A method for verifying the electrical safety distance between a wind turbine and an overhead collector line

Abstract

A method for verifying the electrical safety distance between a wind turbine and an overhead collector line comprises the following steps: drawing a wind sweep circle diagram of a wind turbine blade tip; measuring the center distance between a wind turbine tower and an iron tower and the shortest distance between the center of the wind turbine tower and a collector line; determining the minimum free-air distance between the wind turbine and the overhead collector line, drawing a wind sweep surface diagram, and calculating the position of the overhead collector line on the wind sweep surface; drawing a cross-sectional diagram of the minimum free-air distance between the wind turbine and the overhead collector line; measuring the minimum free-air distance between the wind turbine and a ground wire of the overhead collector line and the minimum free-air distance between the wind turbine and a side conductor of the overhead collector line; and verifying the minimum free-air distance between the wind turbine and the ground wire of the overhead collector line and the minimum free-air distance between the wind turbine and a side conductor of the overhead collector line respectively; the present invention comprehensively considers the factors affecting the safety distance verification, thereby improving the accuracy of the verification result, and allows wind farm designers to quickly and easily make safety judgments on the layout and positioning of wind turbines and overhead collector lines.

Description

Technical Field

[0001] The invention relates to the technical field of wind farm design, and in particular to a method for checking the electrical safety distance between a wind turbine and an overhead collector line. Background Art

[0002] The design of a wind farm includes the site selection and layout of wind turbines and the design of collector lines. The layout of wind turbines in a wind farm should be based on a comprehensive consideration of the site's topography, morphology, and the location of existing facilities in the field, making full use of the site scope and selecting the layout method; and the row and column spacing of wind turbines should be reasonably determined based on the dominant wind direction in the field to reduce the impact of wind turbine wake. Overhead collector lines should be used as collector lines for wind farms. The selection of overhead collector line paths should be determined based on the layout of wind turbines and construction and maintenance roads, and mutual interference between wind turbines and overhead collector lines should be avoided during construction and maintenance. When the wind turbine is operating normally, it is required not to affect the safe operation of the overhead collector line, and the wind turbine blades and the side conductors and ground wires of the overhead collector line should meet sufficient electrical safety distances.

[0003] There is no mature method for comprehensive and accurate electrical safety distance analysis between wind turbines and overhead collector lines in current technology. For example, the paper "The Impact of the Distance between Wind Turbines and Overhead Collector Lines on the Safety and Economy of Wind Farms" uses the plane formed by the centerline of the wind turbine tower and the centerline of the iron tower as the wind turbine blade tip swept surface. By calculating the distance between the wind turbine blade tip and the top of the collector line tower, the safety verification and economic analysis of the distance between the wind turbine and the overhead collector line are performed. This method has the disadvantages of inaccurate selection of the wind turbine blade tip swept surface for verification, failure to consider wind deviation factors in extreme cases, and incorrect selection of the top of the iron tower as the minimum distance analysis point for the overhead collector line. This method is very likely to lead to incorrect verification results; for example, the invention patent "A method and research on wind farm collector line path planning" (patent number CN201711305046.4) proposes that when the wind sweeping surface of the wind turbine blade head rotates to be exactly perpendicular to the collector line path, check whether the distance between the blade tip and the overhead collector line ground wire is greater than 5m. If it is greater than 5m, the electrical safety distance between the wind turbine and the overhead collector line meets the requirements. The method mentioned in this patent has shortcomings such as overly simple step descriptions, insufficient basis for selecting a safety distance of 5m, and missing verification analysis and calculation processes, which leads to the lack of practical operability of the method. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present invention provides a method for calibrating the electrical safety distance between a wind turbine and an overhead collector line. By comprehensively considering the factors affecting the safety distance calibration, the accuracy of the calibration result is improved, allowing wind farm designers to easily and quickly make safety judgments on the layout and positioning of wind turbines and overhead collector lines.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve:

[0006] A method for verifying the electrical safety distance between a wind turbine and an overhead collector line comprises the following steps:

[0007] Step 1: Draw a wind sweep circle diagram of the fan blade tip according to the fan foundation elevation, fan hub height, blade length, and tower top deflection information;

[0008] Step 2: According to the wind turbine plan layout and the overhead collector line plan path diagram, measure the center distance between the wind turbine tower and the tower and the shortest distance between the center of the wind turbine tower and the collector line;

