Device and method for detecting sag and cable force of inhaul cable of flexible photovoltaic support

Abstract

The invention provides a flexible photovoltaic support inhaul cable sag and cable force detection device and method, and relates to the photovoltaic technical field, and the method comprises the steps: measuring the sag of a flexible photovoltaic support inhaul cable, combining the technical parameters of a flexible photovoltaic support, and constructing an inhaul cable calculation equation through a mechanical modeling method to solve the cable force of the inhaul cable; the device comprises a measuring part and a positioning part, the measuring part comprises a first vertical rod, the top end of the first vertical rod is provided with a laser range finder, the laser range finder is rotationally connected with the first vertical rod, one side of the laser range finder is provided with an angle measuring semicircular ruler, the side, away from the laser range finder, of the angle measuring semicircular ruler is provided with a first positioning ruler, and the first vertical rod is further provided with a bubble level gauge; the positioning part comprises a second vertical rod, a light reflecting plate is arranged at the top end of the second vertical rod, a laser positioning ring is arranged in the center of the light reflecting plate, a laser sight bead ring is concentrically arranged in the laser positioning ring, a second positioning scale is arranged on one side of the light reflecting plate, and a bubble level is arranged on the second vertical rod. The device has the characteristic of simple measurement operation.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a device and method for detecting sag and cable force of a flexible photovoltaic support cable. Background Art

[0002] Under the background of the dual carbon goals, the photovoltaic industry has developed rapidly. With the expansion of photovoltaic installed capacity, some mountains, deserts, plains and fish ponds with better conditions have been gradually developed, and the available land resources are decreasing. Flexible photovoltaic brackets can achieve an important technical direction of reducing land use conflicts by tensioning prestressed steel strands between two supports and fixing photovoltaic panels on the steel strands by buckles. As a new type of photovoltaic bracket, flexible photovoltaic brackets have obvious technical advantages and have begun to be widely used in photovoltaic projects in recent years. However, in actual engineering, there is a lack of equipment and facilities for construction quality detection methods and project quality acceptance of flexible photovoltaic brackets.

[0003] Flexible photovoltaic support is a kind of cable structure photovoltaic support that applies large prestress to the flexible cable of steel strand to greatly improve the stiffness of the steel strand cable, so that it has the ability to bear the deadweight of photovoltaic modules and wind load. The size of the prestress applied by the cable directly determines the stiffness and bearing capacity of the cable, which in turn affects the safety of the structure and the construction quality of the project; the sag of the steel strand under the action of prestress and the gravity of the bearing assembly will cause the orientation of the photovoltaic module to change, resulting in a decrease in the power generation efficiency of the module, so the cable sag needs to be controlled in actual engineering. However, in actual engineering construction, the prestress of the cable of the continuous multi-span flexible photovoltaic support structure is generally applied by a through-hole jack at the two ends of the steel strand cable, and the value of the prestress is read by the oil pressure gauge of the jack; however, due to the friction loss of the steel strand at the middle column, there is often a certain difference in the prestress value applied to each span of the multi-span continuous cable; on the other hand, it is subject to the influence of the technical level and sense of responsibility of the construction personnel, and it is difficult to avoid the problem of insufficient prestress of some cables when tensioning a large number of cables. After the photovoltaic project is completed, during the long-term operation of the flexible photovoltaic support structure, the steel strand cables may become loose due to earthquakes, snowstorms or other sudden disasters. It is also necessary to measure the tension and sag of the steel strand cables to evaluate the safety of the structure.

[0004] Therefore, the flexible photovoltaic bracket project urgently needs a cable tension and sag measurement tool to test the tension and sag of the steel strands after tensioning during installation or after relaxation due to disasters, so as to verify whether the tensioning cable force and cable sag of the flexible photovoltaic bracket meet the design requirements, and provide measured data for project acceptance and safety evaluation after the project is affected by disasters, so as to ensure the quality and safety of the project.

