An overhead cable fault detection method combining with traveling wave ranging

Abstract

This invention discloses an overhead cable fault detection method combining traveling wave ranging and artificial intelligence algorithms. This invention relates to the field of cable fault detection technology and solves the problem that the arrival time of the traveling wave selected at a single moment is prone to deviation, leading to ranging errors. This invention utilizes a cross-validation mechanism combining multiple time sets in the dual-end traveling wave ranging method to perform non-repeated selection and verification of the traveling wave signal time received by the monitoring node across all scenarios. Combined with the dual verification logic of "length difference judgment + reflected wave time matching," it effectively avoids the risk of misjudgment due to signal interference from selecting a single moment. In particular, by comparing the reflected wave amplitude with the main traveling wave signal and performing dynamic movement verification, it further filters out accurate fault locations, solving the positioning deviation problem caused by interference such as early arrival of reflected waves and signal superposition in traditional traveling wave ranging, significantly improving the accuracy and stability of fault location.

Description

Technical Field

[0001] This invention relates to the field of cable fault detection technology, specifically to a method for detecting faults in overhead cables that combines traveling wave ranging. Background Technology

[0002] In the field of power system operation and maintenance, overhead cables, as a key carrier of power transmission, are crucial for ensuring the safe and stable operation of the power grid through rapid and accurate fault detection. Traditional overhead cable fault detection relies heavily on traveling wave ranging technology, which calculates the fault location by detecting the time difference between the arrival times of the traveling wave signal generated at the fault point at both ends of the line. However, this method faces many challenges in practical applications: Firstly, the traveling wave is easily affected by factors such as line noise, reflected wave interference, and impedance discontinuities (such as towers and branch points) during propagation, resulting in the initial traveling wave and reflected wave signals being mixed. The arrival time of the traveling wave selected at a single moment is prone to deviation, thus causing ranging errors. Secondly, traditional methods rely heavily on manual experience to analyze waveform characteristics for fault type identification, making it difficult to quantitatively distinguish different fault types such as metallic short circuits and high-resistance grounding. Furthermore, they lack robustness in the face of complex interference signals, easily leading to misjudgments or missed judgments.

[0003] Meanwhile, with the expansion of power grid scale and the increasing complexity of line structures, the traditional traveling wave ranging method of "single-time combination + simple threshold judgment" can no longer meet the requirements of high-precision detection. Problems such as incorrect time selection due to signal interference and mismatch between fault location and reflected wave characteristics occur frequently, increasing the time cost of fault diagnosis and affecting the timeliness of power grid repair. Therefore, how to optimize the time verification logic of traveling wave signals and strengthen the feature correlation analysis between reflected waves and main traveling waves to achieve accurate fault location and efficient fault type identification has become a key issue in improving the fault detection capability of overhead cables. Based on the above background, this application proposes a fault detection method combining traveling wave ranging and multi-dimensional feature verification, aiming to solve the pain points of low positioning accuracy, weak anti-interference ability, and ambiguous fault type identification in traditional technologies. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an overhead cable fault detection method that combines traveling wave ranging, solving the problem that the arrival time of the traveling wave selected at a single moment is prone to deviation, thus causing ranging errors.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for detecting faults in overhead cables using traveling wave ranging, comprising the following steps: Step 1: Confirm the traveling wave signals associated with the monitoring nodes on both sides of the fault node, and simultaneously confirm the reception time. Based on the processing progress, confirm the location of the fault point and the main traveling wave signal associated with the corresponding monitoring node. The specific method is as follows: The two sets of traveling wave signals received by a single monitoring node are confirmed, and the two confirmed reception times are recorded as T1 and T2 respectively. Then, the two sets of traveling wave signals received by another monitoring node are confirmed, and the two confirmed reception times are recorded as Z1 and Z2. The length of the line between the two sets of monitoring nodes is confirmed and denoted as L: Select T1 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. Confirm the minimum time value between T1 and Z1, and designate the monitoring node associated with the minimum time value as the priority node and the other monitoring node as the follow-up node. Confirm the time difference between T1 and Z1, and use the formula: time difference × v = length difference, where v is a preset value. Based on the confirmed length difference, if the length difference ≥ L, then proceed with the subsequent processing. If the length difference < L, confirm the qualified point within the transmission line. The length from the qualified point to the priority node is Lx, and the length to the follow-up node is Lh. Lx and Lh satisfy: Lh - Lx = length difference. Based on the confirmed qualified point, confirm whether the remaining T2 and Z2 both satisfy: T2 = (Lh + L) ÷ v and T1 = (Lx + L) ÷ v. If they satisfy, it means that the time selection is accurate, and the confirmed qualified point is marked as the fault point. If they do not satisfy, then proceed with the subsequent processing. Select T2 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. According to the above processing procedure, identify whether the fault location can be confirmed. If it can, stop the processing process; if not, continue to confirm. Similarly, different times are selected, and the selection process is not repeated. The corresponding fault location is identified and confirmed. If it still cannot be confirmed, an error signal is generated and displayed directly. Based on the confirmed fault node, the priority node and subsequent node associated with the corresponding confirmation process are locked, and the associated time selected by the corresponding monitoring node is confirmed from the confirmation process. The traveling wave signal received at the corresponding associated time is taken as the main traveling wave signal.

