigger timing to avoid signal asynchrony due to parameter differences, ensuring that both sensors synchronously acquire the spatial electric field signal caused by the fault. and magnetic field signals .

[0025] S2 specifically includes: S21, using COMSOL software to construct a simulation model proportionally to the actual parameters of the transmission line. These parameters include conductor type, tower height, conductor distance from ground, and number of split conductors. The material properties of air, conductors, and towers are also set. S22, using the electrostatics module of COMSOL software to simulate the electric field distribution in the space beneath the transmission line, and obtaining the conversion factor between the spatial electric field and the line voltage through the correspondence between electric field strength and line voltage. The COMSOL software's current module is used to simulate the spatial magnetic field distribution near the tower. The conversion factor between the spatial magnetic field and the line current is obtained through the correspondence between magnetic field strength and line current. S23, Based on conversion factor and The fault voltage traveling wave signal is obtained through traveling wave inversion calculation. and current traveling wave signal Linear conversion can avoid signal distortion and ensure the quality of traveling wave signals. The formula is as follows: .

[0026] S3 specifically includes: S31, the voltage traveling wave signal obtained from the inversion. and current traveling wave signal Different channels of the same high-speed acquisition card are connected to the signals respectively, and the impedances of the two signal input paths are matched to achieve multi-channel synchronous sampling; S32, adopts analog level trigger mode, preset trigger threshold, when voltage traveling wave signal or current traveling wave signal When the signal amplitude of the channel exceeds the threshold, the high-speed acquisition card is triggered to synchronously start acquisition across all channels; S33, connect to the GPS timing module to calibrate the signal acquisition time of the high-speed acquisition card, ensuring the voltage traveling wave signal... and current traveling wave signal Data is collected under the same time reference; S34, the signal conditioning circuit built into the acquisition card suppresses noise and improves the signal-to-noise ratio. The analog signal is converted into a digital signal by the A / D converter to ensure the accuracy of the signal conversion. The data is then synchronously stored in the storage unit of the acquisition card to ensure data traceability.

[0027] S4 specifically includes: S41, synchronously acquiring the voltage traveling wave signal. and current traveling wave signal The wavefront detection algorithm converts the signals into a voltage pulse sequence A and a current pulse sequence B, respectively, with time stamps and phase information. The phase information is calculated by performing a Fast Fourier Transform on the voltage and current traveling wave digital signals, using the following formula: ; in, The time-domain sequence of a traveling wave digital signal. This indicates the Fast Fourier Transform operation. Indicates the argument of a complex number. For phase value; S42, starting from the first pulse of voltage pulse sequence A, extract the time stamp of that pulse. ,examine Does the current pulse sequence B at time point B contain a pulse signal? If it does and both pulses are in the same phase, mark this pulse as the first voltage traveling wave and record the wavefront time. And denote this pulse as the first pulse in sequence A. pulses, of which When there is no pulse signal or the two pulses are out of phase, the pulse is determined to be an interference signal, and the second, third, and subsequent pulses of sequence A are checked. pulses, of which The initial total number of pulses in sequence A is used until the first voltage traveling wave is identified; if no pulse signal is identified after traversing all pulses, the currently acquired signal is determined to be an invalid interference signal, and the detection process is terminated; S43, the pulse corresponding to the first voltage traveling wave is taken as the... The pulse is used to sequentially check the first pulse of sequence A. 1 pulse, of which Given the total number of pulses in voltage pulse sequence A, extract the first pulse. Time markers for each pulse ,and Check sequence B in Check if a pulse signal exists at any given time; if a pulse signal exists and the two pulses are out of phase, mark the pulse as a reflected voltage traveling wave and record its wavefront time. When there is no pulse signal or the two pulses are out of phase, the pulse is determined to be an interference signal, and the next pulse is checked; S44, after the traversal is completed, the wavefront time of the first voltage traveling wave of all marked pulses is output. Wavefront time of reflected voltage traveling wave Complete the traveling wave detection for the fault.

