Construction method of overhead transmission line

Abstract

The invention discloses an overhead transmission line construction method, which relates to the technical field of electric power line construction, and comprises the following steps: step 1, optimizing a line path; the method comprises the following steps: collecting geographic information of a construction area, constructing a geographic information database, constructing an evaluation function, evaluating and calculating potential line paths, sorting according to values of the evaluation function, and selecting an optimal path; 2, according to the selected line path, in combination with factors of the voltage grade, the wire model and the transmission power of the line, site selection is carried out on the pole tower according to the heat balance principle; 3, a real-time tension monitoring system is installed, and real-time adjustment is conducted according to the needed tension value by adopting the unmanned aerial vehicle auxiliary paying-off technology; 4, foundation construction is optimized, detailed geological exploration is conducted on a construction area, parameters of soil are determined, and the pile length is calculated according to the load of a tower; and 5, constructing the overhead transmission line according to the numerical values in the steps 1-4.

Description

Technical Field

[0001] The invention relates to the technical field of power line construction, and in particular to a method for constructing an overhead power transmission line. Background Art

[0002] As a key component of the power transmission system, overhead transmission lines play an irreplaceable supporting role in the energy supply and economic development of modern society. With the acceleration of global industrialization and urbanization, the demand for electricity continues to rise, the scale of power grids continues to expand, and the construction of overhead transmission lines is becoming increasingly arduous. At the same time, it is also facing many complex challenges that need to be solved urgently.

[0003] In the traditional construction of overhead transmission lines, the selection of line paths is the first and most challenging link. This process requires consideration of many geographical factors, because the geographical environment has a profound impact on the long-term stable operation of the line. The diversity of topography, such as the ruggedness of mountainous areas, the vastness of plains, and the special conditions near water bodies, all bring difficulties to path planning. Especially in mountainous areas, towering peaks, steep valleys, and complex geological structures greatly increase the difficulty and risk of construction. Different geological conditions, such as different soil types such as rock, sand, and clay, have different characteristics such as bearing capacity, stability, and corrosiveness, which have a huge impact on the design and construction of tower foundations. Moreover, in some geologically unstable areas, such as earthquake zones or areas prone to landslides and mudslides, if the line path is not properly selected, it may suffer serious damage when natural disasters occur, thereby affecting the stability and reliability of power supply.

[0004] The positioning of the tower is also a key factor. The determination of the tower spacing needs to take into account multiple factors. First, the voltage level of the line determines the characteristics and requirements of power transmission. Different voltage levels, such as high voltage and ultra-high voltage, have different standards for electrical safety distance, electromagnetic environment, etc. The conductor model is also an important influencing factor. Different types of conductors have different electrical properties, such as resistance and current carrying capacity. Taking transmission power as an example, it is closely related to the voltage level and the maximum allowable current. While ensuring the effective transmission of power, the line resistance loss must be controlled. If the tower spacing is unreasonable, it may cause excessive line resistance loss, affect the power transmission efficiency, and may cause the conductor to bear excessive tension, thereby affecting the safety and service life of the line. In traditional construction, there are often certain limitations in the precision control of tower positioning, which may cause a series of problems in later operation, such as uneven distribution of conductor tension.

[0005] The laying process of the conductors also faces many challenges. When it is necessary to cross obstacles, traditional laying methods are often inefficient and risky. For example, when crossing a wide river or a deep valley, due to the complex terrain and environmental factors, it is difficult for traditional laying methods to accurately lay the conductors in place. In addition, meteorological conditions such as wind force and wind direction will greatly interfere with the laying process, increasing the difficulty and uncertainty of construction. At the same time, the control of conductor tension is crucial for the safe operation of the line. Under different meteorological conditions, such as temperature changes and wind speed changes, the physical properties of the conductor will change, thereby affecting its tension. If the conductor tension cannot be accurately controlled, it may cause problems such as conductor wear, broken strands, or even breakage, which seriously threatens the normal operation of the transmission line.

