A safety range detection method for unmanned aerial vehicle inspection of power transmission lines

Abstract

The present invention discloses a method for detecting the safe range of a transmission line by a drone, comprising the following steps: Step 1, modeling a transmission tower in the transmission line, obtaining simulated measurement electric field data, and determining a safe distance according to the maximum field strength that the drone can withstand; Step 2, determining the safe distance of the drone's flight distance from the transmission line in combination with the electric field safety distance, the positioning error of the drone, and the size parameters; Step 3, combining the safety distance with the transmission line and the transmission tower model to determine the final inspection safety range and form an electronic fence. The present invention takes into account the spatial electric field distribution around the transmission line, determines that its distribution law is consistent to reduce deviations, and determines the flight range of the drone's inspection of the transmission tower in combination with other factors, establishes an electronic fence, and can obtain the position coordinates of the drone's cruising point based on the reconstructed model, which not only reduces the inspection distance, but also ensures safety while improving inspection efficiency.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicle (UAV) inspection flight safety, and in particular to a technology for determining a UAV safety inspection range based on electric field threats. Background Art

[0002] The continuous operation and safety of transmission lines are often threatened by various factors. Severe weather conditions such as strong winds, heavy rains, ice and snow and other extreme climate events may cause short circuits, ruptures or equipment damage in transmission lines, seriously affecting the reliability and continuity of power supply.

[0003] Traditional inspection methods for transmission lines usually rely on ground inspection personnel or helicopter flight inspections. However, these methods have some significant limitations, and the high cost of human resources makes these methods economically unsustainable. Ground inspections are limited by the complexity of terrain and remote areas, resulting in limited coverage, and many hidden problems are difficult to detect in a timely manner. Although helicopter flight inspections can cover a larger area, they are expensive and have questionable flight safety, which greatly affects work efficiency. Ground auxiliary equipment is also used for inspections;

[0004] For example, a public document with publication number CN205583855U, publication date September 14, 2016, and patent name "A smart patrol tool for power grid control duty places" discloses a smart patrol tool for power grid control duty places, including a main body, a moving device is arranged at the bottom of the main body, a connecting plate is arranged on one side of the main body, a wireless signal receiver is arranged on the top of the connecting plate, a telescopic device is arranged on the top of the main body, a turntable is arranged on the top of the telescopic device, and a video recorder is arranged on the top of the turntable.

[0005] Similar inspection tools have low inspection efficiency and small coverage, so we are currently seeking a more efficient, lower-cost and wider-coverage inspection method. The rapid development of drone technology provides a feasible way to solve the above problems. Drone inspection of power systems has the advantages of strong flexibility, wide coverage and high detection accuracy. Compared with traditional inspection methods, drone inspection saves a lot of human resources and cost investment, which is in line with the strategic concept of sustainable development.

[0006] Although drone inspections of power systems have improved efficiency, they have also introduced new challenges. There is a complex electric field environment near high-voltage power lines, which may interfere with the normal operation of drones and cause damage to internal electrical structures. This may cause drones to crash or collide with transmission towers, etc., which requires solving problems in electric field interference and flight safety to ensure the smooth progress of drone inspection operations.

[0007] Electromagnetic interference can be reduced by using anti-interference materials. To reduce damage caused by electric field distortion and tip discharge near the drone due to excessive electric field strength, a certain safe distance needs to be maintained from the transmission lines, mainly considering the safety distance caused by the electric field and the drone itself.

[0008] Therefore, the use of drones needs to be equipped with a safety range detection technology to make drone inspections more practical and feasible. Summary of the invention

[0009] The technical problem to be solved by the present invention is to achieve a method for determining the safe range of drone inspection operations based on a transmission tower model and the corresponding spatial distribution and change law of the power frequency electric field to address the flight safety issue of drone inspections.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is: a method for detecting the safety range of a transmission line by using a drone for inspection, comprising the following steps:

[0011] Step 1: Model the transmission towers in the transmission line, obtain simulated electric field data, and determine the safe distance based on the maximum field strength that the drone can withstand;

[0012] Step 2: Determine the safe distance between the UAV and the power transmission line based on the electric field safety distance, the positioning error and the size parameters of the UAV;

[0013] Step 3: Combine the safety distance with the transmission line and transmission tower model to determine the final inspection safety range and form an electronic fence.

[0014] In the step 1, ANSYS is used to simulate and calculate the superimposed electric field around the three-phase transmission line.

[0015] In step 1, the simulation calculation includes the following information:

[0016] Calculate the field strength of the A-phase transmission line at different phases from 0° to 180° in the horizontal direction 5m below the conductor;

[0017] Calculate the electric field around the transmission line in different directions with the same phase

[0018] The electric field strength at different phases within 10m on the right side of the transmission line is calculated, and multiple electric field strength-distance relationship curves are obtained.