[0028] Furthermore, the boundary conditions of the COMSOL simulation model in S21 are set as follows: the transmission line conductors are subjected to the rated operating voltage, the towers and ground are set to grounding potential, and the air domain boundary is set to far-field conditions to simulate an infinite space environment. This simulates a real operating scenario to avoid simulation errors caused by boundary effects and ensure the reliability of the simulation results. In the signal conditioning circuit in S34, the RC parameters of the low-pass filter circuit are set according to the cutoff frequency. The operational amplifier circuit in the design employs a high common-mode rejection ratio (CMRR) operational amplifier to ensure both noise suppression and linear signal amplification, providing dual protection for signal quality. The high-speed acquisition card in S34 has a built-in A / D converter with 16 bits or more to ensure the accuracy and speed of converting weak traveling wave analog signals to digital signals, balancing real-time detection and accuracy. The wavefront detection algorithm in S41 specifically involves: processing the traveling wave digital signal... Perform sliding window processing to calculate the signal amplitude difference between adjacent windows. Its formula is: ; when At that time, the judgment The time is the wavefront position, and the signal at that time is extracted as a pulse in the pulse sequence, where, The standard deviation of the signal amplitude during normal operation is used to effectively distinguish faulty wavefronts from normal fluctuations through threshold determination, thereby improving wavefront detection sensitivity. The conversion factor is calculated in S22. At that time, the average electric field strength at the deployment location of the electric field sensor is taken. Apply voltage to the line The ratio is ; Calculate the conversion factor At that time, the average magnetic field strength at the deployment location of the magnetic field sensor is taken. Current flows through the line The ratio is ,in, and The integration region is calculated using the regional integration function of COMSOL simulation results. The integration region is the actual spatial range of the sensor deployment. Regional integration can avoid the influence of single-point signal fluctuations and ensure the stability of the conversion factor calculation.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for power line fault traveling wave detection by electric field and magnetic field synchronous acquisition, characterized in that: The method comprises the following steps: S1, electromagnetic field synchronous acquisition deployment: placing electric field sensors under the power transmission line and magnetic field sensors in the vicinity of the tower to synchronously measure electromagnetic field signals; S2, forward wave inversion calculation: calculating the conversion coefficients of voltage and electric field and current and magnetic field through finite element simulation, and inversely calculating voltage forward waves and current forward waves based on the conversion coefficients; S3, signal synchronization and time service: connecting the inversely calculated voltage forward waves and current forward waves to the same high-speed acquisition card, calibrating the acquisition time through a GPS time service module, and realizing synchronous acquisition of voltage forward waves and current forward waves; S4, forward wave identification based on phase relationship: identifying the first voltage forward wave and the reflected voltage forward wave according to the characteristics that the phase of the first voltage forward wave and the current forward wave is in the same direction and the phase of the reflected voltage forward wave and the current forward wave is in the opposite direction, and completing fault forward wave detection.

2. The method of claim 1, wherein the method further comprises: S1 specifically comprises: S11, selecting a capacitive electric field sensor to collect an electric field signal corresponding to a voltage traveling wave ; S12, selecting a Hall magnetic field sensor to collect a magnetic field signal corresponding to a current traveling wave ; S12, deploying electric field sensors directly below the power transmission line conductor and deploying magnetic field sensors in the tower body, the grounding down lead and the adjacent area thereof; S13, debugging sensor makes the collection frequency of the electric field sensor and the magnetic field sensor consistent, and synchronously sets uniform collection trigger threshold and trigger timing, ensuring that the two sensors synchronously collect the space electric field signal caused by fault and magnetic field signal .

3. The method of claim 2, wherein the method further comprises: S2 specifically comprises: S21, using COMSOL software to construct a simulation model according to the actual parameters of the power transmission line in a proportional manner, wherein the actual parameters include the conductor type, the tower height, the conductor ground distance and the number of split conductors, and the material properties of air, conductor and tower are set; S22, enable COMSOL software static module simulation transmission line below the space electric field distribution, through the corresponding relationship between electric field intensity and line voltage to get the conversion coefficient of space electric field and line voltage ; enable COMSOL software current module simulation tower near the space magnetic field distribution, through the corresponding relationship between magnetic field intensity and line current to get the conversion coefficient of space magnetic field and line current ; S23、based on the conversion coefficient and The fault voltage traveling wave signal is calculated by traveling wave inversion and the current traveling wave signal The formula is: 。 4. The method of claim 3, wherein the method further comprises: S3 specifically comprises: S31, the voltage traveling wave signal obtained by inversion and the current traveling wave signal are respectively accessed to different channels of the same high-speed acquisition card, and the impedances of the two signal access paths are matched to realize multi-channel synchronous sampling. S32, using analog level trigger mode, preset trigger threshold, when the voltage traveling wave signal or current traveling wave signal the signal amplitude of the channel where the signal is located exceeds the threshold, trigger the synchronous start of all channels of the high-speed acquisition card to start acquisition. S33, access GPS timing module, high-speed acquisition card signal acquisition time to calibrate, voltage traveling wave signal and current traveling wave signal acquired at the same time reference; S34, suppressing noise of the input signal through the signal conditioning circuit built in the acquisition card, converting the analog signal into a digital signal through an A / D converter, and synchronously storing the digital signal into the storage unit of the acquisition card.