[0006] The foundation construction process is equally complex. Due to the diversity of geological conditions, the choice of foundation type needs to be carefully considered. In soft soil areas, such as wetlands or loose sandy areas, the foundation must have sufficient bearing capacity to support the tower and the load it bears. Different foundation types, such as pile foundations and extended foundations, have different design and construction requirements. For pile foundations, parameters such as the length and diameter of the pile need to be accurately calculated based on factors such as the bearing capacity of the soil and the load of the tower. If the foundation construction is unreasonable, the tower may tilt, sink, and other problems, which will not only affect the normal operation of the transmission line, but may also lead to serious accidents such as tower collapse.

[0007] In summary, the traditional construction method of overhead transmission lines has many areas that need to be improved in terms of path selection, tower positioning, conductor installation and foundation construction. Therefore, it is necessary to propose a new construction method for overhead transmission lines. Summary of the invention

[0008] The purpose of the present invention is to provide an overhead power transmission line construction method to solve the problems existing in the prior art of the traditional overhead power transmission line construction method in terms of path selection, tower positioning, conductor installation and foundation construction.

[0009] To achieve the above object, the present invention provides an overhead power transmission line construction method, comprising the following steps:

[0010] Step 1: Optimize the line path; collect geographic information of the construction area, build a geographic information database, construct an evaluation function F, evaluate and calculate potential line paths, sort them according to the value of the evaluation function F, and select the optimal path; the purpose of line path optimization is to select a path that is most suitable for the construction of overhead transmission lines among many potential line paths. This requires comprehensive consideration of multiple geographical factors and quantitative evaluation to avoid selecting paths that may be risky or unfavorable for construction and operation;

[0011] Step 2: According to the selected line path, combined with the line voltage level V, conductor type T and transmission power P, the tower is sited according to the thermal balance principle;

[0012] Step 3: Install a real-time tension monitoring system and use drone-assisted wire-laying technology to make real-time adjustments based on the required tension value;

[0013] Step 4: Optimize foundation construction. Conduct detailed geological surveys of the construction area, determine soil parameters, and calculate pile lengths based on the load on the tower. Foundation construction optimization is critical in the construction of overhead transmission lines. The stability of the tower foundation is directly related to the safe operation of the entire overhead transmission line. If the foundation is unstable, the tower may tilt, sink, or even collapse, leading to line failures and affecting power transmission.

[0014] Step 5: Construct the overhead transmission line according to the values ​​in steps 1 to 4.

[0015] Preferably, the specific process of optimizing the line path in step 1 is as follows:

[0016] S11. Collect detailed geographic information of the construction area, including altitude, slope, and soil type data, and build a geographic information database; these data are the basis for subsequent evaluation; for example, altitude data can reflect the height of the terrain in the area where the line passes, slope data reflects the steepness of the terrain, and soil type data is related to the difficulty and stability of foundation construction;

[0017] S12. Construct an evaluation function F, and the calculation expression is as follows:

[0018]

[0019] Where m is the number of elevation data points, l is the number of slope data points, n is the number of soil types, and p is the number of slope data points. i is the weight of the adverse impact of the i-th soil type on line construction, s i is the impact score corresponding to the i-th soil type, h j is the altitude of the jth measurement point, α kis the slope of the kth measurement section, w1, w2, and w3 are the weight coefficients of the altitude factor, the slope factor, and the soil type factor, respectively; if the value of w1 is large, it means that the influence of the altitude factor accounts for a large proportion when selecting the line path. For example, in high-altitude areas, high altitude may bring more meteorological risks (such as strong winds, low temperatures, etc.) or construction difficulties (such as altitude sickness affecting the work efficiency of construction personnel, and difficulties in transporting large equipment, etc.). At this time, a larger w1 will make it more inclined to choose a path with relatively small altitude changes or suitable altitude when evaluating the path; when w2 takes a large value, it indicates that the slope is a very critical factor in path selection. For example, in mountainous areas, a larger slope means greater construction difficulty, such as increased difficulty in earth excavation and leveling during tower foundation construction, and it may also affect the tension distribution during wire installation. Therefore, a larger w2 will prompt the selection of a path with a gentler slope; if w3 is large, it means that the influence of soil type on line construction cannot be ignored. For example, in soft soil geological areas, the soil bearing capacity is low, and special foundation design or construction methods may be required, which are costly. If w3 is large, the path selection will try to avoid areas where the soil type is not conducive to construction, and give priority to areas with good soil conditions and favorable for foundation construction.

