Double-ended non-synchronous traveling wave fault location method based on section constraint and application thereof
By installing traveling wave detection points on the transmission line and processing them in sections, and using section constraints to determine the fault section, the problems of high time synchronization accuracy and high hardware cost in traditional methods are solved, and efficient and low-cost fault location is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-23
AI Technical Summary
Traditional single-ended and double-ended traveling wave fault ranging methods suffer from problems such as significant impact on time synchronization accuracy, high hardware costs, and poor reliability of ranging results.
A dual-end asynchronous traveling wave fault location method based on section constraints is adopted. By installing traveling wave detection points at the beginning and end of the line, the line is divided into two sections. The length of the fault section is determined by using the time difference between the initial traveling wave and the characteristic wavefront, combined with the section constraint conditions, thus avoiding the influence of the reflected wave from the opposite end bus.
It enables accurate determination of the fault section length without the need for time synchronization, reduces hardware costs, simplifies operation, and improves the reliability and accuracy of ranging.
Smart Images
Figure CN122260031A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of transmission line fault location technology, and in particular to a method for locating double-ended asynchronous traveling wave faults based on section constraints and its application. Background Technology
[0002] Transmission lines are crucial facilities connecting the power generation end and the user side of a power system. Ensuring the reliable operation of the power system requires a robust power grid. However, because transmission lines are typically erected in areas with harsh geographical environments, they are susceptible to transient or permanent faults due to various factors. Researching rapid fault location methods for transmission lines is of great significance for shortening power outage time and improving the safety level of the power grid.
[0003] Traditional fault location methods based on the traveling wave method include the single-end method and the double-end method. The single-end method installs only one fault traveling wave detection device at one end of the line and calculates the location of the fault point by recording the time difference between the initial traveling wave and the first reflected wave at the fault point. The double-end method requires fault traveling wave detection devices to be installed at both ends of the line and uses the time difference of the initial traveling wave of the fault to arrive at both ends of the line to locate the fault point. Therefore, the detection points at both ends of the line need to be synchronized with high precision.
[0004] However, both methods have their limitations: the single-end method has difficulty determining whether the reflected traveling wave comes from the fault point or the opposite bus, which can affect the reliability of the ranging results in practical applications; the double-end method requires an additional fault ranging device, which has a high hardware cost, and the ranging accuracy is easily affected by fluctuations in time synchronization accuracy.
[0005] In view of this, this application proposes a new fault location method that aims to be unaffected by time synchronization accuracy and can accurately reflect the sources of each reflected traveling wave. Summary of the Invention
[0006] The main objective of this application is to provide a segment-constrained dual-end asynchronous traveling wave fault location method, which aims to solve the problem of how to achieve fault location that is not affected by time synchronization accuracy and can accurately reflect the sources of each reflected traveling wave.
[0007] To achieve the above objectives, this application provides a dual-end asynchronous traveling wave fault location method based on segment constraints, applicable to transmission lines with traveling wave detection points installed at both the beginning and end of the line, wherein the traveling wave detection points divide the transmission line into sections of length [missing information]. , The method comprises the following steps: (The two segments are defined as follows) S10, collect the arrival times of the initial traveling wave at the traveling wave detection points at the beginning and end of the line, respectively. , The subsequent characteristic wavefront arrival time series includes the time of the first reflected wave from the fault point at the traveling wave detection point at the beginning of the line. Time of reflected waves in the healthy sections of traveling wave detection points along the line and the arrival time of the first reflected wave at the fault point ; S20, determine the time of the reflected wave in the healthy section. Arrival time of the initial traveling wave of the fault at the end of the line The time difference between them is used to determine the target fault section. Section or Section; S30, determine the time of the reflected wave in the healthy section. Does the target fault section meet the corresponding section constraint conditions, wherein the section constraint conditions are determined by the arrival time of the initial traveling wave of the fault at the beginning of the line? The moment of the first reflected wave at the fault point And the reflection times of healthy sections along the line. and the arrival time of the first reflected wave at the fault point And the segment length of the target faulty section; S40, if satisfied, based on the segment length and the arrival time of the first reflected wave at the fault point... and the reflection time of the healthy section Determine the distance to the fault.
