Power transmission line fault traveling wave monitoring and distance measuring method

What is AI technical title?
AI technical title is built by Patsnap AI team. It summarizes the technical point description of the patent document.
By installing detection devices on transmission lines and processing signals using wavelet filtering and Hilbert-Huang transform, combined with theoretical and actual wave velocity calculations, the problem of inaccurate fault location determination in existing technologies has been solved, achieving high-precision fault location and improving maintenance efficiency.

CN120928104APending Publication Date: 2025-11-11ZIBO ZHIXING ELECTRONIC TECHNOLOGY CO LTD

View PDF 0 Cites 0 Cited by

Patent Information

Application Number: CN202510922453.8
Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner
Filing Date: 2025-07-04
Publication Date: 2025-11-11

AI Technical Summary

Technical Problem

Existing fault detection methods for power transmission lines cannot accurately determine the location of faults, resulting in untimely repairs and low maintenance efficiency.

Method used

Traveling wave signal acquisition and processing technology is adopted. By installing detection devices at both ends and the midpoint of the transmission line, wavelet filtering and Hilbert-Huang transform are used to process the signal. Combined with theoretical and actual wave velocity calculations, the fault location calculation is optimized, and thresholds and feedback analysis are set to improve accuracy.

Benefits of technology

It achieves high-precision location of fault points in transmission lines, improves inspection and maintenance efficiency, reduces large errors caused by faulty detection devices, and adapts to parameter changes during long-term use of transmission lines.

✦ Generated by Eureka AI based on patent content.

Smart Images

Figure CN120928104A_ABST

Patent Text Reader

Abstract

The invention belongs to the technical field of power transmission line fault detection, and discloses a power transmission line fault traveling wave monitoring and distance measuring method, which comprises the following steps: S1, traveling wave signal acquisition, S2, traveling wave signal processing, S3, traveling wave velocity approval and selection, determining the traveling wave velocity through calculation and comparison of multiple groups of data, S4, calculating the position of a fault point, and S5, determining the position of the fault point. According to the technical scheme, multiple operations are carried out through collection of multiple sets of signals, the calculation results of the multiple sets of signals are matched with the theoretical calculation result to carry out comparative analysis to determine the calculation error, then the calculation error of the fault point is reduced, and the calculation accuracy of the fault point is improved. The position of a fault point can be determined more accurately, and the overhaul and maintenance efficiency is improved; instrument faults can be judged according to the comparison effect, fault point position calculation is conducted through a limited calculation formula, influences of other parameters are avoided, and the calculation precision is further improved.

Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] This invention relates to the field of power transmission line fault detection technology, and in particular to a method for monitoring and ranging traveling waves in power transmission line faults. Background Technology

[0002] Transmission line fault detection methods are used to detect faults in transmission lines and determine their type and location. Specifically, these methods identify fault conditions by monitoring changes in parameters such as current, voltage, and power along the line and by utilizing the characteristics of fault signals. Commonly used fault detection methods include: current / voltage differential protection, which detects faults such as short circuits and grounding by comparing the current or voltage difference between the two ends of the line; frequency domain analysis, which detects frequency component changes caused by faults, such as harmonics and abrupt changes, by performing spectral analysis on the line current and voltage signals; waveform analysis, which detects waveform distortion and fluctuations caused by faults by analyzing changes in the line current and voltage waveforms; and artificial intelligence technology, which utilizes machine learning, deep learning, and other techniques to achieve automated fault detection and diagnosis by building fault models and analyzing data.

[0003] Currently, most transmission line fault detection methods rely on direct analysis and calculation of the detected signals, which makes it difficult to accurately determine the location of the fault. This results in untimely fault repair and low maintenance efficiency. Summary of the Invention

[0004] The present invention aims to provide a method for monitoring and ranging traveling waves of transmission line faults, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for monitoring and ranging traveling waves of transmission line faults includes the following steps: S1. Traveling wave signal acquisition: Install a detection device for detecting traveling wave signals at both ends of the transmission line. The two sets of detection devices are designated as G1 and G3 respectively. Install another detection device at the midpoint of G1 and G3, labeled as G2. Acquire the traveling wave signal through the detection device and transmit the traveling wave signal to the terminal processing equipment. S2. Traveling wave signal processing: After receiving the traveling wave signal collected by the detection device, the terminal processing equipment performs noise removal and extraction processing on the traveling wave signal. First, the noise and low-frequency interference in the signal are removed by the wavelet filtering algorithm to obtain the accurate fault traveling wave signal. Then, the noise-removed traveling wave signal is decomposed into multiple intrinsic mode function (IMF) components by the Hilbert-Huang transform (HHT). The instantaneous frequency and amplitude characteristics of each IMF component are analyzed to extract the initial wavefront characteristics of the fault traveling wave. The time when the wavefront arrives at the corresponding detection device is taken as the initial arrival time of the fault traveling wave to obtain the time when the fault point arrives at the detection device. The corresponding times are marked as t1, t2 and t3.

