A power transmission line arc length calibration and fault dynamic positioning method based on real-time feedback of suspension angle

Abstract

This invention relates to a method for arc length calibration and dynamic fault location of transmission lines based on real-time feedback of suspension angle. The method includes: setting up multiple distributed monitoring nodes along the transmission line within each span; calculating the actual arc length of the conductor within each span; obtaining the equivalent path length of traveling wave propagation between adjacent distributed monitoring nodes; calculating the fault location using a two-end traveling wave location formula; outputting the tower segment number where the fault occurs and the distance to the nearest tower, and reporting this to the monitoring center. This invention significantly improves positioning accuracy, eliminates path errors caused by sag, achieves closed-loop adaptive system operation, and can cope with sudden weather changes and line condition changes during heavy load operation without manual intervention; assists maintenance personnel in determining the patrol range and improves on-site handling efficiency; and utilizes a dual-range Rogowski coil current sensor design to simultaneously handle both low-resistance short-circuit large signals and high-resistance grounding weak signals, expanding the system's fault detection applicability.

Description

Technical Field

[0001] This invention relates to the field of online monitoring technology for power system transmission lines, and in particular to a method for calibrating the arc length of transmission lines and dynamically locating faults based on real-time feedback of suspension angle. Background Technology

[0002] Transmission lines are the core backbone of the power system, and their safe and stable operation is directly related to the reliability of the power grid. When a transmission line fault occurs, it is necessary to quickly and accurately locate the fault point to shorten the power outage time and reduce losses. The traveling wave fault location method, due to its advantages such as being unaffected by system operating conditions and high location accuracy, has been widely used in high-voltage and ultra-high-voltage transmission lines. However, the traveling wave fault location method has the following significant drawbacks:

[0003] First, the traveling wave velocity is used as a fixed value, without considering the effect of temperature: existing traveling wave positioning devices typically fix the traveling wave velocity of overhead lines at approximately [value missing]. The effect of conductor temperature changes on the conductor's distributed inductance was ignored. In reality, increased conductor temperature causes conductor expansion, affecting the geometry between the conductor and the ground, which in turn changes the inductance per unit length, causing a drift of 0.01% to 0.05% in the traveling wave velocity. For a 200km long transmission line, this error can result in a positioning error of approximately 20 to 100m.

[0004] Second, the line length uses a horizontal span, neglecting conductor sag: traveling waves actually propagate along the conductor, and their propagation path is the actual arc length of the conductor, not the horizontal straight-line distance between towers. Conductor sag dynamically changes with conductor temperature, load current, and environmental meteorological conditions. Under standard operating conditions, sag can reach 1% to 2% of the span, and it can further increase under heavy loads or high temperatures. Ignoring the sag error in line length, for long-distance lines in mountainous terrain, the cumulative error can exceed 1km, seriously affecting positioning accuracy.

[0005] Third, existing methods all employ offline parameter correction or static compensation, failing to achieve closed-loop dynamic correction based on real-time sensor data. Existing distributed traveling wave positioning patents, such as CN2019104977329 and CN117214610A, only treat sag correction as an optional post-processing step, and rely on manually input or offline calculated sag parameters, which cannot reflect the real-time operating status of the line. Their accuracy remains insufficient in scenarios such as sudden weather changes and large load fluctuations.

[0006] Fourth, the traveling wave signal from a high-impedance grounding fault is extremely weak, making it difficult for traditional single-range sensors to simultaneously meet the high dynamic range requirements. The amplitude of the traveling wave current generated by a high-impedance grounding fault (transition resistance above 100Ω) is only 1 / 100 or even lower than that of a low-impedance short-circuit traveling wave, while traditional Rogowski coils cannot guarantee a high signal-to-noise ratio for weak signals while meeting the requirements of a large current range. Summary of the Invention

[0007] To address the positioning error caused by fixed wave velocity and neglect of conductor sag in existing technologies, the present invention aims to provide a transmission line arc length calibration and fault dynamic location method based on real-time feedback of suspension angle that significantly improves positioning accuracy, eliminates path errors caused by sag, and can cope with changes in line conditions during sudden weather changes and heavy load operation without manual intervention.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a method for arc length calibration and dynamic fault location of transmission lines based on real-time feedback of suspension angle, the method comprising the following sequential steps:

[0009] (1) Multiple distributed monitoring nodes are set up along the transmission line in each span. Each distributed monitoring node synchronously collects the conductor suspension angle, temperature, altitude and current traveling wave signal at its span. The distributed monitoring nodes include fault monitoring nodes and tilt angle and temperature monitoring nodes.