[0020] S13. Calculate the F value for each potential path, then sort them, and select the path with the smallest F value as the optimal path.

[0021] Preferably, in step 2, according to the selected line path, combined with the factors of the line voltage level V, the conductor type T and the transmission power P, the specific process of selecting the site of the tower according to the thermal balance principle is as follows:

[0022] S21, according to the maximum allowable current I max Calculate the transmission power P, the calculation expression is as follows:

[0023] P=V×I max ;

[0024] S22, according to the principle of thermal balance, the line resistance loss P loss As constraints, determine the distance between towers and line resistance loss P loss The expression is as follows:

[0025]

[0026] Where L is the distance between towers, R T For resistance.

[0027] Preferably, the calculation expression of the tension value T in step 3 is as follows:

[0028]

[0029] Where, E is the elastic modulus, in Pascals; A w is the cross-sectional area in square meters; β is the linear expansion coefficient, t0 is the initial temperature, F is the external force on the wire, and t is the temperature in degrees Celsius.

[0030] Preferably, the process of step 4 is as follows:

[0031] S41. Use drilling and geophysical exploration methods to obtain soil samples and geological structure information at different locations in the construction area, analyze the physical and mechanical properties of soil samples, determine the soil type, and determine the bearing capacity of the soil through experiments. s Soil bearing capacity is a measure of the soil's ability to resist deformation and damage when subjected to load. Different soil types (such as clay, sand, rock, etc.) have very different bearing capacities.

[0032] S42. Calculate the load F of the tower based on the weight of the conductor, wind load, and ice load carried by the tower. t ; In order to ensure the stability of the foundation, the tower load F t Do not exceed the force that the soil can bear

[0033] S43, according to the load F of the tower t and the bearing capacity of the soil q s , calculate the pile length l p .

[0034] Preferably, in S42, the weight F of the conductor carried by the tower is 导线 , wind load F 风 , ice load F 冰 The load F of the tower t The calculation expression is as follows:

[0035] F 导线 =ρ 导线 ×L 导线 ×A 导线 ;

[0036]

[0037] F 冰 =ρ 冰 ×h 结冰厚度 ×A 结冰面积 ;

[0038] F t =F 导线 +F 风 +F 冰 ;

[0039] In the formula, ρ 导线 Indicates the material density of the conductor in kilograms per cubic meter, L 导线Indicates the length of the wire in meters, A 导线 represents the cross-sectional area of ​​the conductor in square meters, ρ 空气 Indicates the density of air in kilograms per cubic meter, V 风速 Indicates wind speed in meters per second, C 风阻系数 Indicates the wind resistance coefficient of the tower or conductor, A 迎风面积 It represents the windward area of ​​the tower or conductor in square meters. 冰 Indicates the density of ice in kilograms per cubic meter, h 结冰厚度 Indicates the thickness of ice in meters, A 结冰面积 It indicates the ice area of ​​the pole tower or conductor, in square meters.

[0040] Preferably, in S43, according to the load F of the tower t and the bearing capacity of the soil q s , pile length l p The calculation expression is as follows:

[0041]

[0042] In the formula, l p is the pile length in meters; F t is the tower load, in kN; q s is the bearing capacity of the soil, in kPa; A is the cross-sectional area of ​​the pile, in square meters.