[0006] S3. Approval and selection of traveling wave velocity: First, calculate the theoretical wave velocity of the traveling wave in the corresponding transmission line according to the following calculation formula. Where L is the inductance per unit length, C is the capacitance per unit length, and V is the theoretical propagation speed of the traveling wave; The fault location is determined based on the values of t1, t2, and t3. Specifically, if t3 > t1, the fault is located between G1 and G2; otherwise, it is located between G2 and G3. The travel time of the traveling wave signal between the two sets of detection devices is obtained by subtracting the time it takes for the wavefront to reach the detection device at the farthest point from the fault point from the time it takes to reach the intermediate detection device. The distance between the two sets of detection devices is known, and by comparing the two, the actual traveling wave velocity Vs in the transmission line can be obtained. The design threshold is set so that when the difference between the actual moving wave speed and the theoretical moving wave speed is within the set threshold, the actual moving wave speed Vs is used as the calculation base. When the difference between the actual moving wave speed and the theoretical moving wave speed is greater than the set threshold, the calculation is performed. When the results of multiple calculations all show that they are greater than the set threshold, a fault signal is issued, and maintenance personnel of the corresponding line section are dispatched to replace the detection devices at three locations at the same time, install new detection devices, and re-acquire and calculate the signal. S4. Calculate the location of the fault point. Based on the wave velocity calculation baseline obtained in S3, calculate the location of the fault point using the following formula. Where x is the distance from the fault point to endpoint A. The time it takes for the fault traveling wave to reach the detection device at end A. V is the time it takes for the fault traveling wave to reach the detection device at end B, V is the traveling wave velocity, and J is the total length of the line. S5. Fault location verification: From the above formula, the distance from the fault point to point A is... in The time it takes for the fault traveling wave to reach the C-end detection device is, in the application, the time it takes for the fault point to reach the intermediate detection device. According to the above calculation formula, the accuracy of the calculation for x can be monitored. Specifically, based on the time data detected by the three sets of detection devices, two sets of x data can be obtained. When the difference between the two sets of x data is within the set threshold, the calculation structure can be adopted. When the difference between the two sets of x data is greater than the set threshold, the traveling wave signal acquisition and detection calculation are repeated to improve the accuracy of the fault point location calculation. S6. Data feedback update: Staff obtain the fault point and conduct on-site inspection and repair. During the repair, staff will determine the actual fault point. After the repair is completed, the actual fault point location is fed back to the terminal processing equipment. The terminal processing equipment optimizes the comparison threshold between the theoretical traveling wave velocity and the actual traveling wave velocity based on the actual fault point location to improve the subsequent fault point location accuracy.

[0007] Preferably, the detection device is connected to a GPS system, which is used to locate the detection device and synchronize its clock, thereby reducing data acquisition errors.

[0008] Preferably, the sampling frequency of the detection device is 10MHz. Preferably, in step S6, when the actual fault location and the calculated fault location are within the designed error range, there is no need to optimize the comparison threshold between the theoretical traveling wave velocity and the actual traveling wave velocity.

[0009] Preferably, in S3, when the actual moving wave speed is selected as the calculation technology, an auxiliary fault point location can be calculated simultaneously based on the theoretical moving wave speed. Subsequently, the actual fault point location reported by the staff is compared with the auxiliary fault point location and the calculated fault point location to determine whether the detection device has malfunctioned and to issue a maintenance signal.

[0010] Preferably, a display terminal is provided, and the terminal processing device outputs the fault point to the display terminal.

