Icing detection method for power transmission line

Abstract

The invention discloses a power transmission line icing detection method, and belongs to the field of power transmission lines. In order to solve the problems that only partial ice coating calculation can be carried out on ice coating of a power transmission line through an image, the influence of ice coating on the whole line in a span cannot be judged, and meanwhile, the applicability of ice coating detection is improved. A plurality of sensors such as the first line detection equipment, the second line detection equipment, the first tower positioning equipment and the second tower positioning equipment are arranged. According to the coordinates of the plurality of sensors, in combination with a power transmission line parabolic model, the horizontal stress of the line and the vertical stress of a suspension point as well as the icing load and the icing average thickness of the whole span under the conditions with ice and without wind and without ice and without wind are obtained in real time, and the influence of icing on the power transmission line is determined more comprehensively.

Description

Technical Field

[0001] The present invention relates to the field of power transmission lines, and in particular to a method for detecting ice coating on a power transmission line. Background Art

[0002] The normal operation of power transmission lines is related to people's daily life and industrial production, and is an important foundation for economic development. In recent years, abnormal weather has frequently occurred, and ice has often appeared on power transmission lines. Ice on power transmission lines can easily increase arc sag and cause discharge accidents, and excessive tension can cause line disconnection. More seriously, it may cause tower collapse accidents. Therefore, ice detection on power transmission lines is particularly important.

[0003] At present, ice detection for transmission lines mostly uses image analysis to determine whether ice has formed on the conductors. Based on pixel processing at the edges of un-iced conductors and iced conductors, the ice thickness is calculated to detect ice on the transmission lines.

[0004] When using image and analysis technology to detect ice on transmission lines, due to the image shooting angle and the long length of the line, only part of the line's iced area can be detected, and it is impossible to make an accurate judgment on the ice impact of the entire line. In addition, using tension to detect the ice impact of the entire line requires the installation of tension sensors on the tension insulators, which is complicated to operate and not conducive to promotion and application. Summary of the invention

[0005] In order to solve the problem that only partial icing calculation can be performed on the icing of transmission lines through images, and the impact of icing on the entire line within the span cannot be determined, and at the same time improve the applicability of icing detection, the present invention provides a transmission line icing detection method, which can obtain the icing load and average icing thickness of the entire span in real time, and more comprehensively determine the impact of icing on the transmission line.

[0006] The present invention provides the following technical solutions:

[0007] A method for detecting ice coating on a power transmission line, wherein a first pole tower positioning device and a second pole tower positioning device are respectively installed on adjacent first pole towers and second pole towers, and a first line detection device and a second line detection device are respectively installed at two different positions of a power transmission line between the adjacent first pole towers and the second pole towers;

[0008] The first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device all include a positioning module, a wireless transmission module and a temperature and humidity detection module, and the first pole tower positioning device and the second pole tower positioning device also include a wind speed detection module;

[0009] The method comprises:

[0010] S10: Detect the ambient temperature, humidity and wind speed in real time through the temperature and humidity detection module and the wind speed detection module, and locate the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device in real time through the positioning module;

[0011] S20: Establishing a spatial rectangular coordinate system, and converting the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device, and the second pole tower positioning device into three-dimensional spatial coordinates;

[0012] S30: When the temperature is greater than 0 degrees, the humidity is lower than the set humidity threshold, and the wind speed is lower than the set first wind speed threshold, it is determined to be an ice-free and windless state; the deadweight load ratio of the transmission line is calculated;

[0013] S40: When the temperature is not greater than 0 degrees, the humidity is not less than the set humidity threshold, and the wind speed is not less than the set first wind speed threshold and not greater than the set second wind speed threshold, it is determined to be an ice-free state; the ice load and ice thickness of the transmission line in the ice-free state are calculated;

[0014] S50: When the temperature is not greater than 0 degrees, the humidity is not lower than the set humidity threshold, and the wind speed is not lower than the set second wind speed threshold, it is judged to be in an icy and windy state; the ice load and ice thickness of the transmission line in the icy and windy state are calculated.