[0008] Optionally, in step S20, the step of determining the target fault section based on the time difference includes: S21, Determine whether the time difference satisfies the segment identification formula:
[0009] In the formula, For segment length, The propagation speed of a traveling wave of electric current. To match tolerance; S22, if satisfied, then the target fault section is determined to be... Section; S23, otherwise, determine the target fault section as... Section.
[0010] Optionally, the segment constraints include Section constraints and Section constraints, where: When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints; When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints.
[0011] Optionally, the The expression for the section constraint condition is:
[0012] The The expression for the section constraint condition is:
[0013] In the formula, The moment of the first reflected wave at the fault point Arrival time of the initial traveling wave of the fault The time difference between them The arrival time of the first reflected wave at the fault point along the line. and the reflection time of the healthy section The time difference between them; This refers to the matching tolerance for segment constraints.
[0014] Optionally, S40 includes: S41, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is:
[0015] S42, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is:
[0016] In the formula, The propagation speed of a traveling wave of electric current. x This is the distance from the fault point to the beginning of the line.
[0017] Optionally, before step S10, the following steps are also included: Collect current traveling wave data at traveling wave detection points installed at the beginning and end of the line; Wavelet coefficients and corresponding times of wavelet modulus maxima in current traveling wave data are extracted using wavelet transform.
[0018] In addition, to achieve the above objectives, this application also provides an application of the dual-end asynchronous traveling wave fault location method based on segment constraints as described in any of the preceding claims in fault location.
[0019] This application has at least the following beneficial effects: 1. Based on the traditional single-end traveling wave ranging device, an additional traveling wave measuring point along the line is added. The time difference between the first traveling wave of the fault observed at the beginning and the reflected wave at the fault point, and the time difference between the reflected wave of the opposite bus observed at the measuring point along the line and the first reflected wave at the fault point, constitute the constraint conditions. The two time differences can uniquely determine the length of the healthy section or the fault section. By being constrained by this section, the influence of the reflected wave of the opposite bus and the adjacent short-circuit wave process in the traditional single-end ranging can be avoided. 2. The fault section can be identified and its length determined by the time difference between the incident wave and the reflected wave from the opposite bus at the measurement point along the line. Furthermore, the traveling wave acquisition devices at both ends do not require clock synchronization, resulting in lower design costs and simpler operation. Attached Figure Description
[0020] Figure 1 This is a diagram of the power transmission line architecture involved in the embodiments of this application; Figure 2 This is a flowchart illustrating the dual-end asynchronous traveling wave fault location method based on segment constraints involved in the embodiments of this application; Figure 3 This is a schematic diagram showing the relationship between different moments in the transmission line involved in the embodiments of this application; Figure 4 This is a flowchart illustrating another embodiment of the dual-end asynchronous traveling wave fault location method based on segment constraints. The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0021] To better understand the above technical solutions, exemplary embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.
[0022] First Embodiment This embodiment provides a method for locating dual-end asynchronous traveling wave faults based on segment constraints. The method involves installing traveling wave detection points at both the beginning and end of the transmission line. These traveling wave detection points divide the transmission line into sections of length [length missing]. , The two sections. (Refer to...) Figure 1 Taking the 220kV transmission line shown as an example, a simulation model is built. A traveling wave detection device TA1 is installed at the M end, which is the beginning of the line. TA2 is installed at a line measurement point a certain distance along the beginning of the line. The distance between TA1 and TA2 is [length missing]. The section is called The distance between section TA2 and the N terminal (which is the end of the line) is a length of [length missing]. The section is called Section.
[0023] Based on this transmission line architecture, and referring to Figure 2 The method includes the following steps: S10, collect the arrival times of the initial traveling wave at the traveling wave detection points at the beginning and end of the line, respectively. , The subsequent characteristic wavefront arrival time series includes the time of the first reflected wave from the fault point at the traveling wave detection point at the beginning of the line. Time of reflected waves in the healthy sections of traveling wave detection points along the line and the arrival time of the first reflected wave at the fault point ; In this embodiment, the traveling current wave is monitored at traveling wave detection points installed at the beginning and end of the line. Wavelet transform is used to extract the wavelet coefficients and corresponding times of the wavelet modulus maxima of the current signal, and the installation positions of the measurement points along the line are obtained. , Based on the traveling wave data, fault line selection, phase selection and wavehead calibration are performed, and the arrival time series of the initial traveling wave and subsequent characteristic waveheads of the fault are collected at the beginning and along the measuring points.