[0011] The beneficial effects of this technical solution compared to existing technologies are as follows: (1) This technical solution performs multiple calculations by acquiring multiple sets of signals, and compares and analyzes the calculation results of multiple sets of signals with the theoretical calculation results to determine the calculation error, thereby reducing the calculation error of the fault point, and can more accurately determine the location of the fault point, improving the efficiency of inspection and maintenance; the comparison effect can also judge the instrument fault, avoid the large error calculation result caused by the operation failure of the detection device, facilitate the staff to quickly inspect and maintain the detection device, and improve the stability of monitoring; at the same time, a feedback analysis step is set up so that the operating system can optimize and limit the data comparison value of error analysis according to the actual maintenance situation, so as to improve the accuracy of comparison analysis, and can update and determine the comparison standard in a timely manner in accordance with the parameter defense and environmental changes caused by the long-term use of the transmission line, which is convenient for long-term monitoring.

[0012] (2) Before calculating the signal data, this technical solution has undergone a variety of noise removal processes, which effectively improves the accuracy of the arrival time of the traveling wave, thereby improving the accuracy of subsequent calculations, thus realizing high-precision location of transmission line faults and improving the adaptability and reliability of the method; the use of a limited calculation formula to calculate the location of the fault point avoids the influence of other parameters, further improving the calculation accuracy and maintenance efficiency. Attached Figure Description

[0013] Figure 1 This is a flowchart provided for the present invention; Detailed Implementation The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: A method for monitoring and ranging traveling waves of transmission line faults includes the following steps: S1. Traveling wave signal acquisition: A detection device for detecting traveling wave signals is installed at each end of the transmission line, labeled G1 and G3 respectively. Another detection device, labeled G2, is installed at the midpoint between G1 and G3. The distances between G2 and G1, and between G2 and G3, are known. The traveling wave signal is acquired through the detection devices and transmitted to the terminal processing equipment. The detection devices are connected to a GPS system for positioning and clock synchronization, reducing acquisition errors. The sampling frequency of the detection devices is 10MHz.

[0014] S2. Traveling wave signal processing: After receiving the traveling wave signal collected by the detection device, the terminal processing equipment performs noise removal and extraction processing on the traveling wave signal. First, the noise and low-frequency interference in the signal are removed by the wavelet filtering algorithm to obtain the accurate fault traveling wave signal. Then, the noise-removed traveling wave signal is decomposed into multiple intrinsic mode function (IMF) components by the Hilbert-Huang transform (HHT). The instantaneous frequency and amplitude characteristics of each IMF component are analyzed to extract the initial wavefront characteristics of the fault traveling wave. The time when the wavefront arrives at the corresponding detection device is taken as the initial arrival time of the fault traveling wave to obtain the time when the fault point arrives at the detection device. The corresponding times are marked as t1, t2 and t3.