[0015] Further, the S20 includes:

[0016] S21: Taking the transmission line suspension point A on the first tower as the origin, the direction parallel to the transmission line as the Y axis, the vertical direction as the Z axis, and the direction perpendicular to the Y axis and the Z axis as the X axis, establish a spatial rectangular coordinate system;

[0017] S22: converting the longitude and latitude coordinates obtained by positioning modules of the first line detection device, the second line detection device, the first pole tower positioning device, and the second pole tower positioning device into three-dimensional space coordinates according to the established spatial rectangular coordinate system;

[0018] S23: According to the relative position relationship between the first tower positioning device and the second tower positioning device and the transmission line suspension points A and B on the first tower and the second tower, the three-dimensional spatial coordinates of the transmission line suspension point B on the second tower, the transmission line span l and the height difference h of the transmission line suspension points A and B are calculated.

[0019] Further, the S30 includes:

[0020] S31: Calculate the transmission line according to the parabola model to obtain the sag formula of any point on the transmission line;

[0021]

[0022] Where y is the Y-axis coordinate of any point on the transmission line, z is the sag value of the transmission line when the Y-axis coordinate is y, β is the height difference angle between the suspension points of the transmission line at the adjacent first tower and the second tower, σ0 and γ are the horizontal stress and specific load of the transmission line respectively;

[0023]

[0024] S32: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice-free and wind-free state into the sag formula, obtaining the horizontal stress σ0 and the specific load γ of the transmission line in the ice-free and wind-free state, and calculating the deadweight specific load g of the transmission line in the ice-free and wind-free state;

[0025] g=γ*A

[0026] Where A is the cross-sectional area of ​​the transmission line.

[0027] Furthermore, the S30 further includes:

[0028] S33: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the absence of ice and wind A ,σB;

[0029]

[0030]

[0031] Among them, l oa and l ob are the horizontal distances from the lowest point of the transmission line to the suspension points A and B of the transmission line respectively;

[0032]

[0033]

[0034] Further, the S40 includes:

[0035] S41: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice-free state into the sag formula, obtaining the horizontal stress σ1 and the specific load γ1 of the transmission line in the ice-free state, and calculating the conductor load g2 of the transmission line in the ice-free state;

[0036] g2=γ1*A

[0037] S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the presence of ice and no wind C , σ D ;

[0038] S43: When When the ice load g1 of the transmission line is in the state of ice and no wind, the formula g2=g+g1 is used to calculate the ice load g1 of the transmission line in the state of ice and no wind, and the formula g1=27.73δ(δ+d)×10 -3 Calculate the ice thickness δ1;

[0039] Where d is the diameter of the transmission line.

[0040] Further, the S50 includes:

[0041] S51: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the icy and windy state into the sag formula, obtaining the horizontal stress σ2 and the specific load γ2 of the transmission line in the icy and windy state, and calculating the conductor load g3 of the transmission line in the icy and windy state;

[0042] g3=γ2*A

[0043] S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line under ice and wind conditions E , σ F ;

[0044] S44: By formula Calculate the ice load g6 of the transmission line under the condition of ice and wind, and use the formula g6 = 27.73δ(δ+d)×10 -3 Calculate the ice thickness δ2;

[0045] Among them, g5 = g + g6, g4 = 0.625v 2 daμ sc ×10 -3 , v is the wind speed, a is the wind pressure unevenness coefficient of the transmission line, μ sc is the wire shape coefficient of the transmission line.

[0046] Furthermore, the method further comprises:

[0047] S60: Compare the horizontal stresses σ0, σ1, σ2 of the transmission line in the ice-free and windless state, the ice-free and windy state with the maximum tension F that the transmission line can withstand, and issue a warning signal when σ0, σ1, σ2 exceed a first set percentage of the maximum tension F.