[0010] (2) Based on the conductor suspension angle and altitude collected at each span, and using the catenary model, calculate the actual arc length of the conductor within each span. ;

[0011] (3) The actual arc length of the conductor within each span. By summing the results, the equivalent path length of the traveling wave propagation between adjacent distributed monitoring nodes can be obtained. And based on the equivalent path length Calculate the equivalent propagation speed of a traveling wave. ;

[0012] (4) When any fault monitoring node detects a sudden change in the current traveling wave signal, extract the arrival time of the traveling wave of the fault monitoring node, select the nearest fault monitoring node at both ends of the fault interval, and use the equivalent propagation speed The location of the fault point is calculated using the two-ended traveling wave location formula based on the arrival time difference of the traveling wave. ;

[0013] (5) Locate the fault point The system compares the data with the tower coordinate database, i.e., the database of the monitoring center, outputs the tower segment number where the fault occurred and the distance to the nearest tower, and reports it to the monitoring center.

[0014] Step (1) specifically refers to: along Transmission lines according to Distributed monitoring nodes are arranged at intervals; the tilt and temperature monitoring nodes are distributed between two adjacent fault monitoring nodes and close to the suspension point of the conductor on the tower. The horizontal span between adjacent towers is provided by the tower coordinate database. The fault monitoring nodes, tilt and temperature monitoring nodes are all clamped on the conductor.

[0015] The fault monitoring node includes a dual-range Rogowski coil current sensor, a first tilt sensor, a first temperature sensor, a high-speed ADC, a first low-speed ADC, a second low-speed ADC, a first computing processing unit, a first communication module, and a BeiDou / GPS dual-mode timing module. The output of the dual-range Rogowski coil current sensor is connected to the input of the high-speed ADC, the first tilt sensor is connected to the input of the first low-speed ADC, the first temperature sensor is connected to the input of the second low-speed ADC, and the outputs of the high-speed ADC, the first low-speed ADC, and the second low-speed ADC are all connected to the input of the first computing processing unit. The first computing processing unit communicates bidirectionally with the first communication module and the BeiDou / GPS dual-mode timing module, respectively.

[0016] The tilt and temperature monitoring node includes a second tilt sensor, a second temperature sensor, a third low-speed ADC, a fourth low-speed ADC, a second computing processing unit, and a second communication module. The output of the second tilt sensor is connected to the input of the third low-speed ADC, the output of the second temperature sensor is connected to the input of the fourth low-speed ADC, and both the third and fourth low-speed ADCs are connected to the input of the second computing processing unit. The second computing processing unit communicates bidirectionally with the second communication module.

[0017] The conductor suspension angle is collected by an inclination sensor, the temperature is collected by a temperature sensor, and the current traveling wave signal is collected by a dual-range Rogowski coil current sensor. The altitude of each tower is stored in the database of the monitoring center.

[0018] Step (2) specifically refers to: knowing the adjacent towers horizontal gap Altitude of adjacent tower suspension points and The suspension angle of the line between two adjacent towers and ;in, For the left tower, For the right tower;

[0019] Calculate the elevation difference between the suspension points of adjacent towers :

[0020] ;

[0021] With the left tower The suspension point is the origin, and the horizontal direction to the right is... The positive direction of the axis is vertically upward. If the axis is in the positive direction, then the coordinates of the suspension point of the left tower are: The coordinates of the suspension point of the right tower are ;

[0022] The shape of the line is a catenary, and the model of a catenary is represented as follows:

[0023] ;

[0024] In the formula, These are the horizontal translation parameters; For scale parameters; These are the vertical translation parameters; The vertical coordinate on the catenary model. The x-coordinate on the catenary model. represent and The functional relationship;

[0025] The slope of any point on the catenary curve is:

[0026] ;

[0027] At the suspension point, we have:

[0028] ;

[0029] In the formula, The horizontal distance;

[0030] The height difference between the suspension points of the left and right towers for:

[0031] ;

[0032] In the formula, The x-coordinate is The vertical axis of time; The x-coordinate is The vertical axis of time;

[0033] Using the properties of hyperbolic functions, We can obtain:

[0034] ;

[0035] Then the infinitesimal element of arc length for:

[0036] ;

[0037] Therefore, the actual arc length of the conductor within each span for:

[0038] .