[0009] Step 3: By comparing the distance measured in step 2, determine the minimum free space distance between the wind turbine and the overhead collector line, draw a wind sweeping surface graph, and calculate the position of the overhead collector line on the wind sweeping surface;

[0010] Step 4: Based on the wind sweeping surface figure drawn in step 3, combined with information such as tower model and parameters, ground wire model and parameters, insulator string model and parameters, meteorological conditions, etc., draw a cross-sectional diagram of the minimum quiet distance between the wind turbine and the overhead collector line;

[0011] Step 5: According to the minimum quiet distance profile drawn in step 4, the minimum quiet distance between the wind turbine and the ground wire of the overhead collector line and the minimum quiet distance between the wind turbine and the side wire of the overhead collector line can be measured;

[0012] Step 6. Refer to the specification documents to check the minimum free space distance between the wind turbine and the ground wire of the overhead collector line and the minimum free space distance between the wind turbine and the side conductor of the overhead collector line, and determine whether the wind turbine and the overhead collector line meet the safety distance requirements.

[0013] In the preferred solution, in step 1, when drawing the swept wind circle of the wind turbine blade tip, the influence of the deflection of the top of the tower on the swept wind circle of the blade tip during the yaw of the wind turbine is considered, and the deflection of the top of the tower needs to be calculated;

[0014] In the preferred solution, in step 3, the distance between the wind turbine tower and the center of the iron tower and the shortest distance between the center of the wind turbine tower and the collector line are compared;

[0015] When the distance between the wind turbine tower and the iron tower center is greater than the shortest distance between the wind turbine tower center and the collector line: the wind sweeping surface of the wind turbine blades rotating to the path perpendicular to the collector line is the wind sweeping surface where the wind turbine blade tip has the shortest static air distance from the overhead collector line;

[0016] When the distance between the wind turbine tower and the center of the iron tower is equal to the shortest distance between the center of the wind turbine tower and the collector line: the wind sweeping surface when the wind blades rotate to the center of the iron tower is the wind sweeping surface where the quiet air distance between the wind turbine blade tip and the overhead collector line is the shortest.

[0017] In the preferred solution, in steps 4 and 5, the following two situations need to be considered when drawing the minimum clearance profile of the wind turbine and the overhead collector line:

[0018] When the center distance between the wind turbine tower and the iron tower is greater than the shortest distance between the center of the wind turbine tower and the collector line, the tower foundation elevation, the wind turbine foundation elevation, the wind turbine hub height, the tower nominal height, the vertical drop height of the conductor at the horizontal distance from the iron tower, the vertical drop height of the ground wire at the horizontal distance from the iron tower, the wind deflection angle of the conductor, the wind deflection angle of the ground wire, and the horizontal wind deflection displacement of the conductor insulator string need to be considered when drawing;

[0019] When the distance between the wind turbine tower and the center of the iron tower is greater than the shortest distance between the center of the wind turbine tower and the collector line, without considering the influence of the insulator string and the jumper, only the tower foundation elevation, the wind turbine foundation elevation, the wind turbine hub height and the tower nominal height need to be considered when drawing.

[0020] In the preferred scheme, in step 6, according to the "66kV and below overhead power line design specifications" (GB 50061-2010), when the measured minimum quiet distance between the wind turbine and the overhead collector line side conductors and both meet the requirements of Article 12.0.10 and Table 12.0.10, and the minimum quiet distance between the wind turbine and the overhead collector line ground wire is greater than the safety margin of 1 meter, it can be judged that the wind turbine and the overhead collector line meet the electrical safety distance requirements and the verification result is qualified.

[0021] This patent can achieve the following beneficial effects:

[0022] The present invention provides a method for verifying the electrical safety distance between a wind turbine and an overhead collector line, which comprehensively considers the factors affecting the safety distance verification, thereby improving the accuracy of the verification result, and the verification result can be obtained using mapping software, so that wind farm designers can easily and quickly make safety judgments on the layout and positioning of wind turbines and overhead collector lines, and is suitable for promotion and use in the field of wind farm design. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0024] Figure 1 The wind sweeping circle diagram of the fan blade tip of the present invention;

[0025] Figure 2 For the present invention 1 >L 2 The swept wind surface is when the wind turbine blade tip has the smallest quiet distance from the overhead collector line;

[0026] Figure 3 For the present invention 1 =L 2 The swept wind surface is when the wind turbine blade tip has the smallest quiet distance from the overhead collector line;