[0006] Step 2: Based on the main traveling wave signal confirmed by the corresponding monitoring node, record the traveling wave signal associated at another time as the transmitted signal, and perform feature verification between the reflected signal and the main traveling wave signal to identify and confirm the fault signal for display. The specific method is as follows: Identify the priority node from the corresponding monitoring nodes, and confirm the main traveling wave signal and transmitted signal associated with the priority node. Place the reflected signal and the main traveling wave signal in the same spectrum diagram, aligning the amplitude points associated with corresponding times. Denote the amplitude associated with different times within the reflected signal as F. k The amplitude associated with the corresponding time within the main traveling wave signal is denoted as Z. k , using: Fk ÷Z k =P k Confirmation time feature P k And associate different time features P with different times. k Perform mean processing to confirm monitoring characteristics; The duration Ts of the main traveling wave signal is confirmed, and the movable duration KT is confirmed by using Ts×0.3=KT. The reflected signal is controlled to move left and right under the set time state, and the movement time is (KT÷2). The monitoring characteristics associated with each movement process are confirmed. Based on the preset range, which includes the short circuit range and the high resistance range, the range to which the corresponding monitoring feature belongs is confirmed, and the number of monitoring features G1 in the corresponding range is recorded. Then, the total number of several monitoring features G2 is confirmed. If (G1÷G2)≥50% and the range belongs to the short circuit range, a short circuit fault signal is directly generated. If the range belongs to the high resistance range, a high resistance fault signal is directly generated. If (G1÷G2)<50%, the subsequent processing process is executed. Step 3: For cases where no fault signal is identified, identify the peak signal segment from the main traveling wave signal, then compare the peak signal segment with the preset associated connection line. Based on the comparison result, confirm the fault signal and output it. The specific method is as follows: The peak point is locked from the confirmed main traveling wave signal, and the undetermined segment is identified from the waveform segments associated with the peak point. The undetermined segment before the peak point is in a continuous climbing state, and the undetermined segment after the peak point is in a continuous descending state. Identify the initial point of the previous set of undetermined segments and the end point of the next set of undetermined segments, connect the initial point, peak point and end point to confirm the connection to be analyzed; The confirmed connection to be analyzed is compared with the preset associated connection. The peak points of the connection to be analyzed and the peak points of the associated connection are overlapped. The two sets of feature points associated on the same vertical and horizontal line are confirmed, and the interval amplitude between the two sets of feature points is recorded. If there is only one feature point on the same vertical and horizontal line, the amplitude of the corresponding feature point is used as the confirmed interval amplitude. The average of the confirmed interval amplitudes is then processed to confirm the comparison features. The connection to be analyzed is compared with different preset associated connections in turn, and the associated comparison features are confirmed. The minimum value is selected from the different comparison features associated with different comparison processes. The associated connection related to the minimum value is recorded as the selected connection. The fault feature associated with the selected connection is recorded as the confirmed feature, and the corresponding fault signal is directly generated and displayed.