[0048] Furthermore, the method further comprises:

[0049] S70: The vertical stress σ of the transmission line suspension points A and B under the conditions of ice and no wind, ice and no wind, and ice and wind. A , σ B , σ C , σ D , σE , σ F Compared with the maximum pressure F1 that the insulator can withstand, when σ A , σ B , σ C , σ D , σ E , σ F When the pressure exceeds the second set percentage of the maximum pressure F1, an early warning signal is issued.

[0050] The present invention has the following beneficial effects:

[0051] In order to solve the problem that only partial ice calculation can be performed on the ice of the transmission line through images, and the influence of ice on the entire line within the span cannot be judged, and at the same time, the applicability of ice detection is improved, the present invention sets a plurality of sensors such as a first line detection device, a second line detection device, a first pole tower positioning device and a second pole tower positioning device. According to the coordinates of the plurality of sensors, combined with the parabolic model of the transmission line, the horizontal stress of the line and the vertical stress of the suspension point are obtained in real time, as well as the ice load and average ice thickness of the entire span under the conditions of ice without wind and ice without wind, so as to more comprehensively determine the influence of ice on the transmission line. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the physical equipment on which the power transmission line ice detection method of the present invention is based;

[0053] Figure 2 The present invention is a flow chart of a method for detecting ice coating on a power transmission line. DETAILED DESCRIPTION

[0054] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0055] The embodiment of the present invention provides a method for detecting ice coating on a power transmission line. Figure 1 As shown, a first tower positioning device 1 and a second tower positioning device 2 are respectively installed on adjacent first towers 100 and second towers 200, and a first line detection device 3 and a second line detection device 4 are respectively installed at two different positions of a transmission line 5 between the adjacent first towers 100 and second towers 200.

[0056] The first line detection device 3, the second line detection device 4, the first pole tower positioning device 1 and the second pole tower positioning device 2 all include a positioning module (such as an RTK positioning module), a wireless transmission module and a temperature and humidity detection module, and if necessary, a wireless transmission module, a power module, etc. The first pole tower positioning device 1 and the second pole tower positioning device 2 also include a wind speed detection module.

[0057] The first line detection device 3 and the second line detection device 4 are installed on the transmission line, wherein the RTK positioning module provides millimeter-level positioning, the temperature and humidity module detects the temperature and humidity around the line, the power module is composed of a mutual inductance core, a solar panel, a supercapacitor, and a lithium battery, and the line mutual inductance obtains the energy required for the equipment to work. The wireless transmission module can transmit the equipment positioning information, temperature and humidity information, and power information to the data server through 4G / 5G communication.

[0058] The first pole tower positioning device 1 and the second pole tower positioning device 2 are respectively installed on the first pole tower 100 and the second pole tower 200 on both sides, and the horizontal distance a, vertical distance b and distance e along the line between the first pole tower positioning device 1 and the wire suspension point A on one side, and the horizontal distance c, vertical distance d and distance f along the line between the second pole tower positioning device 2 and the wire suspension point B on one side are measured by measuring instruments. The RTK positioning device provides millimeter-level positioning information, the temperature and humidity module obtains the ambient temperature and humidity, the wind speed detection module can detect the surrounding wind speed information, the power module is composed of solar panels and lithium batteries, and the wireless transmission module can transmit the positioning information, ambient temperature and humidity information, wind speed information, and equipment power information to the data server through 4G / 5G communication.

[0059] Based on the above structure, the ice detection method is as follows: Figure 2 Said, including:

[0060] S10: Detect the ambient temperature, humidity and wind speed in real time through the temperature and humidity detection module and the wind speed detection module, and locate the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device in real time through the positioning module.

[0061] S20: Establishing a spatial rectangular coordinate system, and converting the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device, and the second pole tower positioning device into three-dimensional spatial coordinates.

[0062] One implementation of this step includes:

[0063] S21: With the transmission line suspension point A on the first tower as the origin, the direction parallel to the transmission line as the Y axis, the vertical direction as the Z axis, and the direction perpendicular to the Y axis and Z axis as the X axis, a spatial rectangular coordinate system is established, such as Figure 1 shown.

[0064] S22: converting the longitude and latitude coordinates obtained by positioning modules of the first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device into three-dimensional space coordinates according to the established spatial rectangular coordinate system.