[0027] Figure 4 For the present invention 1 >L 2 Cross-sectional diagram of the minimum quiet distance between the wind turbine and the overhead collector line;

[0028] Figure 5 For the present invention 1 =L 2 Cross-sectional diagram of the minimum quiet distance between the wind turbine and the overhead collector line;

[0029] Figure 6 The wind sweeping circle diagram of the fan blade tip in the embodiment of the present invention;

[0030] Figure 7 The wind sweeping surface in the embodiment of the present invention when the wind turbine blade tip has the smallest quiet distance from the overhead collector line;

[0031] Figure 8 This is a cross-sectional view of the minimum quiet distance between the wind turbine and the overhead collector line in an embodiment of the present invention;

[0032] Fig. 9 This is a diagram for verifying the electrical safety distance between the wind turbine and the overhead collector line in an embodiment of the present invention.

[0033] In the figure: Wind turbine foundation elevation H f1 , fan hub height H f2 、Tower foundation elevation H f3 , blade length R, tower top deflection y, wind turbine hub center O, hub center after deflection O', wind turbine tower and tower center distance L 1 , the shortest distance between the center of the wind turbine tower and the collector line L 2 , the nominal height of the tower h, the vertical drop height y of the conductor at a horizontal distance L from the tower 1 , the vertical drop height y of the ground wire at the horizontal distance from the tower 2 , conductor wind deflection angle η, ground wire wind deflection angle φ, horizontal wind deflection displacement dA, wind turbine tower center O1, collector line tower center 02. DETAILED DESCRIPTION

[0034] A method for checking the electrical safety distance between a wind turbine and an overhead collector line, the specific implementation steps are as follows:

[0035] Step 1: According to the wind turbine foundation elevation H f1 , fan hub height H f2 , blade length R, tower top deflection information is drawn on the fan blade tip swept circle diagram with and without deflection (such as Figure 1 As shown in the figure, the drawing is done by using AutoCAD drawing software for equal ratio drawing and measurement. When drawing the wind sweep circle of the fan blade tip, the deflection of the top of the tower needs to be calculated y = Δy·Hf2 (Δy is the deflection limit of the tower top);

[0036] Step 2: According to the wind turbine plan layout and overhead collector line plan path diagram, measure the center distance L between the wind turbine tower and the tower. 1 The shortest distance L between the center of the wind turbine tower and the collector line 2 ;

[0037] Step 3: By comparing the distance measured in step 2, the minimum free space distance between the wind turbine and the overhead collector line is determined, and a wind sweeping surface diagram is drawn. The drawing is performed using AutoCAD drawing software for equal-ratio drawing and measurement, and the position of the overhead collector line on the wind sweeping surface is calculated;

[0038] There are two situations for the minimum quiet distance between the wind turbine and the overhead collector line:

[0039] When L 1 >L 2 When the fan blades rotate to the vertical collector line path, the swept wind surface is the swept wind surface where the fan blade tip has the smallest static air distance from the overhead collector line (e.g. Figure 2 shown);

[0040] When L 1 =L 2 When the wind sweeping surface of the fan blade rotating to the center of the tower is the wind sweeping surface where the wind blade tip has the smallest quiet distance from the overhead collector line (e.g. Figure 3 shown);

[0041] Step 4: Based on the wind sweeping surface figure drawn in step 3, combined with the tower model and parameters, ground wire model and parameters, insulator string model and parameters, meteorological conditions and other information, draw a cross-sectional diagram of the minimum quiet distance between the wind turbine and the overhead collector line (such as Figure 4 , Figure 5 As shown), the drawing is done by using AutoCAD drawing software for equal ratio drawing and measurement;

[0042] The following two situations need to be considered when drawing the minimum clearance profile of the wind turbine and the overhead collector line:

[0043] When L 1 >L 2 When drawing, the tower foundation elevation H must also be considered f3 , Wind turbine foundation elevation H f1 , fan hub height H f2 , the nominal height of the tower h, the vertical drop height y of the conductor at a horizontal distance L from the tower 1 , the vertical drop height y of the ground wire at the horizontal distance from the tower 2 ,

[0044] Conductor wind deflection angle η = arctan(γ4 / γ 1 ), ground line wind angle φ = arctan(γ 4 / γ 1 )(γ 1 is the specific load of the conductor or ground wire, γ 4 is the conductor wind load ratio),

[0045] Horizontal windage displacement of conductor insulator string (λ is the length of the tension insulator string, G H is the wind pressure on the tension insulator string, g 4 is the unit wind load, l is the span, and T is the horizontal tension of the phase conductor);

[0046] When L 1 =L 2 When the influence of insulator string and jumper is not considered, only the tower foundation elevation H needs to be considered when drawing. f3 , Wind turbine foundation elevation H f1 , fan hub height H f2 , the iron tower is called high h.