[0005] The traditional pressure sensor technology for measuring cable tension is relatively mature, but it needs to be connected in series with the cable and needs to be pre-buried before the cable is installed and tensioned, which is not suitable for quality inspection of engineering projects. After searching, no detection device and method for cable tension and sag applied to flexible photovoltaic brackets have been found. Invention patent A frequency method cable tension measurement method based on frequency optimization (CN117647347B) relies on the vibration frequency of the cable to measure the cable tension, which is suitable for the cable tension measurement of empty cables with no load between cable spans, but this type of technology cannot be applied to cables with full photovoltaic module loads between flexible photovoltaic brackets. Inventions such as a non-destructive in-situ measurement device and method (CN109596257B) rely on the magnetic flux principle to measure cable tension, but the closed-loop magnetic flux cable tension meter requires the sensor to be pre-inserted before the cable is tensioned, and it cannot be disassembled after installation, which is not suitable for engineering inspection; the open-loop magnetic flux cable tension meter has magnetic leakage, and the measurement result has a large error, which is also not suitable for engineering applications. The present invention measures the shape of the cable and calculates the cable force based on the principle of mechanics. The detection tool used is a portable device that does not need to be installed or disassembled on the structure, thereby solving the problem of convenient measurement and spot inspection of cable force and sag measurement of flexible photovoltaic brackets. Summary of the invention

[0006] The present invention provides a flexible photovoltaic support cable sag and cable force detection device and method, aiming to solve at least one technical problem existing in the prior art mentioned in the background technology.

[0007] The present invention provides the following technical solutions to achieve the above objectives:

[0008] A device for detecting the sag and cable force of a flexible photovoltaic support cable comprises a measuring part and a positioning part. The measuring part comprises a first vertical pole, a distance measuring machine head is arranged at the top of the first vertical pole, the distance measuring machine head comprises a motor, a laser distance meter is arranged on the rotating shaft of the motor, an angle measuring semicircular ruler is arranged on one side of the laser distance meter, the circle center of the angle measuring semicircular ruler is arranged corresponding to the rotating shaft, a positioning scale one is arranged on the side of the angle measuring semicircular ruler away from the laser distance meter, and a bubble level is also arranged on the first vertical pole; the positioning part comprises a second vertical pole, a reflector is arranged at the top of the second vertical pole, a laser positioning circle is arranged at the center of the reflector, a laser sight circle is concentrically arranged in the laser positioning circle, a positioning scale two is arranged on one side of the reflector, and a bubble level is arranged on the second vertical pole; the laser distance between the first positioning scale and the laser distance meter is equal to the distance between the second positioning scale and the laser sight circle.

[0009] Furthermore, the vertical pole 1 and the vertical pole 2 are telescopic poles, and the pole bodies are provided with scales. The vertical pole 1 and the vertical pole 2 include a lower pipe rod member, the lower pipe rod member is sleeved with an upper pipe rod member, and the lower pipe rod member is provided with fastening bolts.

[0010] Furthermore, a telescope is arranged on the first vertical pole.

[0011] Furthermore, a controller is provided on the first vertical pole, and the controller is electrically connected to the laser rangefinder and the motor; the controller is installed on the fuselage support, and the fuselage support is connected to the first vertical pole through a spring clip, and a calculation program is preset in the controller.

[0012] Furthermore, one end of the reflector connected to the second vertical pole is provided with a reflector stiffening thick edge, the middle of the reflector stiffening thick edge is provided with a connecting bolt hole, and the reflector stiffening thick edge is connected to the second vertical pole through the connecting bolt hole.

[0013] Furthermore, a rubber gasket is provided on the contact surface between the spring clip and the second vertical pole.

[0014] Furthermore, the method for detecting the sag and cable force of the flexible photovoltaic support cable comprises measuring the sag of the flexible photovoltaic support cable, combining the technical parameters of the flexible photovoltaic support and solving the cable force of the cable by constructing a cable calculation equation through a mechanical modeling method;

[0015] The method for measuring sag includes connecting two end points of the flexible photovoltaic support to form a straight line, keeping the angle of the straight line unchanged, adjusting the height of the straight line to be tangent to the bottom of the cable, the point where the straight line is tangent to the cable is the sag position, and the adjusted height of the straight line is the sag;

[0016] The process of establishing the cable calculation equation includes:

[0017] Based on the self-gravity of the cable, considering that the photovoltaic panels are evenly spaced on the cable, the self-gravity of the cable and the weight of the photovoltaic panel are equivalent to a uniform linear load through the principle of mechanical calculation, and the equation is established as follows:

[0018] Where f is the sag, F is the cable force, L1 is the chord length of the cable, α is the angle between L1 and the horizontal plane, and q is the uniform linear load.

[0019] Furthermore, the technical parameters include cable length, specifications, photovoltaic panel model and number of photovoltaic panels.

[0020] Beneficial Effects

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses the principle of laser ranging to set up measuring components and positioning parts at both ends of a span of the flexible photovoltaic support cable to measure the cable chord length and inclination angle, convert the cable sag through geometric principles, and convert the cable force through mechanical principles.