[0039] Step (3) specifically refers to:

[0040] Will Substituting into the slope expression, we get:

[0041] ;

[0042] In the formula, For scale parameters; and The suspension angle of the line between two adjacent towers;

[0043] The slope expression is:

[0044] ;

[0045] In the formula, The horizontal distance;

[0046] Calculate the elevation difference between the suspension points of adjacent towers :

[0047] ;

[0048] therefore:

[0049] ;

[0050] Will Substituting into the arc length expression, we get:

[0051] ;

[0052] The arc length expression is:

[0053] ;

[0054] The total arc length of the line is the equivalent path length. for:

[0055] ;

[0056] In the formula, This represents the number of segments representing the horizontal distance between two fault monitoring nodes;

[0057] Equivalent propagation speed for:

[0058] ;

[0059] In the formula, For adjacent towers Horizontal clearance; For the standard traveling wave propagation speed of overhead lines, take .

[0060] Step (4) specifically refers to: processing the acquired current traveling wave signal Perform phase-mode transformation to extract the linear mode traveling wave component; perform multi-resolution wavelet transform on the linear mode traveling wave component, detect the modulus maxima in the 3rd to 5th decomposition layers, and identify the first one exceeding the threshold. The time corresponding to the modulus maximum point is determined as the arrival time of the traveling wave. ;

[0061] The threshold for:

[0062] ;

[0063] in, For coefficients, ; This is the effective value of the line load current;

[0064] Let the nearest monitoring nodes at both ends of the fault section be and , The arrival time of the traveling wave is , The arrival time of the traveling wave is Then the distance from the fault point The path distance is the location of the fault. for:

[0065] ;

[0066] In the formula, For monitoring nodes and The distance between them;

[0067] Distance from Fault path distance for:

[0068] .

[0069] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: First, significantly improve positioning accuracy: through real-time sag-temperature feedback, the path error caused by sag is eliminated, and theoretically, the positioning error caused by sag can be reduced from the original hundreds of meters to less than 20 meters; Second, achieve closed-loop adaptive system: sag-tilt angle sensing data and traveling wave positioning algorithm are deeply integrated to form a "perception-computation-correction" closed-loop architecture, which can cope with sudden weather changes and line condition changes during heavy load operation without manual intervention; Third, provide uncertainty quantification: while outputting positioning results, a confidence interval is given to assist maintenance personnel in judging the patrol range and improve on-site handling efficiency; Fourth, wide dynamic range hardware acquisition: the dual-range Rogowski coil current sensor design takes into account both low-resistance short-circuit large signals and high-resistance grounding weak signals, expanding the system's fault detection applicability range. Attached Figure Description

[0070] Figure 1 This is a schematic diagram of the overall architecture of the present invention;

[0071] Figure 2 This is a block diagram of the fault monitoring node structure;

[0072] Figure 3 Here is a block diagram of the tilt angle and temperature monitoring node structure;

[0073] Figure 4 This is a flowchart of the method of the present invention;

[0074] Figure 5 This is a schematic diagram of the power transmission towers and suspended transmission lines. Detailed Implementation

[0075] like Figure 4 As shown, a method for arc length calibration and dynamic fault location of transmission lines based on real-time feedback of suspension angle is presented. The method includes the following steps in sequence:

[0076] (1) Multiple distributed monitoring nodes are set up along the transmission line in each span. Each distributed monitoring node synchronously collects the conductor suspension angle, temperature, altitude and current traveling wave signal at its span. The distributed monitoring nodes include fault monitoring nodes and tilt angle and temperature monitoring nodes.

[0077] (2) Based on the conductor suspension angle and altitude collected at each span, and using the catenary model, calculate the actual arc length of the conductor within each span. ;

[0078] (3) The actual arc length of the conductor within each span. By summing the results, the equivalent path length of the traveling wave propagation between adjacent distributed monitoring nodes can be obtained. And based on the equivalent path length Calculate the equivalent propagation speed of a traveling wave. ;

[0079] (4) When any fault monitoring node detects a sudden change in the current traveling wave signal, extract the arrival time of the traveling wave of the fault monitoring node, select the nearest fault monitoring node at both ends of the fault interval, and use the equivalent propagation speed The location of the fault point is calculated using the two-ended traveling wave location formula based on the arrival time difference of the traveling wave. ;

[0080] (5) Locate the fault point The system compares the data with the tower coordinate database, i.e., the database of the monitoring center, outputs the tower segment number where the fault occurred and the distance to the nearest tower, and reports it to the monitoring center.