[0065] Exemplarily, the three-dimensional spatial coordinates of the first pole tower positioning device 1, the second pole tower positioning device 2, the first line detection device 3, and the second line detection device 4 are (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), and (x4, y4, z4), respectively.

[0066] S23: According to the relative position relationship between the first tower positioning device and the second tower positioning device and the transmission line suspension points A and B on the first tower and the second tower, the three-dimensional spatial coordinates of the transmission line suspension point B on the second tower, the transmission line span l and the height difference h of the transmission line suspension points A and B are calculated.

[0067] The horizontal distance a, vertical distance b and distance e along the line between the first pole tower positioning device 1 and the wire suspension point A on one side are known, and the horizontal distance c, vertical distance d and distance f along the line between the second pole tower positioning device 2 and the wire suspension point B on one side are known. The translation coordinates of the line suspension points A and B on both sides of the pole tower can be obtained as (x1+a, y1-e, z1+b) and (x2+c, y2+f, z2+d).

[0068] According to the coordinates of the road suspension points A and B, the line detection distance can be obtained The height difference between suspension points A and B is h=|z2+d-z1-b|.

[0069] S30: When the temperature is greater than 0 degrees, the humidity is lower than the set humidity threshold, and the wind speed is less than the set first wind speed threshold, it is judged to be an ice-free and windless state; and the deadweight load ratio of the transmission line is calculated.

[0070] For example, the humidity threshold may be 85%, and the first wind speed threshold may be a value close to zero.

[0071] As an implementation method, the specific process of S30 includes:

[0072] S31: Calculate the transmission line according to the parabola model to obtain the sag formula of any point on the transmission line.

[0073]

[0074] Among them, y is the Y-axis coordinate of any point of the transmission line, z is the sag value of the transmission line when the Y-axis coordinate is y, β is the height difference angle of the suspension point of the transmission line between the adjacent first tower and the second tower, σ0 and γ are the horizontal stress and specific load of the transmission line respectively.

[0075]

[0076] S32: Substitute the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice-free and wind-free state into the sag formula to obtain the horizontal stress σ0 and the specific load γ of the transmission line in the ice-free and wind-free state, and calculate the deadweight specific load g of the transmission line in the ice-free and wind-free state.

[0077] g=γ*A

[0078] Among them, if according to Figure 1 The coordinate system is established, and the y value of the three-dimensional space coordinates of the first line detection device and the second line detection device is substituted into the parameter y of the sag formula, and the absolute value of the z value of the three-dimensional space coordinates of the first line detection device and the second line detection device is substituted into the parameter z of the sag formula. Since β can be calculated by trigonometric functions through the transmission line span l and the height difference h between the transmission line suspension points A and B, the horizontal stress σ0 and the specific load γ of the transmission line in the ice-free and windless state can be obtained by substituting into the sag value formula.

[0079] A is the cross-sectional area of ​​the transmission line, which can be obtained through the line construction drawings, so the deadweight load g of the transmission line can be calculated.

[0080] S33: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the absence of ice and wind A , σ B ;

[0081]

[0082]

[0083] Among them, l oa and l ob They are the horizontal distances from the lowest point o of the transmission line to the suspension points A and B of the transmission line respectively.

[0084]

[0085]

[0086] In this step, the horizontal distance formula from the lowest point of the line to the suspension point can be used to calculate l oa , l ob . According to the vertical component stress formula of the transmission line suspension point: oblique parabola equation The vertical stress σ at points A and B under windless and ice-free conditions can be obtained A , σ B .

[0087] S40: When the temperature is not greater than 0 degrees, the humidity is not lower than the set humidity threshold, the wind speed is not less than the set first wind speed threshold and not greater than the set second wind speed threshold, it is judged to be an ice-free state; calculate the ice load and ice thickness of the transmission line in the ice-free state.

[0088] For example, when the temperature is not greater than 0 degrees and the humidity is not lower than the set humidity threshold, it is very easy for the line to be covered with ice. At this time, the second wind speed threshold can be a value of about 1m / S.