[0023] The present invention provides a flexible photovoltaic support cable sag and cable force detection device and method, which provides a measurement means and method for project quality inspection and post-disaster quality evaluation of the project;

[0024] The present invention can measure the cable force without the need for the sensor to be embedded in the cable itself in advance, without the need for pre-installation process, without the need to be installed on the structure itself, and the detection operation has no impact on the structure;

[0025] The present invention uses optical principles and mechanical principles for detection, does not use precision sensors and precision electronic instruments, the detection results are not affected by the external environment, and the error of the detection results is small;

[0026] The device of the present invention is all small components, which are convenient to carry, install and disassemble, and the measurement operation is simple and convenient to operate. It is suitable for various complex landforms and application scenarios such as mountains, fish ponds, and building photovoltaics;

[0027] The present invention provides a method for obtaining the cable force and sag by carrying out detection work at the columns at both ends of the structure, without setting up detection instruments at the mid-span position of the structure. The method is suitable for photovoltaic power stations in complex terrain scenarios such as across gullies and deep-water fish ponds, where the mid-span position of flexible photovoltaic brackets is difficult for ground detection personnel to reach and it is inconvenient to set up a measurement and positioning unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below only relate to some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

[0029] Figure 1 It is a schematic diagram of the structure of the measuring part of the present invention;

[0030] Figure 2 It is a schematic diagram of the positioning part structure of the present invention;

[0031] Figure 3 This is a schematic diagram of the distance measuring head structure of the present invention;

[0032] Figure 4 for Figure 3 AA section view;

[0033] Figure 5 It is a schematic diagram of the fuselage support and spring clip structure;

[0034] Figure 6 It is a schematic diagram of the controller of the present invention;

[0035] Figure 7 It is a schematic diagram of the structure of the reflector of the present invention;

[0036] Figure 8 for Figure 7BB section view;

[0037] Fig. 9 A schematic diagram of a method for using the present invention;

[0038] Fig.10 This is a schematic diagram of the second method of using the present invention;

[0039] Fig.11 This is a calculation principle diagram of the first method of the present invention;

[0040] Fig.12 This is the calculation principle diagram of method 2 used in the present invention.

[0041] Figure markings: 1-rangefinder head; 1.1-laser rangefinder; 1.2-laser; 1.3-angle measuring semicircular ruler; 1.4-motor; 1.5-rotating shaft; 1.6-bolt hole; 1.7-positioning scale one; 2-upright pole; 2.1-upright pole one; 2.2-upright pole two; 3-controller; 3.1 controller display; 3.2-control buttons; 3.3-parameter buttons; 3.4-fuselage support; 3.5-spring clip; 3.6-rubber gasket; 4-bubble level; 5-telescope; 6-reflector; 6.1-laser positioning ring; 6.2-laser sight ring; 6.3-positioning scale two; 6.4-reflector stiffening thick edge; 6.5-connecting bolt hole; 7-cable; 8-anchoring inclined cable; 9-support column. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0043] It should be noted that in the present invention: the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or apparatuses; the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like are based on the directions or positional relationships shown in the drawings. These The terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation; the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence; the terms "install", "set", "provided with", "connected", "connected", "sleeved", etc. should be understood in a broad sense; for example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. In addition, some terms can be used to express other meanings in addition to indicating orientation or positional relationships. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0044] Embodiment 1. A device for detecting the sag and cable force of a flexible photovoltaic support cable, the structure of which is referenced Figure 1, including a measuring part and a positioning part, the measuring part includes a vertical pole 2.1, a distance measuring machine head 1 is arranged at the top of the vertical pole 2.1, the distance measuring machine head 1 includes a motor 1.4, a laser distance meter 1.1 is arranged on the rotating shaft 1.5 of the motor 1.4, an angle measuring semicircular ruler 1.3 is arranged on one side of the laser distance meter 1.1, the center of the angle measuring semicircular ruler 1.3 is arranged corresponding to the rotating shaft 1.5, a positioning ruler 6.3 is arranged on the side of the angle measuring semicircular ruler 1.3 away from the laser distance meter 1.1, and a vertical pole 2.1 is also provided with A bubble level 4 is arranged; the positioning part comprises a second vertical pole 2.2, a reflector 6 is arranged at the top of the second vertical pole 2.2, a laser positioning circle 6.1 is arranged at the center of the reflector 6, a laser sight circle 6.2 is arranged concentrically in the laser positioning circle 6.1, a positioning ruler 2 6.3 is arranged on one side of the reflector 6, and the bubble level 4 is arranged on the second vertical pole 2.2; the distance between the positioning ruler 1 6.3 and the laser 1.2 of the laser rangefinder 1.1 is equal to the distance between the positioning ruler 2 6.3 and the laser sight circle 6.2. The positioning scale 1 6.3 and the positioning scale 2 6.3 are pointer-type structures for easy precise positioning; a laser positioning circle 6.1 is provided at the center of the reflector 6 to ensure the accuracy of the laser rangefinder 1.1 during the measurement process; and the laser distance between the positioning scale 1 6.3 and the laser rangefinder 1.1 is set equal to the distance between the positioning scale 2 6.3 and the laser sight circle 6.2 to ensure that the rangefinder laser 1.2 falls within the sight circle of the reflector 6.