[0043] Therefore, the present invention adopts the above-mentioned overhead transmission line construction method, which has the following beneficial effects:

[0044] (1) Improved line safety. By avoiding geological disaster risk areas, the possibility of line damage due to natural disasters is reduced. At the same time, the construction cost is reduced. By choosing a better path, the number of towers and the length of conductors can be reduced, thereby saving material and construction costs.

[0045] (2) Improved the stability of the transmission line. Accurate tower positioning can ensure a reasonable spacing between towers, making the tension distribution of the conductor more uniform and facilitating subsequent maintenance and inspection;

[0046] (3) Ensure the safe operation of the conductor under different meteorological conditions. Real-time tension monitoring and adjustment can prevent the conductor from being damaged due to excessive or insufficient tension;

[0047] (4) The stability of the tower foundation is ensured. The foundation size is accurately calculated according to the geological conditions and tower load, which can effectively prevent the tower from tilting or collapsing.

[0048] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The present invention is an overall flow chart of an overhead power transmission line construction method. DETAILED DESCRIPTION

[0050] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] See also Figure 1 , an overhead transmission line construction method, comprising the following steps:

[0052] Step 1: Optimize the line path; collect geographic information of the construction area, build a geographic information database, construct an evaluation function F, evaluate and calculate potential line paths, sort them according to the value of the evaluation function F, and select the optimal path; the purpose of line path optimization is to select a path that is most suitable for the construction of overhead transmission lines among many potential line paths. This requires comprehensive consideration of multiple geographical factors and quantitative evaluation to avoid selecting paths that may be risky or unfavorable for construction and operation; the specific process of optimizing line paths is as follows:

[0053] S11. Collect detailed geographic information of the construction area, including altitude, slope, and soil type data, and build a geographic information database; these data are the basis for subsequent evaluation; for example, altitude data can reflect the height of the terrain in the area where the line passes, slope data reflects the steepness of the terrain, and soil type data is related to the difficulty and stability of foundation construction;

[0054] S12. Construct an evaluation function F, and the calculation expression is as follows:

[0055]

[0056] Where m is the number of elevation data points, l is the number of slope data points, n is the number of soil types, and p is the number of slope data points. i is the weight of the adverse impact of the i-th soil type on line construction, s i is the impact score corresponding to the i-th soil type, h j is the altitude of the jth measurement point, α kis the slope of the kth measurement section, w1, w2, and w3 are the weight coefficients of the altitude factor, the slope factor, and the soil type factor, respectively; if the value of w1 is large, it means that the influence of the altitude factor accounts for a large proportion when selecting the line path. For example, in high-altitude areas, high altitude may bring more meteorological risks (such as strong winds, low temperatures, etc.) or construction difficulties (such as altitude sickness affecting the work efficiency of construction personnel, and difficulties in transporting large equipment, etc.). At this time, a larger w1 will make it more inclined to choose a path with relatively small altitude changes or suitable altitude when evaluating the path; when w2 takes a large value, it indicates that the slope is a very critical factor in path selection. For example, in mountainous areas, a larger slope means greater construction difficulty, such as increased difficulty in earth excavation and leveling during tower foundation construction, and it may also affect the tension distribution during wire installation. Therefore, a larger w2 will prompt the selection of a path with a gentler slope; if w3 is large, it means that the influence of soil type on line construction cannot be ignored. For example, in soft soil geological areas, the soil bearing capacity is low, and special foundation design or construction methods may be required, which are costly. If w3 is large, the path selection will try to avoid areas where the soil type is not conducive to construction, and give priority to areas with good soil conditions and favorable for foundation construction.

[0057] S13. Calculate the F value for each potential path, then sort them, and select the path with the smallest F value as the optimal path.

[0058] Step 2: According to the selected line path, combined with the line voltage level V, conductor type T and transmission power P, the tower is sited according to the thermal balance principle; the specific process is as follows:

[0059] S21, according to the maximum allowable current I max Calculate the transmission power P, the calculation expression is as follows:

[0060] P=V×I max ;

[0061] S22, according to the principle of thermal balance, the line resistance loss P loss As constraints, determine the distance between towers and line resistance loss P loss The expression is as follows:

[0062]

[0063] Where L is the distance between towers, R T For resistance.