[0007] Preferably, the short-circuit range is 0%-40%, and the high-resistance range is 60%-100%.

[0008] This invention provides a method for detecting faults in overhead cables that combines traveling wave ranging. Compared with existing technologies, it has the following advantages: This invention employs a cross-validation mechanism using multiple time combinations in the dual-end traveling wave ranging method to perform non-repeating selection and verification of the traveling wave signal times (T1, T2 and Z1, Z2) received by the monitoring node across the entire scenario. Combined with a dual verification logic of "length difference determination + reflected wave time matching," it effectively avoids the risk of misjudgment due to signal interference that may occur with single-time selection. In particular, by comparing the reflected wave amplitude with the characteristics of the main traveling wave signal (such as time feature P), it further enhances the accuracy of the verification. k The mean value calculation and dynamic movement verification further screen out the accurate fault location, which solves the positioning deviation problem caused by interference such as early arrival of reflected waves and signal superposition in traditional traveling wave ranging, and significantly improves the accuracy and stability of fault location. By analyzing the spectral characteristics of the main traveling wave signal and the reflected wave signal, and matching the amplitude ratio (monitoring feature) with preset threshold ranges (short-circuit range, high-impedance range), combined with the comparison mechanism of the undetermined connection of the peak signal segment with the preset associated connection, this method achieves accurate differentiation of different fault types such as short-circuit faults (high reflection coefficient) and high-impedance faults (low reflection coefficient). This method fully utilizes the waveform fingerprint characteristics of the fault traveling wave, transforming abstract signal features into quantifiable judgment indicators, avoiding the subjectivity of traditional manual experience judgment, and providing an objective basis for fault cause analysis. To address the issue of incorrect timing selection caused by signal interference, a progressive timing combination verification process was designed. Through multiple rounds of non-repeating timing selection and verification, if the fault location still cannot be identified, an error signal is generated to ensure the rigor of the processing logic in complex interference environments (such as high-frequency noise and multiple reflection waves). At the same time, by analyzing the rising / falling trend of the peak signal segment and comparing it with the preset associated connections, the method can quickly locate abnormal features using a preset library of historical fault characteristics, further improving its adaptability and anti-interference capability in complex line environments (such as multi-branch and high-resistance grounding). Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] First Embodiment