[0089] A specific implementation of S40 includes:

[0090] S41: Substitute the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice and windless state into the sag formula to obtain the horizontal stress σ1 and the specific load γ1 of the transmission line in the ice and windless state, and calculate the conductor load g2 of the transmission line in the ice and windless state.

[0091] g2=γ1*A

[0092] This step is similar to S32, except that the coordinates under the ice and windless state are substituted, and the horizontal stress σ1 and the specific load γ1 under the ice and windless state are obtained. Then, based on the cross-sectional area A of the transmission line, the conductor load g2 under the ice and windless state can be calculated.

[0093] S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the presence of ice and no wind C , σ D .

[0094] This step is similar to S33, except that the specific load in the formula is γ1, and the specific process will not be repeated here.

[0095] S43: When When the ice load g1 of the transmission line is in the state of ice and no wind, the formula g2=g+g1 is used to calculate the ice load g1 of the transmission line in the state of ice and no wind, and the formula g1=27.73δ(δ+d)×10 -3 Calculate the ice thickness δ1.

[0096] Where d is the diameter of the transmission line, which can be obtained from the line construction drawings.

[0097] when When the vertical stress of the line increases, the wind load caused by the wind speed is small, and the conductor load is mainly composed of the deadweight load and the ice load, that is, g2 = g + g1. g1 is the ice load, g is the deadweight load of the conductor, and the ice load g1 is obtained.

[0098] According to the formula g1 = 27.73δ(δ+d)×10 -3, δ is the ice thickness of the wire, d is the wire diameter, and the average ice thickness δ1 within the span under this environment is calculated.

[0099] S50: When the temperature is not greater than 0 degrees, the humidity is not lower than the set humidity threshold, and the wind speed is not lower than the set second wind speed threshold, it is judged to be in an icy and windy state; the ice load and ice thickness of the transmission line in the icy and windy state are calculated.

[0100] A specific implementation of S50 includes:

[0101] S51: Substitute the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the icy and windy state into the sag formula to obtain the horizontal stress σ2 and the specific load γ2 of the transmission line in the icy and windy state, and calculate the conductor load g3 of the transmission line in the icy and windy state.

[0102] g3=γ2*A

[0103] This step is similar to S32 and will not be described in detail.

[0104] S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line under ice and wind conditions E , σ F .

[0105] This step is similar to S33 and will not be described in detail.

[0106] S44: By formula Calculate the ice load g6 of the transmission line under the condition of ice and wind, and use the formula g6 = 27.73δ(δ+d)×10 -3 Calculate the ice thickness δ2.

[0107] Among them, g5 = g + g6, g4 = 0.625v 2 daμ sc ×10 -3 , v is the wind speed, a is the wind pressure unevenness coefficient of the transmission line, μ sc is the wire shape factor of the transmission line, a and μ sc It can be obtained from the "Technical Code for Design of Overhead Transmission Lines".

[0108] In order to solve the problem that only partial ice calculation can be performed on the ice of the transmission line through images, and the influence of ice on the entire line within the span cannot be judged, and at the same time, the applicability of ice detection is improved, the present invention sets a plurality of sensors such as a first line detection device, a second line detection device, a first pole tower positioning device and a second pole tower positioning device. According to the coordinates of the plurality of sensors, combined with the parabolic model of the transmission line, the horizontal stress of the line and the vertical stress of the suspension point are obtained in real time, as well as the ice load and average ice thickness of the entire span under the conditions of ice without wind and ice without wind, so as to more comprehensively determine the influence of ice on the transmission line.

[0109] At the same time, the present invention can also issue an alarm prompt and make a quick response when the horizontal stress and vertical stress exceed the set stress threshold. The specific method includes:

[0110] S60: Compare the horizontal stresses σ0, σ1, σ2 of the transmission line in the ice-free and windless state, the ice-free and windy state with the maximum tension F that the transmission line can withstand, and when σ0, σ1, σ2 exceed a first set percentage of the maximum tension F, send a warning signal to the server.