[0024] By deploying traveling wave monitoring points along the ends of the line, the line can be divided into sections using these monitoring points. , The two sections are defined as follows: the section in which the fault occurs is the faulty section, and the other section is the healthy section.
[0025] In this embodiment, the subsequent characteristic wavefront arrival time series represents the arrival times of each traveling wave front at the two measuring points within a finite time after the initial traveling wave is received at the detection point. The characteristic time used for segment identification and fault location in the time series is the moment of the first reflected wave from the fault point at the first measuring point. Time of reflection of sound sections at measuring points along the route and the arrival time of the first reflected wave at the fault point .
[0026] To facilitate understanding of the specific location at each moment, refer to Figure 3 The fault F shown is in A schematic diagram of the wavefront timing in the section, assuming fault F is in Section, , These are the arrival times of the initial traveling wave at the traveling wave detection point TA1 at the beginning of the line, and the time of the first reflected wave from the fault point at the traveling wave detection point TA1, respectively. These are the arrival times of the reflected waves from the healthy section of the traveling wave detection point TA2 along the line, and the arrival times of the first reflected waves from the fault point.
[0027] Additionally, refer to Figure 4 The fault F shown is in A schematic diagram of the wavefront timing in the section, assuming fault F is in Section, then The positions are shown in the figure.
[0028] S20, determine the time of the reflected wave in the healthy section. The time of the first reflected wave at the fault point The time difference between them is used to determine the target fault section. Section or Section; After completing the time acquisition in step S10, the initial traveling wave arrival times at the measuring points along the line are... and healthy section reflection time The difference can uniquely reflect the length of the healthy segment.
[0029] Further and optionally, the target fault segment is determined based on the time difference. Section or The sections specifically include: S21, Determine whether the time difference satisfies the segment identification formula:
[0030] In the formula, For segment length, The propagation speed of a traveling wave of electric current. To match tolerance; S22, if satisfied, then the target fault section is determined to be... Section; S23, otherwise, determine the faulty section as... Section.
[0031] Matching tolerance is an empirical value set to account for factors such as traveling wave velocity attenuation in the circuit and calculation errors. In some optional implementations, The value is 1.5km.
[0032] S30, determine the time of the reflected wave in the healthy section. Does the target fault section meet the corresponding section constraint conditions, wherein the section constraint conditions are determined by the arrival time of the initial traveling wave of the fault at the beginning of the line? The moment of the first reflected wave at the fault point And the reflection times of healthy sections along the line. and the arrival time of the first reflected wave at the fault point And the segment length of the target faulty section; After identifying the target faulty section, verify the reflection time of the selected healthy section. Does the target fault segment meet the segment constraint conditions?
[0033] Further and optionally, the segment constraints include Section constraints and Section constraints, where: When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints; When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints.
[0034] Further and optionally, the The expression for the section constraint condition is:
[0035] The The expression for the section constraint condition is:
[0036] In the formula, The moment of the first reflected wave at the fault point Arrival time of the initial traveling wave of the fault The time difference between them The arrival time of the first reflected wave at the fault point along the line. and the reflection time of the healthy section The time difference between them; This refers to the matching tolerance for segment constraints.
[0037] The matching tolerance of the section constraint is an empirical value that takes into account the attenuation characteristics of the reflected wave in a sound section. In some optional implementations, the matching tolerance of the section constraint is taken as 2km.
[0038] S40, if satisfied, based on the segment length and the arrival time of the first reflected wave at the fault point... and the reflection time of the healthy section Determine the distance to the fault.
[0039] If the condition is met, calculate the fault distance. Further and optionally, S41, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is:
[0040] S42, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is:
[0041] In the formula, The propagation speed of a traveling wave of electric current. x This is the distance from the fault point to the beginning of the line.