[0081] like Figure 1 As shown, step (1) specifically refers to: along Transmission lines according to Distributed monitoring nodes are arranged at intervals; the tilt and temperature monitoring nodes are distributed between two adjacent fault monitoring nodes and close to the suspension point of the conductor on the tower. The horizontal span between adjacent towers is provided by the tower coordinate database. The fault monitoring nodes, tilt and temperature monitoring nodes are all clamped on the conductor.

[0082] like Figure 2 As shown, the fault monitoring node includes a dual-range Rogowski coil current sensor, a first tilt sensor, a first temperature sensor, a high-speed ADC, a first low-speed ADC, a second low-speed ADC, a first computing processing unit, a first communication module, and a BeiDou / GPS dual-mode timing module. The output terminal of the dual-range Rogowski coil current sensor is connected to the input terminal of the high-speed ADC, the first tilt sensor is connected to the input terminal of the first low-speed ADC, the first temperature sensor is connected to the input terminal of the second low-speed ADC, and the output terminals of the high-speed ADC, the first low-speed ADC, and the second low-speed ADC are all connected to the input terminal of the first computing processing unit. The first computing processing unit communicates bidirectionally with the first communication module and the BeiDou / GPS dual-mode timing module, respectively.

[0083] like Figure 3 As shown, the tilt and temperature monitoring node includes a second tilt sensor, a second temperature sensor, a third low-speed ADC, a fourth low-speed ADC, a second computing processing unit, and a second communication module; the output of the second tilt sensor is connected to the input of the third low-speed ADC, the output of the second temperature sensor is connected to the input of the fourth low-speed ADC, both the third and fourth low-speed ADCs are connected to the input of the second computing processing unit, and the second computing processing unit communicates bidirectionally with the second communication module.

[0084] The suspension angle of the conductor is acquired by an inclination sensor, the temperature is acquired by a temperature sensor, and the traveling wave signal of the current is acquired by a dual-range Rogowski coil current sensor. The altitude of each tower is stored in the database of the monitoring center. The Beidou / GPS timing module adopts an event-triggered timing strategy: during normal operation, local timing is maintained by a built-in constant-temperature crystal oscillator, and precise time synchronization is automatically completed only when a traveling wave trigger event occurs, extending the timing interval from continuous synchronization mode to event-driven mode, reducing system power consumption by no less than 60%. The first and second computing processing units both use ARM Cortex-A55 with a main frequency of 1.2GHz, supporting real-time wavelet transform processing. The dual-range Rogowski coil current sensor consists of a large-range coil and a small-range high-sensitivity coil connected in parallel: the large-range coil has a measurement range of 0-40kA and is used to capture traveling waves from lightning strikes and short-circuit faults; the small-range high-sensitivity coil has a measurement range of 0-200A and is used to detect weak traveling wave signals generated by high-resistance grounding faults.

[0085] When tilt sensor data of a monitoring node is missing or abnormal, the following degraded calculation strategy is adopted: the equivalent temperature is estimated by using historical meteorological data of the towers at both ends of the span, and the arc length of the missing span is estimated by linear interpolation by combining the tilt data of nearby normal nodes. The uncertainty contribution of the arc length data of the span is marked in the positioning results.

[0086] like Figure 5 As shown, step (2) specifically refers to: knowing the adjacent towers horizontal gap Altitude of adjacent tower suspension points and The suspension angle of the line between two adjacent towers and ;in, For the left tower, For the right tower;

[0087] Calculate the elevation difference between the suspension points of adjacent towers :

[0088] ;

[0089] With the left tower The suspension point is the origin, and the horizontal direction to the right is... The positive direction of the axis is vertically upward. If the axis is in the positive direction, then the coordinates of the suspension point of the left tower are: The coordinates of the suspension point of the right tower are ;

[0090] The shape of the line is a catenary, and the model of a catenary is represented as follows:

[0091] ;

[0092] In the formula, These are the horizontal translation parameters; For scale parameters; These are the vertical translation parameters; The vertical coordinate on the catenary model. The x-coordinate on the catenary model. represent and The functional relationship;

[0093] The slope of any point on the catenary curve is:

[0094] ;

[0095] At the suspension point, we have:

[0096] ;

[0097] In the formula, The horizontal distance;

[0098] The height difference between the suspension points of the left and right towers for:

[0099] ;

[0100] In the formula, The x-coordinate is The vertical axis of time; The x-coordinate is The vertical axis of time;

[0101] Using the properties of hyperbolic functions, We can obtain:

[0102] ;

[0103] Then the infinitesimal element of arc length for:

[0104] ;

[0105] Therefore, the actual arc length of the conductor within each span for:

[0106] .