[0015] S3. Approval and selection of traveling wave velocity: First, calculate the theoretical wave velocity of the traveling wave in the corresponding transmission line according to the following calculation formula. Where L is the inductance per unit length, C is the capacitance per unit length, and V is the theoretical propagation speed of the traveling wave; The fault location is determined based on the values of t1, t2, and t3. Specifically, if t3 > t1, the fault is located between G1 and G2; otherwise, it is located between G2 and G3. The travel time of the traveling wave signal between the two sets of detection devices is obtained by subtracting the time it takes for the wavefront to reach the detection device at the farthest point from the fault point from the time it takes to reach the intermediate detection device. The distance between the two sets of detection devices is known, and by comparing the two, the actual traveling wave velocity Vs in the transmission line can be obtained. The design threshold is set so that when the difference between the actual moving wave speed and the theoretical moving wave speed is within the set threshold, the actual moving wave speed Vs is used as the calculation base. When the difference between the actual moving wave speed and the theoretical moving wave speed is greater than the set threshold, the calculation is performed. When the results of multiple calculations show that they are greater than the set threshold, a fault signal is issued, and the maintenance personnel of the corresponding line section are dispatched to replace the detection devices at three locations at the same time and install new detection devices to re-acquire signals and perform calculations, that is, return to step 1 and continue. Specifically, for example, when t3 > t1, the fault point is located between G1 and G2. At this time, the travel time Δt of the traveling wave between G2 and G3 can be obtained by subtracting t2 from t3. After the detection device is installed, we can know the distance between G2 and G3. The actual traveling wave speed Vs can be obtained by dividing the distance between G2 and G3 by Δt. S4. Calculate the location of the fault point. Based on the wave velocity calculation baseline obtained in S3, calculate the location of the fault point using the following formula. Where x is the distance from the fault point to endpoint A. The time it takes for the fault traveling wave to reach the detection device at end A. V is the time it takes for the fault traveling wave to reach the detection device at end B, V is the traveling wave velocity, and J is the total length of the line. Specifically, when the fault point is located between G1 and G2, the value of t3 is input into the formula above. Input the output of t1 into the formula above. This gives the distance from the fault point to G3; S5. Fault location verification: From the above formula, the distance from the fault point to point A is... in The time it takes for the fault traveling wave to reach the C-end detection device is, in the application, the time it takes for the fault point to reach the intermediate detection device. The above calculation formula can be used to monitor whether the calculation of x is accurate. Specifically, based on the time data detected by the three sets of detection devices, two sets of x data can be obtained. When the difference between the two sets of x data is within the set threshold, the calculation structure can be adopted. When the difference between the two sets of x data is greater than the set threshold, the traveling wave signal acquisition and detection calculation are repeated to improve the accuracy of the calculation of the fault location. Specifically, when the fault point is located between G1 and G2, the value of t1 is input into the formula above. Input the output of t2 into the formula above. This will give you the distance from a fault point to G3. Input the value of t1 into the formula above. Input the output of t3 into the formula above. The distance from another fault point to G3 can then be obtained. If the monitoring is correct, the values of the two distances mentioned above are the same. At this time, it can be determined that there is no calculation error and the accurate fixed point position is obtained. When the error between the two is within a reasonable range, that is, within the set threshold range, the error can be ignored. At this time, the calculation results of t1 and t2 are taken as the fault point position. Because at this time, t1 and t2 are both less than t3, it means that the travel distance of the traveling wave is less than the distance of the traveling wave to G3. The error may be greater if the traveling wave travels a long distance. Therefore, the result of the shorter distance is more accurate. S6. Data Feedback Update: Staff obtain the fault point and conduct on-site inspection and repair. During the repair, staff will determine the actual fault point. After the repair is completed, the actual fault point location is fed back to the terminal processing equipment. The terminal processing equipment optimizes the comparison threshold between the theoretical traveling wave velocity and the actual traveling wave velocity based on the actual fault point location to improve the subsequent fault point location accuracy. When the actual fault point location and the calculated fault point location are within the designed error range, there is no need to optimize the comparison threshold between the theoretical and actual traveling wave velocities. When the actual fault point location and the calculated fault point location are outside the designed error range, it proves that there is a problem with the selection of the calculation basis in step S3. Since this data has been compared and the difference is within the threshold, the value of the threshold needs to be adjusted so that the traveling wave velocity cannot be calculated further under this data. The signal needs to be collected again for calculation to improve the calculation accuracy. In addition, a display terminal is provided, and the terminal processing equipment outputs the fault point to the display terminal, so that staff can quickly learn about the fault situation.

[0016] In S3, when the actual moving wave speed is selected as the calculation technology, an auxiliary fault point location can be calculated simultaneously based on the theoretical moving wave speed. Subsequently, the actual fault point location reported by the staff is compared with the auxiliary fault point location and the calculated fault point location to determine whether the detection device has malfunctioned and to issue a maintenance signal. Specifically, when the distance between the actual fault location and the theoretical fault location is greater than the distance between the actual fault location and the calculated fault location, it proves that the calculated fault location is correct and the detection device is operating within the acceptable error range. However, when the distance between the actual fault location and the theoretical fault location is less than the distance between the actual fault location and the calculated fault location, it proves that there is a significant error in the calculated fault location. In this case, it indicates a problem with the detection device. The terminal processing equipment sends a maintenance signal, and the staff of the corresponding road section simultaneously replace the detection device. After replacement, the operating status of the detection device can be determined by the detection agency, so as to conduct a comprehensive and overall fault analysis of the monitoring system and improve its efficiency.