[0111] S70: The vertical stress σ of the transmission line suspension points A and B under the conditions of ice and no wind, ice and no wind, and ice and wind. A , σ B , σ C , σ D , σ E , σ F Compared with the maximum pressure F1 that the insulator can withstand, when σ A , σ B , σ C , σ D , σ E , σ F When the second set percentage of the maximum pressure F1 is exceeded, an early warning signal is sent to the server.

[0112] The transmission line icing detection system also includes a data server and a monitoring platform. The data server mainly receives data information from line detection equipment, tower positioning equipment, and monitoring equipment, and calculates the received data information according to the transmission line icing detection method, and calculates the horizontal stress of the transmission line and the horizontal stress of the mounting points on both sides under various temperatures, humidity, wind speed, and whether there is icing. It also calculates the ice thickness in the case of icing, and the alternating changes of the icing load and the icing wind load in the case of wind and ice. The server stores data according to the "storage days" instruction specified by the platform. The server receives the "conductor stress threshold" and "suspension point stress threshold" set by the platform, and compares the actually calculated conductor level with the conductor maximum tension percentage and the conductor stress threshold. If it exceeds the set threshold, an alarm signal is issued. Similarly, if the suspension point stress exceeds the set threshold, an alarm signal is issued.

[0113] The monitoring platform is used to display the operating status of line detection equipment, tower positioning equipment, and monitoring equipment, set the operating frequencies of the three types of equipment, set the data retention date of the data server, display the horizontal stress of the line and the vertical stress of the line suspension point when the conductor is free of ice and covered with ice without wind, and when the conductor is covered with ice and wind, the ice thickness of the line with ice but no wind, the changes in the ice load and ice wind load under ice and wind, set the horizontal stress alarm threshold and the vertical stress alarm threshold of the suspension point, and after receiving the alarm information, issue an alarm to remind the monitoring personnel that the stress exceeds the limit.

[0114] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting ice coating on a power transmission line, characterized in that: A first pole tower positioning device and a second pole tower positioning device are respectively installed on adjacent first pole towers and second pole towers, and a first line detection device and a second line detection device are respectively installed at two different positions of a transmission line between the adjacent first pole towers and the second pole towers; The first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device all include a positioning module, a wireless transmission module and a temperature and humidity detection module, and the first pole tower positioning device and the second pole tower positioning device also include a wind speed detection module; The method comprises: S10: Detect the ambient temperature, humidity and wind speed in real time through the temperature and humidity detection module and the wind speed detection module, and locate the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device and the second pole tower positioning device in real time through the positioning module; S20: Establishing a spatial rectangular coordinate system, and converting the longitude and latitude coordinates of the first line detection device, the second line detection device, the first pole tower positioning device, and the second pole tower positioning device into three-dimensional spatial coordinates; S30: When the temperature is greater than 0 degrees, the humidity is lower than the set humidity threshold, and the wind speed is lower than the set first wind speed threshold, it is determined to be an ice-free and windless state; the deadweight load ratio of the transmission line is calculated; S40: When the temperature is not greater than 0 degrees, the humidity is not less than the set humidity threshold, and the wind speed is not less than the set first wind speed threshold and not greater than the set second wind speed threshold, it is determined to be an ice-free state; the ice load and ice thickness of the transmission line in the ice-free state are calculated; S50: When the temperature is not greater than 0 degrees, the humidity is not lower than the set humidity threshold, and the wind speed is not lower than the set second wind speed threshold, it is judged to be in an icy and windy state; the ice load and ice thickness of the transmission line in the icy and windy state are calculated.