[0107] Step (3) specifically refers to:

[0108] Will Substituting into the slope expression, we get:

[0109] ;

[0110] In the formula, For scale parameters; and The suspension angle of the line between two adjacent towers;

[0111] The slope expression is:

[0112] ;

[0113] In the formula, The horizontal distance;

[0114] Calculate the elevation difference between the suspension points of adjacent towers :

[0115] ;

[0116] therefore:

[0117] ;

[0118] Will Substituting into the arc length expression, we get:

[0119] ;

[0120] The arc length expression is:

[0121] ;

[0122] The total arc length of the line is the equivalent path length. for:

[0123] ;

[0124] In the formula, This represents the number of segments representing the horizontal distance between two fault monitoring nodes;

[0125] Equivalent propagation speed for:

[0126] ;

[0127] In the formula, For adjacent towers Horizontal clearance; For the standard traveling wave propagation speed of overhead lines, take .

[0128] Step (4) specifically refers to: processing the acquired current traveling wave signal Perform phase-mode transformation to extract the linear mode traveling wave component; perform multi-resolution wavelet transform on the linear mode traveling wave component, detect the modulus maxima in the 3rd to 5th decomposition layers, and identify the first one exceeding the threshold. The time corresponding to the modulus maximum point is determined as the arrival time of the traveling wave. ;

[0129] The threshold for:

[0130] ;

[0131] in, For coefficients, ; This is the effective value of the line load current;

[0132] Let the nearest monitoring nodes at both ends of the fault section be and , The arrival time of the traveling wave is , The arrival time of the traveling wave is Then the distance from the fault point The path distance is the location of the fault. for:

[0133] ;

[0134] In the formula, For monitoring nodes and The distance between them;

[0135] Distance from Fault path distance for:

[0136] .

[0137] In summary, this invention significantly improves positioning accuracy: through real-time sag-temperature feedback, it eliminates path errors caused by sag, theoretically reducing positioning errors caused by sag from hundreds of meters to less than 20 meters; it achieves closed-loop adaptive system operation: sag-tilt angle sensing data is deeply integrated with the traveling wave positioning algorithm to form a closed-loop architecture of "perception-computation-correction," enabling it to cope with sudden weather changes and line condition changes during heavy load operation without manual intervention; it provides uncertainty quantification: while outputting positioning results, it provides confidence intervals to assist maintenance personnel in determining the patrol range and improve on-site handling efficiency; and it features wide dynamic range hardware acquisition: the dual-range Rogowski coil current sensor design simultaneously accommodates low-resistance short-circuit large signals and high-resistance grounding weak signals, expanding the system's fault detection applicability.

[0138] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for arc length calibration and dynamic fault location of transmission lines based on real-time feedback of suspension angle, characterized in that: The method includes the following steps in sequence: (1) Multiple distributed monitoring nodes are set up along the transmission line in each span. Each distributed monitoring node synchronously collects the conductor suspension angle, temperature, altitude and current traveling wave signal at its span. The distributed monitoring nodes include fault monitoring nodes and tilt angle and temperature monitoring nodes. (2) Based on the conductor suspension angle and altitude collected at each span, and using the catenary model, calculate the actual arc length of the conductor within each span. ; (3) The actual arc length of the conductor within each span. By summing the results, the equivalent path length of the traveling wave propagation between adjacent distributed monitoring nodes can be obtained. And based on the equivalent path length Calculate the equivalent propagation speed of a traveling wave. ; (4) When any fault monitoring node detects a sudden change in the current traveling wave signal, extract the arrival time of the traveling wave of the fault monitoring node, select the nearest fault monitoring node at both ends of the fault interval, and use the equivalent propagation speed The location of the fault point is calculated using the two-ended traveling wave location formula based on the arrival time difference of the traveling wave. ; (5) Locate the fault point The system compares the data with the tower coordinate database, i.e., the database of the monitoring center, outputs the tower segment number where the fault occurred and the distance to the nearest tower, and reports it to the monitoring center.