[0012] Please see Figure 1 This application provides a fault detection method for overhead cables combined with traveling wave ranging, including the following steps: Step 1: Confirm the traveling wave signals associated with the monitoring nodes on both sides of the fault node and simultaneously confirm the reception time. Based on the processing progress, confirm the location of the fault point and the main traveling wave signal associated with the corresponding monitoring node. Specifically, when there is a fault in the line between the corresponding monitoring nodes, a fault traveling wave signal will be generated. This signal will propagate rapidly along the conductor to both ends. The double-ended traveling wave ranging method involves installing traveling wave ranging equipment at both ends of the line to receive the traveling wave signal and confirm the location of the fault associated with the corresponding line based on the reception time of the corresponding traveling wave signal. However, if there is interference in the main traveling wave signal during the reception process, the reflected signal will arrive prematurely, which will cause analysis errors. Therefore, in order to achieve a more accurate identification effect, the reception confirmation of the two sets of traveling wave signals received by the monitoring node is performed here to identify the signal characteristics of the corresponding traveling wave signal. The specific method for confirming the location of the fault point based on the processing progress is as follows: The two sets of traveling wave signals received by a single monitoring node are confirmed, and the two confirmed reception times are recorded as T1 and T2 respectively. Then, the two sets of traveling wave signals received by another monitoring node are confirmed, and the two confirmed reception times are recorded as Z1 and Z2. The length of the line between the two sets of monitoring nodes is confirmed and denoted as L: Select T1 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. Confirm the minimum time value between T1 and Z1, and designate the monitoring node associated with the minimum time value as the priority node (i.e., the node where the traveling wave signal arrives first). Designate the other monitoring node as the follow-up node. Confirm the time difference between T1 and Z1, and apply the formula: Time difference × v = Length difference, where v is a preset value, determined in advance by the operator based on experience, generally close to the speed of light for electromagnetic wave propagation. Based on the confirmed length difference, if the length difference... If the time difference is greater than or equal to L (indicating an error in time selection), then proceed with the subsequent processing steps. If the length difference is less than L, then a qualified point is confirmed within the transmission line. The length from the qualified point to the priority node is Lx, and the length to the subsequent node is Lh. Lx and Lh satisfy: Lh - Lx = length difference. Based on the confirmed qualified point, check whether the remaining T2 and Z2 both satisfy: T2 = (Lh + L) ÷ v and T1 = (Lx + L) ÷ v. If they satisfy, then the time selection is accurate, and the confirmed qualified point is marked as the fault point. If they do not satisfy, then proceed with the subsequent processing steps. Select T2 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. According to the above processing procedure, identify whether the fault location can be confirmed. If it can, stop the processing process; if not, continue to confirm. Similarly, different times are selected, and the selected processes are not repeated. The corresponding fault points are identified and confirmed. If they still cannot be confirmed, an error signal is generated directly (indicating that there is corresponding signal interference, which causes a large error in the actual processing process, so the corresponding fault point cannot be confirmed). In the subsequent processing process, T1, Z2 and T2, Z2 are selected as the first processing time and the second processing time in sequence to complete the corresponding processing process until the entire processing process ends. The method for confirming the main traveling wave signal associated with the corresponding monitoring node is as follows: Based on the confirmed fault node, the priority node and subsequent node associated with the corresponding confirmation process are locked, and the associated time selected by the corresponding monitoring node is confirmed from the confirmation process. The traveling wave signal received at the corresponding associated time is used as the main traveling wave signal to complete the confirmation process. Specifically, when the corresponding monitoring node is a priority node, its associated time is T1. Then, the traveling wave signal associated with the corresponding time T1 is locked. The locked traveling wave signal is the main traveling wave signal associated with the corresponding priority node. Similarly, the traveling wave signals associated with subsequent nodes also adopt the same confirmation method.