[0042] In the technical solution provided in this embodiment, based on the traditional single-end traveling wave ranging device, an additional traveling wave measuring point along the line is added. The time difference between the first traveling wave observed at the first end of the fault and the reflected wave at the fault point, and the time difference between the reflected wave from the opposite bus and the first reflected wave at the fault point observed at the measuring point along the line, constitute constraints. These two time differences uniquely determine the length of the healthy or faulty section. This section constraint avoids the influence of the reflected wave from the opposite bus and the adjacent short-circuit wave process in traditional single-end ranging. Based on the time difference between the incident wave of the faulty section and the reflected wave from the opposite bus at the measuring point along the line, the faulty section can be identified, and the lengths of healthy and faulty sections can be determined. Furthermore, the traveling wave acquisition devices at both ends do not require clock synchronization, resulting in lower design costs and simpler operation.
[0043] Second Embodiment Based on the first embodiment, in this embodiment, Figure 3 Taking the model shown as an example, the line is 150km long. A traveling wave detection device is installed at the M end, and measuring points along the line are installed 110km away from the M end. Both ends of the line are multi-outgoing busbars. A current recording device with a 1MHz sampling rate is used to collect fault traveling wave data at the beginning and end of the line. When the section A C-phase ground fault occurred at 60km above the ground, with a transition resistance of 120Ω and a fault angle of 40 degrees.
[0044] Reference Figure 4 The flowchart shown in this embodiment involves collecting the arrival time series of the initial traveling wave and subsequent characteristic wavefronts at the fault's head and along the measuring points, respectively, and extracting the... The values are 150, 551, and 752. Given 150, 417, 551, 752, and 818, the arrival times of the initial traveling wave at the head end TA1 can be obtained. Arrival time of the initial traveling wave at end TA2 along the line .
[0045] Using the difference in arrival times between the initial traveling wave of the fault and the first reflected wave of the healthy section at the measuring points along the line, the fault section identification formula is applied: Therefore, it can be identified To improve the section, the fault occurred The arrival time of reflected waves in the intact sections along the line. .
[0046] The fault occurred in section Above, through The section constraint formula above verifies whether the selected wavefront meets the conditions and determines... , , ,but The possible sets are 551 and 752. The possible sets are 551, 752, and 818. First, we select the first time in each set for verification: Does not meet the requirements. Select the second moment in the set , , , If the section constraints are satisfied, then the arrival time of the first reflected wave from the fault point along the line is... .
[0047] use The section fault location formula calculates the length of the fault point from the beginning of the line. The fault location was thus determined.
[0048] Third Embodiment Based on the first embodiment, in this embodiment, Figure 4 Taking the model shown as an example, the line is 150km long. A traveling wave detection device is installed at the M end, and measuring points along the line are installed 100km away from the M end. Both ends of the line are multi-outgoing busbars. A current recording device with a sampling rate of 1MHz is used to collect fault traveling wave data at the beginning and end of the line. When the section L A phase-to-ground short circuit occurred at 140km on the 2nd line, with a transition resistance of 200Ω and a fault angle of 30 degrees. Fault section identification and fault distance measurement were carried out.
[0049] Reference Figure 4 The flowchart shown illustrates the acquisition of the arrival time series of the initial traveling wave and subsequent characteristic wavefronts at the fault's head and along the measuring points, respectively, and the extraction of... The values are 150, 216, 284, and 1085. Given 150, 216, 818, 884, and 1085, the arrival times of the initial traveling wave at the head end TA1 can be obtained. Arrival time of the initial traveling wave at end TA2 along the line .
[0050] Using the difference in arrival times between the initial traveling wave of the fault and the first reflected wave of the healthy section at the measuring points along the line, the fault section identification formula is applied: The segment identification conditions are not met, so the wavefront at 216µs is not a healthy segment reflection wave. Further wavefronts will be selected for further evaluation. Therefore, the fault was identified as occurring in The arrival time of reflected waves in the intact sections along the line. .
[0051] The fault occurred in section Above, through The section constraint formula above verifies whether the selected wavefront meets the conditions and determines... , , ,but The possible sets are 216, 284, and 1085. The possible sets are 884 and 1085. We will first select the first time in each set for verification. , Clearly, the selected wavefront does not satisfy the segment constraint; continue selecting... The first moment and Verification at the second moment in the set, , Constraint formula: Requirements not met; continue selecting The second moment in the set and Verify the combination of the first time step in the set: , Constraint formula: The constraints are still not satisfied. Next, we will verify the second time step from the two sets: Constraint Formula The constraints are not met; continue selecting. The third moment in the set and The combination at the second time step in the set is used for verification. , Constraint formula If the constraints are met, then The time it takes for the first reflected wave from the fault point to reach the first measuring point. This refers to the time it takes for the first reflected wave from the fault point to reach the measuring points along the line.