2. The method for transmission line arc length calibration and dynamic fault location based on real-time suspension angle feedback according to claim 1, characterized in that: Step (1) specifically refers to: along Transmission lines according to Distributed monitoring nodes are arranged at intervals; the tilt and temperature monitoring nodes are distributed between two adjacent fault monitoring nodes and close to the suspension point of the conductor on the tower. The horizontal span between adjacent towers is provided by the tower coordinate database. The fault monitoring nodes, tilt and temperature monitoring nodes are all clamped on the conductor. The fault monitoring node includes a dual-range Rogowski coil current sensor, a first tilt sensor, a first temperature sensor, a high-speed ADC, a first low-speed ADC, a second low-speed ADC, a first computing processing unit, a first communication module, and a BeiDou / GPS dual-mode timing module. The output of the dual-range Rogowski coil current sensor is connected to the input of the high-speed ADC, the first tilt sensor is connected to the input of the first low-speed ADC, the first temperature sensor is connected to the input of the second low-speed ADC, and the outputs of the high-speed ADC, the first low-speed ADC, and the second low-speed ADC are all connected to the input of the first computing processing unit. The first computing processing unit communicates bidirectionally with the first communication module and the BeiDou / GPS dual-mode timing module, respectively. The tilt and temperature monitoring node includes a second tilt sensor, a second temperature sensor, a third low-speed ADC, a fourth low-speed ADC, a second computing processing unit, and a second communication module. The output of the second tilt sensor is connected to the input of the third low-speed ADC, the output of the second temperature sensor is connected to the input of the fourth low-speed ADC, both the third and fourth low-speed ADCs are connected to the input of the second computing unit, and the second computing unit communicates bidirectionally with the second communication module. The conductor suspension angle is collected by an inclination sensor, the temperature is collected by a temperature sensor, and the current traveling wave signal is collected by a dual-range Rogowski coil current sensor. The altitude of each tower is stored in the database of the monitoring center.

3. The method for transmission line arc length calibration and dynamic fault location based on real-time suspension angle feedback according to claim 1, characterized in that: Step (2) specifically refers to: knowing the adjacent towers horizontal gap Altitude of adjacent tower suspension points and The suspension angle of the line between two adjacent towers and ;in, For the left tower, For the right tower; Calculate the elevation difference between the suspension points of adjacent towers : ； With the left tower The suspension point is the origin, and the horizontal direction to the right is... The positive direction of the axis is vertically upward. If the axis is in the positive direction, then the coordinates of the suspension point of the left tower are: The coordinates of the suspension point of the right tower are ; The shape of the line is a catenary, and the model of a catenary is represented as follows: ； In the formula, These are the horizontal translation parameters; For scale parameters; These are the vertical translation parameters; The vertical coordinate on the catenary model. The x-coordinate on the catenary model. represent and The functional relationship; The slope of any point on the catenary curve is: ； At the suspension point, we have: ； In the formula, The horizontal distance; The height difference between the suspension points of the left and right towers for: ； In the formula, The x-coordinate is The vertical axis of time; The x-coordinate is The vertical axis of time; Using the properties of hyperbolic functions, We can obtain: ； Then the infinitesimal element of arc length for: ； Therefore, the actual arc length of the conductor within each span for: 。 4. The method for transmission line arc length calibration and dynamic fault location based on real-time suspension angle feedback according to claim 1, characterized in that: Step (3) specifically refers to: Will Substituting into the slope expression, we get: ； In the formula, For scale parameters; and The suspension angle of the line between two adjacent towers; The slope expression is: ； In the formula, The horizontal distance; Calculate the elevation difference between the suspension points of adjacent towers : ； therefore: ； Will Substituting into the arc length expression, we get: ； The arc length expression is: ； The total arc length of the line is the equivalent path length. for: ； In the formula, This represents the number of segments representing the horizontal distance between two fault monitoring nodes; Equivalent propagation speed for: ； In the formula, For adjacent towers Horizontal clearance; For the standard traveling wave propagation speed of overhead lines, take .

5. The method for transmission line arc length calibration and dynamic fault location based on real-time suspension angle feedback according to claim 1, characterized in that: Step (4) specifically refers to: processing the acquired current traveling wave signal Perform phase-mode transformation to extract the linear mode traveling wave component; perform multi-resolution wavelet transform on the linear mode traveling wave component, detect the modulus maxima in the 3rd to 5th decomposition layers, and identify the first one exceeding the threshold. The time corresponding to the modulus maximum point is determined as the arrival time of the traveling wave. ; The threshold for: ； in, For coefficients, ; This is the effective value of the line load current; Let the nearest monitoring nodes at both ends of the fault section be and , The arrival time of the traveling wave is , The arrival time of the traveling wave is Then the distance from the fault point The path distance is the location of the fault. for: ； In the formula, For monitoring nodes and The distance between them; Distance from Fault path distance for: 。

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