[0013] Step 2: Based on the main traveling wave signal confirmed by the corresponding monitoring node, record the traveling wave signal associated at another time as the transmitted signal, and perform feature verification between the reflected signal and the main traveling wave signal to identify and confirm the fault signal for display. Specifically, different reflection situations exist for different fault states. If the corresponding line fault node is a short circuit fault, the resulting reflection coefficient is relatively large. If the corresponding line fault node is a high impedance fault, the resulting reflection coefficient is relatively small. Therefore, the fault signal confirmation process can be carried out based on such characteristics. The specific methods for identifying and confirming fault signals are as follows: Identify the priority node from the corresponding monitoring nodes, and confirm the main traveling wave signal and transmitted signal associated with the priority node. Place the reflected signal and the main traveling wave signal in the same spectrum diagram, aligning the amplitude points associated with the corresponding times (in the spectrum diagram, the time point associated with the initial point of the corresponding signal is the 0-value point, and its time is the calibrated time). Denote the amplitude associated with different times in the reflected signal as F. k The amplitude associated with the corresponding time within the main traveling wave signal is denoted as Z. k , using: F k ÷Z k =Pk Confirmation time feature P k And associate different time features P with different times. k Perform mean processing to confirm monitoring characteristics; The duration Ts of the main traveling wave signal is confirmed, and the movable duration KT is confirmed by using Ts×0.3=KT. The reflected signal is controlled to move left and right under the set time state, and the movement time is (KT÷2). The monitoring characteristics associated with each movement process are confirmed. Based on the preset range, which includes short circuit range (0%-40%) and high resistance range (60%-100%), the range to which the corresponding monitoring feature belongs is confirmed, and the number of monitoring features G1 in the corresponding range is recorded. Then, the total number of several monitoring features G2 is confirmed. If (G1÷G2)≥50% and the range belongs to the short circuit range, a short circuit fault signal is directly generated. If the range belongs to the high resistance range, a high resistance fault signal is directly generated. If (G1÷G2)<50%, the subsequent processing process is executed. Specifically, in the confirmation process, the confirmed monitoring features generally include many groups. In order to achieve a more accurate identification effect, it is necessary to confirm the range to which the corresponding monitoring feature belongs. Based on the confirmed range, the specific abnormal state of the monitoring feature is identified. Thus, based on the identified abnormal state, the relevant judgments of short circuit and high resistance can be made, and the signal can be displayed. This can not only effectively identify the fault point, but also simultaneously identify the corresponding fault cause, which is convenient for relevant maintenance personnel to carry out timely inspection and maintenance. Step 3: For cases where no fault signal is identified, identify the peak signal segment from the main traveling wave signal, then compare the peak signal segment with the preset associated connection line. Based on the comparison result, confirm the fault signal and output it. The specific method for confirming the fault signal is as follows: The peak point is located from the confirmed main traveling wave signal, and the undetermined segment is identified from the waveform segments associated with the peak point. The undetermined segment before the peak point is in a continuous climbing state, and the undetermined segment after the peak point is in a continuous descending state (that is, a climbing segment and a descending segment, and the intersection point associated with the climbing segment and the descending segment is the corresponding peak point). Identify the initial point of the previous set of undetermined segments and the end point of the next set of undetermined segments, connect the initial point, peak point and end point to confirm the connection to be analyzed; The confirmed connection to be analyzed is compared with the preset associated connection (different fault characteristics correspond to different associated connections). The peak points of the connection to be analyzed and the peak points of the associated connection are overlapped. The two sets of characteristic points associated on the same vertical and horizontal line are confirmed, and the interval amplitude between the two sets of characteristic points is recorded. If there is only one characteristic point on the same vertical and horizontal line, the amplitude of the corresponding characteristic point is used as the confirmed interval amplitude. The average of the confirmed interval amplitudes is then processed to confirm the comparison features. The connection to be analyzed is compared with different preset associated connections in turn, and the associated comparison features are confirmed. The minimum value is selected from the different comparison features associated with different comparison processes. The associated connection related to the minimum value is recorded as the selected connection. The fault feature associated with the selected connection is recorded as the confirmed feature. The corresponding fault signal is directly generated and displayed for external personnel to view. Specifically, in the corresponding confirmation process, different signal waves have different waveform characteristics, which can identify different connections to be analyzed. The confirmed connections to be analyzed are compared with the preset associated connections, which can quickly lock the associated abnormal features and display the signals. In the historical processing process, different fault states have different peak characteristics. These characteristics can be preset by relevant operators in advance to ensure the accuracy of fault signal confirmation and to display the signals.

[0014] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0015] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. 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 be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for detecting faults in overhead cables combining traveling wave ranging, characterized in that, Includes the following steps: Step 1: Confirm the traveling wave signals associated with the monitoring nodes on both sides of the fault node, and simultaneously confirm the reception time. Based on the processing progress, confirm the location of the fault point and the main traveling wave signal associated with the corresponding monitoring node. The specific method is as follows: The two sets of traveling wave signals received by a single monitoring node are confirmed, and the two confirmed reception times are recorded as T1 and T2 respectively. Then, the two sets of traveling wave signals received by another monitoring node are confirmed, and the two confirmed reception times are recorded as Z1 and Z2. The length of the line between the two sets of monitoring nodes is confirmed and denoted as L: Select T1 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. Confirm the minimum time value between T1 and Z1, and designate the monitoring node associated with the minimum time value as the priority node and the other monitoring node as the follow-up node. Confirm the time difference between T1 and Z1, and use the formula: time difference × v = length difference, where v is a preset value. Based on the confirmed length difference, if the length difference ≥ L, then proceed with the subsequent processing. If the length difference < L, confirm the qualified point within the transmission line. The length from the qualified point to the priority node is Lx, and the length to the follow-up node is Lh. Lx and Lh satisfy: Lh - Lx = length difference. Based on the confirmed qualified point, confirm whether the remaining T2 and Z2 both satisfy: T2 = (Lh + L) ÷ v and T1 = (Lx + L) ÷ v. If they satisfy, it means that the time selection is accurate, and the confirmed qualified point is marked as the fault point. If they do not satisfy, then proceed with the subsequent processing. Select T2 from T1 and T2 as the first processing time, and select Z1 from Z1 and Z2 as the second processing time. According to the above processing procedure, identify whether the fault location can be confirmed. If it can, stop the processing process; if not, continue to confirm. Similarly, different times are selected, and the selection process is not repeated. The corresponding fault location is identified and confirmed. If it still cannot be confirmed, an error signal is generated and displayed directly. Step 2: Based on the main traveling wave signal confirmed by the corresponding monitoring node, record the traveling wave signal associated at another time as the transmitted signal, and perform feature verification between the reflected signal and the main traveling wave signal to identify and confirm the fault signal for display. Step 3: If the fault signal is not identified, identify the peak signal segment from the main traveling wave signal, then compare the peak signal segment with the preset associated connection line, and confirm the fault signal based on the comparison result and output it.