[0019] The field strength threshold is set according to the maximum field strength that the drone can withstand. The position distance corresponding to 10kV of each curve is different. The maximum distance is taken to obtain the safe distance d affected by the electric field factor. E .

[0020] In step 2, the formula for determining the safe distance of drone inspection is as follows:

[0021] D=d E +d m +d n +a;

[0022] where d E d is the safety distance affected by electric field factors; m is the positioning error; a is the distance from the center of the drone to the rotation axis; d n is the distance flown within the communication delay time.

[0023] The d m It is determined by the maximum deviation value of the hovering accuracy of the UAV parameters and the RTK accuracy.

[0024] In step 3, the transmission tower model and the safety distance are combined and drawn on the modeling software.

[0025] In step 3, the specific steps of drawing are as follows:

[0026] 1) In a two-dimensional plane, connect the centers of the wires to obtain L1 and L2.

[0027] 2) Move L1 and L2 to the outside of the wire by a distance D to extend them to obtain L3 and L4.

[0028] 3) Connect the intersection points of the lines to get a closed polygon.

[0029] 4) The plane polygon is stretched by 2D length to obtain a 3D model covering the tower.

[0030] An electronic fence is formed by using a three-dimensional model as the boundary. If the drone approaches or crosses the electronic fence during flight, it will automatically adjust its flight attitude and will not enter the electronic fence.

[0031] The present invention takes into account the spatial electric field distribution around the transmission lines, determines that its distribution pattern is consistent to reduce deviations, and combines other factors to determine the flight range of the UAV for inspecting transmission towers. An electronic fence is established, and the position coordinates of the UAV cruising point can be obtained based on the reconstructed model, which not only reduces the inspection distance, but also ensures safety while improving inspection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The following is a brief description of the contents expressed in each figure in the specification of the present invention:

[0033] Figure 1 It is a schematic diagram of the simulation model of a 500kV double-circuit AC transmission line;

[0034] Figure 2 This is the horizontal electric field distribution diagram 5m below the conductor;

[0035] Figure 3It is the electric field distribution diagram in different directions around the wire;

[0036] Figure 4 It is a graph of the relationship between the horizontal electric field strength and the distance outside the conductor;

[0037] Figure 5 This is a schematic diagram of the electronic fence within the safety range of the transmission tower. DETAILED DESCRIPTION

[0038] The following is a further detailed description of the specific implementation methods of the present invention, such as the shape, structure, relative position and connection relationship between the various components involved, the function and working principle of each part, the manufacturing process and operation method, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0039] Method for determining the safe range of UAV inspection based on electric field information, such as Figure 1 As shown in the figure, taking the 500kV double-circuit three-phase transmission tower model as an example, the electric field data is simulated and calculated using the electromagnetic field mirror principle and the electric field superposition principle, and the safe distance is determined according to the maximum field strength that the drone can withstand. The specific steps include the following:

[0040] Step 1: Using a 500kV double-circuit three-phase transmission tower as a model, simulate and measure the electric field data, and determine the safe distance based on the maximum field strength that the drone can withstand;

[0041] The electric field strength at any point in the space around the transmission line can be calculated based on the principle of electromagnetic field superposition, and the superimposed electric field around the three-phase transmission line can be calculated using ANSYS simulation.

[0042] Calculate the field strength of the A-phase transmission line at different phases from 0° to 180° in the horizontal direction 5m below the conductor.

[0043] Calculate the electric field around the transmission line in different directions with the same phase.

[0044] It is determined that the electric field distribution law is consistent in space, and the electric field strength at different phases within 10m on the right side of the transmission line is calculated to obtain multiple electric field strength-distance relationship curves.

[0045] According to the maximum field strength that the drone can withstand (generally 10kV / m), the field strength threshold is set to 10kV / m. The position distance corresponding to 10kV in each curve is different. For safety considerations, the maximum distance is taken to obtain the safe distance d affected by the electric field factor. E .

[0046] Step 2: Determine the safe distance between the UAV and the power transmission line based on the electric field safety distance, the positioning error and size parameters of the UAV;

[0047] When the data is determined, the horizontal flight safety distance is determined based on the measured electric field safety distance and combined with the errors of other factors.

[0048] The formula for determining the safe distance for drone inspection is as follows:

[0049] D=d E +d m +d n +a

[0050] where d E d is the safety distance affected by electric field factors; m is the positioning error; a is the distance from the center of the drone to the rotation axis; d n is the distance flown within the communication delay time.

[0051] d m It is determined by the maximum deviation value of the hovering accuracy of the drone parameters and the RTK accuracy.