[0052] use The section fault location formula calculates the length of the fault point from the beginning of the line. The fault location was successfully identified, and the ranging results were relatively accurate, with the error controlled within 300m.
[0053] Furthermore, in this embodiment, the line length and the installation position of the measuring points along the line are changed, and different fault types and fault locations are set to verify the feasibility of the proposed method. The ranging results are shown in Table 1, which verifies that the method can reliably complete the section identification and fault ranging under different fault types for different line lengths and measuring point installation positions.
[0054] Table 1. Simulation data of the proposed method for fault segment identification and ranging results.
[0055] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0056] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A method for locating double-ended asynchronous traveling wave faults based on segment constraints, characterized in that, This method is applied to transmission lines where traveling wave detection points are installed at both the beginning and end of the line, wherein the traveling wave detection points divide the transmission line into sections of length [missing information]. , The method comprises the following steps: (The two segments are defined as follows) S10, collect the arrival times of the initial traveling wave at the traveling wave detection points at the beginning and end of the line, respectively. , The subsequent characteristic wavefront arrival time series includes the time of the first reflected wave from the fault point at the traveling wave detection point at the beginning of the line. Time of reflected waves in the healthy sections of the traveling wave detection points along the line. and the arrival time of the first reflected wave at the fault point ; S20, determine the time of the reflected wave in the healthy section. Arrival time of the initial traveling wave of the fault at the end of the line The time difference between them is used to determine the target fault section. Section or Section; S30, determine the time of the reflected wave in the healthy section. Does the target fault section meet the corresponding section constraint conditions, wherein the section constraint conditions are determined by the arrival time of the initial traveling wave of the fault at the beginning of the line? The moment of the first reflected wave at the fault point And the reflection times of healthy sections along the line. and the arrival time of the first reflected wave at the fault point And the segment length of the target faulty segment constitutes the total length of the faulty segment. S40, if satisfied, based on the segment length and the arrival time of the first reflected wave at the fault point... and the reflection time of the healthy section Determine the distance to the fault.
2. The method for locating dual-ended asynchronous traveling wave faults based on segment constraints as described in claim 1, characterized in that, In step S20, the step of determining the target fault section based on the time difference includes: S21, Determine whether the time difference satisfies the segment identification formula: ； In the formula, For segment length, The propagation speed of a traveling wave of electric current. To match tolerance; S22, if satisfied, then the target fault section is determined to be... Section; S23, otherwise, determine the target fault section as... Section.
3. The method for locating dual-ended asynchronous traveling wave faults based on segment constraints as described in claim 1, characterized in that, The segment constraints include Section constraints and Section constraints, where: When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints; When the target fault section is When segmenting, determine whether the acquisition wavefront meets the requirements. Section constraints.
4. The method for locating double-ended asynchronous traveling wave faults based on segment constraints as described in claim 3, characterized in that, The The expression for the section constraint condition is: ； The The expression for the section constraint condition is: ； In the formula, The moment of the first reflected wave at the fault point Arrival time of the initial traveling wave of the fault The time difference between them The arrival time of the first reflected wave at the fault point along the line. and the reflection time of the healthy section The time difference between them; This refers to the matching tolerance for segment constraints.
5. The method for locating dual-ended asynchronous traveling wave faults based on segment constraints as described in claim 1, characterized in that, S40 includes: S41, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is: ； S42, when the target fault section is When in sections, according to The section fault location formula determines the fault distance, the aforementioned The formula for section fault location is: ； In the formula, The propagation speed of a traveling wave of electric current. x This is the distance from the fault point to the beginning of the line.
6. The method for locating dual-ended asynchronous traveling wave faults based on segment constraints as described in claim 1, characterized in that, Before step S10, the following are also included: Collect current traveling wave data at traveling wave detection points installed at the beginning and end of the line; Wavelet coefficients and corresponding times of wavelet modulus maxima in current traveling wave data are extracted using wavelet transform.
7. An application of the dual-end asynchronous traveling wave fault location method based on segment constraints as described in any one of claims 1 to 6 in fault location.