[0017] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for monitoring and ranging traveling waves of transmission line faults, characterized in that, Includes the following steps: S1. Traveling wave signal acquisition: Install a detection device for detecting traveling wave signals at both ends of the transmission line. The two sets of detection devices are designated as G1 and G3 respectively. Install another detection device at the midpoint of G1 and G3, labeled as G2. Acquire the traveling wave signal through the detection device and transmit the traveling wave signal to the terminal processing equipment. S2. Traveling wave signal processing: After receiving the traveling wave signal collected by the detection device, the terminal processing equipment performs noise removal and extraction processing on the traveling wave signal. First, the noise and low-frequency interference in the signal are removed by the wavelet filtering algorithm to obtain the accurate fault traveling wave signal. Then, the noise-removed traveling wave signal is decomposed into multiple intrinsic mode function (IMF) components by the Hilbert-Huang transform (HHT). The instantaneous frequency and amplitude characteristics of each IMF component are analyzed to extract the initial wavefront characteristics of the fault traveling wave. The time when the wavefront arrives at the corresponding detection device is taken as the initial arrival time of the fault traveling wave to obtain the time when the fault point arrives at the detection device. The corresponding times are marked as t1, t2 and t3. S3. Approval and selection of traveling wave velocity: First, calculate the theoretical wave velocity of the traveling wave in the corresponding transmission line according to the following calculation formula. Where L is the inductance per unit length, C is the capacitance per unit length, and V is the theoretical propagation speed of the traveling wave; The fault location is determined based on the values of t1, t2, and t3. Specifically, if t3 > t1, the fault is located between G1 and G2; otherwise, it is located between G2 and G3. The travel time of the traveling wave signal between the two sets of detection devices is obtained by subtracting the time it takes for the wavefront to reach the detection device at the farthest point from the fault point from the time it takes to reach the intermediate detection device. The distance between the two sets of detection devices is known, and by comparing the two, the actual traveling wave velocity Vs in the transmission line can be obtained. The design threshold is set so that when the difference between the actual moving wave speed and the theoretical moving wave speed is within the set threshold, the actual moving wave speed Vs is used as the calculation base. When the difference between the actual moving wave speed and the theoretical moving wave speed is greater than the set threshold, the calculation is performed. When the results of multiple calculations all show that they are greater than the set threshold, a fault signal is issued, and maintenance personnel of the corresponding line section are dispatched to replace the detection devices at three locations at the same time, install new detection devices, and re-acquire and calculate the signal. S4. Calculate the location of the fault point. Based on the wave velocity calculation baseline obtained in S3, calculate the location of the fault point using the following formula. Where x is the distance from the fault point to endpoint A. The time it takes for the fault traveling wave to reach the detection device at end A. V is the time it takes for the fault traveling wave to reach the detection device at end B, V is the traveling wave velocity, and J is the total length of the line. S5. Fault location verification: From the above formula, the distance from the fault point to point A is... in The time it takes for the fault traveling wave to reach the C-end detection device is, in the application, the time it takes for the fault point to reach the intermediate detection device. According to the above calculation formula, the accuracy of the calculation for x can be monitored. Specifically, based on the time data detected by the three sets of detection devices, two sets of x data can be obtained. When the difference between the two sets of x data is within the set threshold, the calculation structure can be adopted. When the difference between the two sets of x data is greater than the set threshold, the traveling wave signal acquisition and detection calculation are repeated to improve the accuracy of the fault point location calculation. S6. Data feedback update: Staff obtain the fault point and conduct on-site inspection and repair. During the repair, staff will determine the actual fault point. After the repair is completed, the actual fault point location is fed back to the terminal processing equipment. The terminal processing equipment optimizes the comparison threshold between the theoretical traveling wave velocity and the actual traveling wave velocity based on the actual fault point location to improve the subsequent fault point location accuracy.

2. The method for monitoring and ranging traveling waves of transmission line faults as described in claim 1, characterized in that, Connect the detection device to the GPS system, and use the GPS system to locate the detection device and synchronize the clock, thereby reducing data acquisition errors.

3. The method for monitoring and ranging traveling waves of transmission line faults as described in claim 1, characterized in that, The sampling frequency of the detection device is 10MHz.

4. The method for monitoring and ranging traveling waves of transmission line faults as described in claim 1, characterized in that, In step S6, when the actual fault location and the calculated fault location are within the designed error range, there is no need to optimize the comparison threshold between the theoretical traveling wave velocity and the actual traveling wave velocity.

5. The method for monitoring and ranging traveling waves of transmission line faults as described in claim 1, characterized in that, In S3, when the actual moving wave speed is selected as the calculation technology, an auxiliary fault point location can be calculated simultaneously based on the theoretical moving wave speed. Subsequently, the actual fault point location reported by the staff is compared with the auxiliary fault point location and the calculated fault point location to determine whether the detection device has malfunctioned and to issue a maintenance signal.

6. The method for monitoring and ranging traveling waves of transmission line faults as described in claim 1, characterized in that, A display terminal is provided, and the terminal processing equipment outputs the fault point to the display terminal.