[0052] Step 3: Combine the safety distance with the transmission tower model to determine the final inspection safety range and form an electronic fence.

[0053] Combine the transmission tower model with the safety distance, simplify the originally complex transmission tower model, and draw it on the solidworks modeling software. The specific steps are as follows:

[0054] 1. On a two-dimensional plane, connect the centers of the wires to get L1 and L2, that is, connect the three points to each other to get L1 and L2;

[0055] 2. Shift L1 and L2 to the outside of the conductor by a distance D to obtain L3 and L4;

[0056] 3. Connect the intersection points of the straight lines to get a closed polygon;

[0057] 4. Stretch the plane polygon by 2D length to obtain a 3D model covering the tower.

[0058] This three-dimensional model is used as the boundary to form an electronic fence. If the drone approaches or crosses the electronic fence during flight, it will automatically adjust its flight attitude and will not enter the electronic fence.

[0059] like Figure 2 As shown in the figure, the simulation calculates the field strength of the A-phase transmission line at different phases from 0° to 180° in the horizontal direction 5m below the conductor. It can be seen that the electric field around the transmission line is symmetrically distributed, with the highest electric field strength directly below the conductor, and monotonically decreasing with increasing distance on both sides of the conductor.

[0060] like Figure 3As shown in the figure, the simulation calculates the electric field in different directions around the transmission line under the same phase. The electric field measured in each direction approximates a monotonically decreasing curve.

[0061] like Figure 4 As shown in the figure, the relationship between the horizontal electric field strength and the distance outside the conductor. Multiple curves correspond to different phases. The electric field strength threshold that the drone can withstand is 10kV / m. The upper limit of the electric field strength is set to 10kV / m. The safe distance under this threshold is obtained for each phase. To ensure sufficient safety margin, the maximum value is taken as the safe distance d affected by the electric field factor. E .

[0062] The present invention takes into account the spatial electric field distribution around the transmission lines, determines that its distribution pattern is consistent to reduce deviations, and combines other factors to determine the flight range of the UAV for inspecting transmission towers. An electronic fence is established, and the position coordinates of the UAV cruising point can be obtained based on the reconstructed model, which not only reduces the inspection distance, but also ensures safety while improving inspection efficiency.

[0063] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for detecting the safety range of a transmission line by using a drone, characterized in that: The following steps are involved: Step 1: Model the transmission towers in the transmission line, obtain simulated electric field data, and determine the safe distance based on the maximum field strength that the drone can withstand; Step 2: Determine the safe distance between the UAV and the power transmission line based on the electric field safety distance, the positioning error and the size parameters of the UAV; Step 3: Combine the safety distance with the transmission line and transmission tower model to determine the final inspection safety range and form an electronic fence; In step 1, the simulation calculation includes the following information: Calculate the field strength of the A-phase transmission line at different phases from 0° to 180° in the horizontal direction 5m below the conductor; Calculate the electric field in different directions around the transmission line under the same phase; Calculate the electric field strength at different phases within 10m on the right side of the transmission line and obtain multiple electric field strength-distance relationship curves; In step 2, the formula for determining the safe distance of drone inspection is as follows: D=d E +d m +d n +a; where d E d is the safety distance affected by electric field factors; m is the positioning error; a is the distance from the center of the drone to the rotation axis; d n is the distance flown during the communication delay time; The d m It is determined by the maximum deviation value of the hovering accuracy of the UAV parameters and the RTK accuracy; In step 3, the transmission tower model and the safety distance are combined and drawn on the modeling software; In step 3, the specific steps of drawing are as follows: 1) On a two-dimensional plane, connect the centers of the wires to obtain L1 and L2; 2) Shift L1 and L2 to the outside of the wire by a distance D to obtain L3 and L4; 3) Connect the intersection points of the straight lines to obtain a closed polygon; 4) The plane polygon is stretched by 2D length to obtain a 3D model covering the tower.

2. According to the method for detecting the safety range of a transmission line by inspecting it by an unmanned aerial vehicle according to claim 1, it is characterized in that: In the step 1, ANSYS is used to simulate and calculate the superimposed electric field around the three-phase transmission line.

3. According to the method for detecting the safety range of a transmission line by inspecting a transmission line by an unmanned aerial vehicle according to claim 2, it is characterized in that: The field strength threshold is set according to the maximum field strength that the drone can withstand. The position distance corresponding to 10kV of each curve is different. The maximum distance is taken to obtain the safe distance d affected by the electric field factor. E .

4. According to the method for detecting the safety range of a transmission line by inspecting it by a drone in accordance with claim 1, it is characterized by: An electronic fence is formed by using a three-dimensional model as the boundary. If the drone approaches or crosses the electronic fence during flight, it will automatically adjust its flight attitude and will not enter the electronic fence.

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