[0047] Step 5: According to the minimum clearance distance profile drawn in step 4, measure the minimum clearance distance L between the wind turbine and the overhead collector line ground wire. d The minimum clearance distance L between the wind turbine and the overhead collector line conductor b1 and L b2 ;

[0048] Step 6: According to the "66kV and below overhead power line design specifications" (GB 50061-2010), the minimum free space distance L between the wind turbine and the overhead collector line ground wire is calculated. d The minimum clearance distance L between the wind turbine and the overhead collector line conductor b1 and L b2 When the minimum quiet distance L between the wind turbine and the overhead collector line conductor is measured, b1 and L b2 All meet the requirements of Article 12.0.10 and Table 12.0.10. At the same time, the minimum quiet distance L between the wind turbine and the overhead collector line ground wire d When it is greater than the safety margin of 1 meter, it can be determined that the wind turbine and the overhead collector line meet the electrical safety distance requirements and the verification result is qualified.

[0049] Example: Take the electrical safety distance verification between the 9# wind turbine and the overhead collector line of a certain wind farm as an example:

[0050] Step 1: Draw the wind sweep circle of the fan blade tip according to the fan foundation elevation of 3029.3m, fan hub height of 85m, blade length of 65.5m, and tower top deflection information (such as Figure 6 As shown in the figure) (the deflection distance of the tower top is 0.43m, and the deflection limit of the tower top is 5 / 1000);

[0051] Step 2: According to the wind turbine plan layout and overhead collector line plan path diagram, measure the center distance L between the wind turbine tower and the tower. 1 The shortest distance L between the center of the wind turbine tower and the collector line is 39.7 m. 2 37.56m;

[0052] Step 3: By comparing the distance measured in step 2, the distance between the wind turbine tower and the center of the tower is greater than the shortest distance between the center of the wind turbine tower and the collector line (L 1 >L 2 ), so it can be determined that the swept wind surface when the fan blade rotates to the vertical collector line path is the swept wind surface when the fan blade tip has the smallest static air distance from the overhead collector line. Draw the swept wind surface when the fan blade tip has the smallest static air distance from the overhead collector line (such as Figure 7 As shown), calculate the position of the overhead collector line on the swept surface;

[0053] Step 4, according to the wind sweeping surface figure drawn in step 3, considering that the 35kV collector line tower adopts 35B6-J1 type, the conductor model is JL / G1A-120 / 25, the ground wire model is OPGW-24B1-50, the tension insulator string model is U70BP / 146, and the maximum wind speed is 33.0m / s; through measurement, it is obtained that the tower foundation elevation is 3026.9m, the tower nominal height h is 15m, the conductor is 1.26m vertically dropped at a horizontal distance L from the tower, and the ground wire is 0.89m vertically dropped at a horizontal distance from the tower;

[0054] The calculations show that the conductor windage angle is 56.6°, the ground wire windage angle is 54.2°, and the horizontal windage displacement of the conductor insulator string is 0.06m.

[0055] Draw the minimum clearance profile of the wind turbine and overhead collector line (such as Figure 8 shown);

[0056] Step 5: According to the minimum clearance distance profile drawn in step 4, the minimum clearance distance between the wind turbine and the ground wire of the overhead collector line can be measured to be 10.64m; the minimum clearance distance between the wind turbine and the side wire of the overhead collector line is 12.35m and 15.26m (such as Fig. 9 shown);

[0057] Step 6. According to Table 12.0.10 of "66kV and below overhead power line design specification" (GB 50061-2010), the minimum distance between the 35kV side conductor and the building is 3.0m. This distance is greater than the minimum free space distance between the wind turbine and the overhead collector line ground wire and the minimum free space distance between the wind turbine and the overhead collector line side conductor. Therefore, the wind turbine equipment in this example meets the electrical safety distance requirements, and the electrical safety distance between the wind farm 9# wind turbine and the overhead collector line is verified to be qualified.