5. The method of claim 4, wherein the method further comprises: S4 specifically comprises: S41, the voltage traveling wave signals and current traveling wave signals synchronously collected are converted into voltage pulse sequence A and current pulse sequence B with time mark and phase information respectively through wave head detection algorithm, wherein the phase information is calculated through fast Fourier transform of the voltage traveling wave digital signal and the current traveling wave digital signal, and the formula is: ； wherein is a time domain sequence of a traveling wave digital signal, denotes a fast Fourier transform operation, denotes taking the argument of a complex number, is a phase value; S42, from the first pulse of the voltage pulse sequence A, extract the time mark of the pulse , check if there is a pulse signal in the current pulse sequence B at the time; when there is and the phases are in the same direction, mark the pulse as the first voltage traveling wave, record the wave head time , and record the pulse as the pulse of sequence A, wherein ; when there is no pulse signal or the phases of the two pulses are in different directions, determine that the pulse is an interference signal, continue to check the second, third, to the pulse of sequence A, wherein is the total number of initial pulses of sequence A, until the first voltage traveling wave is identified; when all pulses are traversed and no pulse signal is identified, determine that the current collected signal is an invalid interference signal, terminate the detection process; S43, taking the pulse corresponding to the first voltage traveling wave as the... The pulse is used to sequentially check the first pulse of sequence A. 1 pulse, of which Given the total number of pulses in voltage pulse sequence A, extract the first pulse. Time markers for each pulse ,and Check sequence B in Check if a pulse signal exists at any given time; if a pulse signal exists and the two pulses are out of phase, mark the pulse as a reflected voltage traveling wave and record its wavefront time. When there is no pulse signal or the two pulses are out of phase, the pulse is determined to be an interference signal, and the next pulse is checked. S44, after the traversal, output all the marked first voltage traveling wave wave front time , reflected voltage traveling wave wave front time , complete fault traveling wave detection.

6. The method of claim 3, wherein the method further comprises: The boundary condition of the COMSOL simulation model in S21 is set as follows: the power transmission line conductor is applied with a rated operating voltage, the tower and the ground are set as grounding potential, and the air domain boundary is set as a far-field condition to simulate an infinite space environment.

7. The method of claim 4, wherein the method further comprises: The signal conditioning circuit in S34, the resistance-capacitance parameter of the low-pass filter circuit is according to the cut-off frequency Design, operational amplifier circuit using high common-mode rejection ratio operational amplifier, ensure the noise suppression effect and signal linear amplification.

8. The method of claim 4, wherein the method further comprises: The bit number of the A / D converter built in the high-speed acquisition card in S34 is 16 bits or more, so as to ensure the accuracy and speed of the conversion of the weak forward wave analog signal into a digital signal.

9. The method of claim 5, wherein the method further comprises: The wave head detection algorithm in S41 is specifically: performing sliding window processing on the traveling wave digital signal to calculate the signal amplitude difference of adjacent windows , and the formula is: ； When the signal amplitude is determined the time is the wave head position, and the signal at this time is extracted as a pulse of the pulse sequence, wherein is the standard deviation of the signal amplitude during normal operation.

10. The method of claim 3, wherein the method further comprises: The conversion coefficient is calculated in S22 The average value of the electric field intensity at the deployment position of the electric field sensor is taken , and the ratio of the applied voltage to the line is ; the conversion coefficient is calculated The average value of the magnetic field intensity at the deployment position of the magnetic field sensor is taken , and the ratio of the current passing through the line to the line is , wherein and are calculated by the area integration function of the COMSOL simulation result, and the integration area is the actual deployment space of the sensor.

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