2. The method for detecting ice coating on a power transmission line according to claim 1, characterized in that: The S20 includes: S21: Taking the transmission line suspension point A on the first tower as the origin, the direction parallel to the transmission line as the Y axis, the vertical direction as the Z axis, and the direction perpendicular to the Y axis and the Z axis as the X axis, establish a spatial rectangular coordinate system; S22: converting the longitude and latitude coordinates obtained by positioning modules of the first line detection device, the second line detection device, the first pole tower positioning device, and the second pole tower positioning device into three-dimensional space coordinates according to the established spatial rectangular coordinate system; S23: According to the relative position relationship between the first tower positioning device and the second tower positioning device and the transmission line suspension points A and B on the first tower and the second tower, the three-dimensional spatial coordinates of the transmission line suspension point B on the second tower, the transmission line span l and the height difference h of the transmission line suspension points A and B are calculated.

3. The method for detecting ice coating on a power transmission line according to claim 2, characterized in that: The S30 includes: S31: Calculate the transmission line according to the parabola model to obtain the sag formula of any point on the transmission line; Where y is the Y-axis coordinate of any point on the transmission line, z is the sag value of the transmission line when the Y-axis coordinate is y, β is the height difference angle between the suspension points of the transmission line at the adjacent first tower and the second tower, σ0 and γ are the horizontal stress and specific load of the transmission line respectively; S32: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice-free and wind-free state into the sag formula, obtaining the horizontal stress σ0 and the specific load γ of the transmission line in the ice-free and wind-free state, and calculating the deadweight specific load g of the transmission line in the ice-free and wind-free state; g=γ*A Where A is the cross-sectional area of ​​the transmission line.

4. The method for detecting ice coating on a power transmission line according to claim 3, characterized in that: The S30 further includes: S33: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the absence of ice and wind A , σ B ; Among them, l oa and l ob are the horizontal distances from the lowest point of the transmission line to the suspension points A and B of the transmission line respectively; 。 5. The method for detecting ice coating on a power transmission line according to claim 4, characterized in that: The S40 includes: S41: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the ice-free state into the sag formula, obtaining the horizontal stress σ1 and the specific load γ1 of the transmission line in the ice-free state, and calculating the conductor load g2 of the transmission line in the ice-free state; g2=γ1*A S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line in the presence of ice and no wind C , σ D ; S43: When When the ice load g1 of the transmission line is in the state of ice and no wind, the formula g2=g+g1 is used to calculate the ice load g1, and the formula g1=27.73δ(δ+d)×10 -3 Calculate the ice thickness δ1; Where d is the diameter of the transmission line.

6. The method for detecting ice coating on a power transmission line according to claim 5, characterized in that: The S50 includes: S51: Substituting the three-dimensional spatial coordinates of the first line detection device and the second line detection device in the icy and windy state into the sag formula, obtaining the horizontal stress σ2 and the specific load γ2 of the transmission line in the icy and windy state, and calculating the conductor load g3 of the transmission line in the icy and windy state; g3=γ2*A S42: Calculate the vertical stress σ at the suspension points A and B of the transmission line under ice and wind conditions E , σ F ; S44: By formula Calculate the ice load g6 of the transmission line under the condition of ice and wind, and use the formula g6 = 27.73δ(δ+d)×10 -3 Calculate the ice thickness δ2; Among them, g5 = g + g6, g4 = 0.625v 2 daμ sc ×10 -3 , v is the wind speed, a is the wind pressure unevenness coefficient of the transmission line, μ sc is the wire shape coefficient of the transmission line.

7. The method for detecting ice coating on a power transmission line according to claim 6, characterized in that: The method further comprises: S60: Compare the horizontal stresses σ0, σ1, σ2 of the transmission line in the ice-free and windless state, the ice-free and windy state with the maximum tension F that the transmission line can withstand, and issue a warning signal when σ0, σ1, σ2 exceed a first set percentage of the maximum tension F.

8. The method for detecting ice coating on a power transmission line according to claim 7, characterized in that: The method further comprises: S70: The vertical stress σ of the transmission line suspension points A and B under the conditions of ice and no wind, ice and no wind, and ice and wind. A , σ B , σ C , σ D , σ E , σ F Compared with the maximum pressure F1 that the insulator can withstand, when σ A , σ B , σ C , σ D , σ E , σ F When the pressure exceeds the second set percentage of the maximum pressure F1, an early warning signal is issued.

Images