[0064] Step 3: Install a real-time tension monitoring system and use drone-assisted wire-laying technology to make real-time adjustments based on the required tension value; the calculation expression of the tension value T is as follows:

[0065]

[0066] Where, E is the elastic modulus, in Pascals; A w is the cross-sectional area in square meters; β is the linear expansion coefficient, t0 is the initial temperature, F is the external force on the wire, and t is the temperature in degrees Celsius.

[0067] Step 4: Optimize foundation construction. Conduct detailed geological surveys of the construction area, determine soil parameters, and calculate pile lengths based on the load of the tower. Foundation construction optimization is critical in the construction of overhead transmission lines. The stability of the tower foundation is directly related to the safe operation of the entire overhead transmission line. If the foundation is unstable, the tower may tilt, sink, or even collapse, leading to line failures and affecting power transmission. The specific process is as follows:

[0068] S41. Use drilling and geophysical exploration methods to obtain soil samples and geological structure information at different locations in the construction area, analyze the physical and mechanical properties of soil samples, determine the soil type, and determine the bearing capacity of the soil through experiments. s Soil bearing capacity is a measure of the soil's ability to resist deformation and damage when subjected to load. Different soil types (such as clay, sand, rock, etc.) have very different bearing capacities.

[0069] S42. Calculate the load F of the tower based on the weight of the conductor, wind load, and ice load carried by the tower. t ; In order to ensure the stability of the foundation, the tower load F t The force cannot exceed the soil's bearing capacity; according to the conductor weight F carried by the tower 导线 , wind load F 风 , ice load F 冰 The load F of the tower t The calculation expression is as follows:

[0070] F 导线 =ρ 导线 ×L 导线 ×A 导线 ;

[0071]

[0072] F 冰 =ρ 冰 ×h 结冰厚度 ×A 结冰面积 ;

[0073] F t =F 导线 +F 风 +F 冰 ;

[0074] In the formula, ρ导线 Indicates the material density of the conductor in kilograms per cubic meter, L 导线 Indicates the length of the wire in meters, A 导线 represents the cross-sectional area of ​​the conductor in square meters, ρ 空气 Indicates the density of air in kilograms per cubic meter, V 风速 Indicates wind speed in meters per second, C 风阻系数 Indicates the wind resistance coefficient of the tower or conductor, A 迎风面积 It represents the windward area of ​​the tower or conductor in square meters. 冰 Indicates the density of ice in kilograms per cubic meter, h 结冰厚度 Indicates the thickness of ice in meters, A 结冰面积 It indicates the ice area of ​​the pole tower or conductor, in square meters.

[0075] S43, according to the load F of the tower t and the bearing capacity of the soil q s , calculate the pile length l p ; The specific expression is as follows:

[0076]

[0077] In the formula, l p is the pile length in meters; F t is the tower load, in kN; q s is the bearing capacity of the soil, in kPa; A is the cross-sectional area of ​​the pile, in square meters.

[0078] Step 5: Construct the overhead transmission line according to the values ​​in steps 1 to 4.

[0079] Therefore, the present invention adopts the above-mentioned overhead transmission line construction method to reduce construction costs and improve the stability of the transmission line by optimizing the line path, accurately selecting and positioning the pole towers, and installing a real-time tension monitoring system.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for constructing an overhead power transmission line, characterized in that: The following steps are involved: Step 1: Optimize the route. Collect geographic information of the construction area, build a geographic information database, construct an evaluation function F, evaluate and calculate potential route paths, sort them according to the value of the evaluation function F, and select the optimal path. Step 2: According to the selected line path, combined with the line voltage level V, conductor type T and transmission power P, the tower is sited according to the thermal balance principle; Step 3: Install a real-time tension monitoring system and use drone-assisted wire-laying technology to make real-time adjustments based on the required tension value; Step 4: Optimize foundation construction by conducting detailed geological surveys of the construction area, determining soil parameters, and calculating pile lengths based on tower loads; Step 5: Construct the overhead transmission line according to the values ​​in steps 1 to 4.