[0058] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The various technical features described in the present invention can be combined with each other without conflict. The protection scope of the present invention shall be the technical solutions described in the claims, including the equivalent replacement solutions of the technical features in the technical solutions described in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for verifying the electrical safety distance between a wind turbine and an overhead collector line, characterized in that: The following steps are involved: Step 1: According to the wind turbine foundation elevation H f1 , fan hub height H f2 , blade length R, tower top deflection information to draw the wind sweep circle diagram of the fan blade tip; Step 2: According to the wind turbine plan layout and the overhead collector line plan path diagram, measure the distance L1 between the wind turbine tower and the tower center and the shortest distance L2 between the wind turbine tower center and the collector line; Step 3: By comparing the distance measured in step 2, determine the minimum free space distance between the wind turbine and the overhead collector line, draw a wind sweeping surface graph, and calculate the position of the overhead collector line on the wind sweeping surface; Step 4: Based on the wind sweeping surface figure drawn in step 3, combined with information such as tower model and parameters, ground wire model and parameters, insulator string model and parameters, meteorological conditions, etc., draw a cross-sectional diagram of the minimum quiet distance between the wind turbine and the overhead collector line; Step 5: Based on the minimum clearance distance profile drawn in step 4, the minimum clearance distance L between the wind turbine and the overhead collector line ground wire can be measured. d The minimum clearance distance L between the wind turbine and the overhead collector line conductor b1 and L b2 ; Step 6: Refer to the specification documents and calculate the minimum clearance distance L between the wind turbine and the ground wire of the overhead collector line. d The minimum clearance distance L between the wind turbine and the overhead collector line conductor b1 and L b2 Check and determine whether the wind turbine and overhead collector line meet the safety distance requirements; In step 3, the distance L1 between the wind turbine tower and the center of the iron tower and the shortest distance L2 between the center of the wind turbine tower and the collector line are compared; When L1>L2: the wind sweeping surface of the fan blades rotating to the path perpendicular to the collector line is the wind sweeping surface where the fan blade tip has the smallest static air distance from the overhead collector line; When L1=L2: the wind sweeping surface when the fan blade rotates to the center of the tower is the wind sweeping surface when the fan blade tip has the smallest quiet distance from the overhead collector line; In steps 4 and 5, the following two situations need to be considered when drawing the minimum clearance profile of the wind turbine and the overhead collector line: When L1>L2, the tower foundation elevation H needs to be considered when drawing. f3 , Wind turbine foundation elevation H f1 , fan hub height H f2 , the nominal height of the tower h, the vertical drop height y1 of the conductor at the horizontal distance L from the tower, the vertical drop height y2 of the ground wire at the horizontal distance from the tower, Conductor wind deflection angle η = arctan (γ4 / γ1), ground wire wind deflection angle φ = arctan (γ4 / γ1); γ1 is the specific load of the conductor or ground wire’s deadweight, and γ4 is the specific load of the conductor’s wind load; Horizontal windage displacement of conductor insulator string λ is the length of the tension insulator string, G H is the wind pressure on the tension insulator string, g4 is the unit wind load, l is the span, and T is the horizontal tension of the phase conductor; When L1 = L2, without considering the influence of insulator strings and jumpers, only the tower foundation elevation H needs to be considered when drawing. f3 , Wind turbine foundation elevation H f1 , fan hub height H f2 , the iron tower is called high h.

2. The method for verifying the electrical safety distance between a wind turbine and an overhead collector line according to claim 1, characterized in that: In step 1, when drawing the swept wind circle of the wind turbine blade tip, the influence of the deflection of the top of the tower on the swept wind circle of the blade tip during the yaw of the wind turbine is considered, and the deflection y of the top of the tower needs to be calculated; y=Δy·H f2 , where Δy represents the deflection limit of the tower top.

3. The method for verifying the electrical safety distance between a wind turbine and an overhead collector line according to claim 1, characterized in that: In step 6, according to the "66kV and below overhead power line design specification" GB 50061-2010, when the minimum free space distance L between the wind turbine and the overhead collector line conductor is measured b1 and L b2 All meet the requirements of Article 12.0.10 and Table 12.0.

10. At the same time, the minimum quiet distance L between the wind turbine and the overhead collector line ground wire d When it is greater than the safety margin of 1 meter, it can be determined that the wind turbine and the overhead collector line meet the electrical safety distance requirements and the verification result is qualified.

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