2. The overhead cable fault detection method combining traveling wave ranging according to claim 1, characterized in that, In step one, the method for confirming the main traveling wave signal associated with the monitoring node is as follows: Based on the confirmed fault node, the priority node and subsequent node associated with the corresponding confirmation process are locked, and the associated time selected by the corresponding monitoring node is confirmed from the confirmation process. The traveling wave signal received at the corresponding associated time is taken as the main traveling wave signal.

3. The overhead cable fault detection method combining traveling wave ranging according to claim 1, characterized in that, In step two, the specific method for identifying and confirming the fault signal is as follows: Confirm the priority node from the corresponding monitoring node, and confirm the main traveling wave signal and the emission signal associated with the priority node, and place the reflected signal and the main traveling wave signal in the same frequency spectrum diagram, align the amplitude points associated with the corresponding time, and record the amplitudes associated with different times in the reflected signal as F k Record the amplitudes associated with the corresponding time in the main traveling wave signal as Z k , use: F k ÷Z k =P k Confirm the time feature P k , and average process the different time features P k associated with different times to confirm the monitoring feature; The duration Ts of the main traveling wave signal is confirmed, and the movable duration KT is confirmed by using Ts×0.3=KT. The reflected signal is controlled to move left and right under the set time state, and the movement time is (KT÷2). The monitoring characteristics associated with each movement process are confirmed. Based on the preset range, which includes the short circuit range and the high resistance range, the range to which the corresponding monitoring feature belongs is confirmed, and the number of monitoring features G1 in the corresponding range is recorded. Then, the total number of several monitoring features G2 is confirmed. If (G1÷G2)≥50% and the range belongs to the short circuit range, a short circuit fault signal is directly generated. If the range belongs to the high resistance range, a high resistance fault signal is directly generated.

4. The overhead cable fault detection method combining traveling wave ranging according to claim 3, characterized in that, The short-circuit range is 0%-40%, and the high-resistance range is 60%-100%.

5. The overhead cable fault detection method combining traveling wave ranging according to claim 3, characterized in that, If (G1÷G2) < 50%, then proceed with the subsequent processing steps.

6. The overhead cable fault detection method combining traveling wave ranging according to claim 1, characterized in that, In step three, the specific method for confirming the fault signal is as follows: The peak point is locked from the confirmed main traveling wave signal, and the undetermined segment is identified from the waveform segments associated with the peak point. The undetermined segment before the peak point is in a continuous climbing state, and the undetermined segment after the peak point is in a continuous descending state. Identify the initial point of the previous set of undetermined segments and the end point of the next set of undetermined segments, connect the initial point, peak point and end point to confirm the connection to be analyzed; The confirmed connection to be analyzed is compared with the preset associated connection. The peak points of the connection to be analyzed and the peak points of the associated connection are overlapped. The two sets of feature points associated on the same vertical and horizontal line are confirmed, and the interval amplitude between the two sets of feature points is recorded. If there is only one feature point on the same vertical and horizontal line, the amplitude of the corresponding feature point is used as the confirmed interval amplitude. The average of the confirmed interval amplitudes is then processed to confirm the comparison features. The connection to be analyzed is compared with different preset associated connections in turn, and the associated comparison features are confirmed. The minimum value is selected from the different comparison features associated with different comparison processes. The associated connection related to the minimum value is recorded as the selected connection. The fault feature associated with the selected connection is recorded as the confirmed feature, and the corresponding fault signal is directly generated and displayed.

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