2. An overhead power transmission line construction method according to claim 1, characterized in that: The specific process of optimizing the line path in step 1 is as follows: S11. Collect detailed geographic information of the construction area, including altitude, slope, and soil type data, and build a geographic information database; S12. Construct an evaluation function F, and the calculation expression is as follows: Where m is the number of elevation data points, l is the number of slope data points, n is the number of soil types, and p is the number of slope data points. i is the weight of the adverse impact of the i-th soil type on line construction, s i is the impact score corresponding to the i-th soil type, h j is the altitude of the jth measurement point, α k is the slope of the kth measurement section, w1, w2, and w3 are the weight coefficients of altitude factor, slope factor, and soil type factor, respectively; S13. Calculate the F value for each potential path, then sort them, and select the path with the smallest F value as the optimal path.

3. An overhead power transmission line construction method according to claim 2, characterized in that: In step 2, according to the selected line path, combined with the line voltage level V, conductor type T and transmission power P, the specific process of selecting the site for the tower according to the thermal balance principle is as follows: S21, according to the maximum allowable current I max Calculate the transmission power P, the calculation expression is as follows: P=V×I max ; S22, according to the principle of thermal balance, the line resistance loss P loss As constraints, determine the distance between towers and line resistance loss P loss The expression is as follows: Where L is the distance between towers, R T For resistance.

4. An overhead power transmission line construction method according to claim 3, characterized in that: The calculation expression of the tension value T in step 3 is as follows: Where, E is the elastic modulus, in Pascals; A w is the cross-sectional area in square meters; β is the linear expansion coefficient, t0 is the initial temperature, F is the external force on the wire, and t is the temperature in degrees Celsius.

5. An overhead power transmission line construction method according to claim 4, characterized in that: The process for step 4 is as follows: S41. Use drilling and geophysical exploration methods to obtain soil samples and geological structure information at different locations in the construction area, analyze the physical and mechanical properties of soil samples, determine the soil type, and determine the bearing capacity of the soil through experiments. s ; S42. Calculate the load F of the tower based on the weight of the conductor, wind load, and ice load carried by the tower. t ; S43, according to the load F of the tower t and the bearing capacity of the soil q s , calculate the pile length l p .

6. An overhead power transmission line construction method according to claim 5, characterized in that: In S42, the weight of the conductor carried by the tower is F 导线 , wind load F 风 , ice load F 冰 The load F of the tower t The calculation expression is as follows: F 导线 =ρ 导线 ×L 导线 ×A 导线 ; F 冰 =ρ 冰 ×h 结冰厚度 ×A 结冰面积 ; F t =F 导线 +F 风 +F 冰 ; In the formula, ρ 导线 Indicates the material density of the conductor in kilograms per cubic meter, L 导线 Indicates the length of the wire in meters, A 导线 represents the cross-sectional area of ​​the conductor in square meters, ρ 空气 Indicates the density of air in kilograms per cubic meter, V 风速 Indicates wind speed in meters per second, C 风阻系数 Indicates the wind resistance coefficient of the tower or conductor, A 迎风面积 It represents the windward area of ​​the tower or conductor in square meters. 冰 Indicates the density of ice in kilograms per cubic meter, h 结冰厚度 Indicates the thickness of ice in meters, A 结冰面积 It indicates the ice area of ​​the pole tower or conductor, in square meters.

7. An overhead power transmission line construction method according to claim 6, characterized in that: According to the load F of the tower in S43 t and the bearing capacity of the soil q s , pile length l p The calculation expression is as follows: In the formula, l p is the pile length in meters; F t is the tower load, in kN; q s is the bearing capacity of the soil, in kPa; A is the cross-sectional area of ​​the pile, in square meters.

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