[0045] The vertical pole 1 2.1 and the vertical pole 2.2 are telescopic poles, and a scale is arranged on the pole body. The vertical pole 1 2.1 and the vertical pole 2.2 include a lower pipe rod, and the lower pipe rod is sleeved with an upper pipe rod, and a fastening bolt is arranged on the lower pipe rod. The telescopic movement of the vertical pole 1 2.1 and the vertical pole 2 2.2 is achieved by sleeve-connecting the lower pipe rod and the upper pipe rod, and the fixation of the vertical pole 1 2.1 and the vertical pole 2 2.2 is achieved by fastening bolts; the scale is arranged on the vertical pole 1 2.1 and the vertical pole 2 2.2 to facilitate the direct reading of the height of the laser rangefinder 1.1 during the measurement process.

[0046] The vertical pole 2.1 is provided with a telescope 5. The telescope 5 facilitates observation from the measuring part to the positioning part during the measurement process, ensuring that the laser 1.2 of the laser rangefinder 1.1 falls into the laser positioning circle 6.1 of the reflector 6, thereby ensuring the accuracy of the measurement effect.

[0047] The end of the reflector 6 connected to the second upright pole 2.2 is provided with a reflector stiffening thick edge 6.4, and a connecting bolt hole 6.5 is provided in the middle of the reflector stiffening thick edge 6.4. The reflector stiffening thick edge 6.4 is connected to the second upright pole 2.2 through the connecting bolt hole 6.5. The reflector stiffening thick edge 6.4 is provided on the reflector 6 to improve the connection strength between the reflector 6 and the second upright pole 2.2, thereby ensuring the safety of the positioning part.

[0048] Embodiment 2, the structure of this embodiment is the same as that of embodiment 1, the only difference being that a controller 3 is provided on the vertical pole 1 2.1, the controller 3 is electrically connected to the laser rangefinder 1.1 and the motor 1.4; the controller 3 is mounted on a fuselage support 3.4, the fuselage support 3.4 is connected to the vertical pole 1 2.1 through a spring clip 3.5, and a calculation program is provided in the controller 3. A rubber gasket 3.6 is provided on the contact surface between the spring clip 3.5 and the vertical pole 2.2. The calculation procedure includes: presetting the cross-sectional area of ​​the cable steel strand diameter and the regular weight of the commonly used photovoltaic components in the manipulator 3, according to the mechanical calculation principle, the gravity of the cable itself and the laying of the photovoltaic panel are regarded as the uniform linear load and recorded as q, based on the installation situation, specifications and selected cable steel strand specifications of the photovoltaic panels at the project site, the uniform linear load calculation equation is established and q is solved, and the solved q is substituted into the cable force equation to solve the cable force F; when measuring, only the cable and photovoltaic component specifications are selected, and there is no need to input the cross-sectional area and component weight to establish the uniform linear load q of the cable steel strand specifications, so as to simplify the measurement procedure; and the manipulator 3 is prevented from sliding by setting a rubber gasket 3.6 on the contact surface between the spring clip 3.5 and the vertical pole 2.2.

[0049] The method of use of the present invention is as follows:

[0050] Method of use 1: When the flexible photovoltaic support is installed in an area accessible to humans, the flexible photovoltaic support includes a cable 7, both ends of which are installed on the top of a support column 9, and an anchoring inclined cable 8 is provided on the side of the support column 9 away from the cable 7;

[0051] 1) Install the measuring components

[0052] During the measurement operation, assemble the measuring components on the ground and place them on one end of the cable 7. Raise the vertical pole 2.1 so that the distance measuring machine head positioning scale 1.7 reaches the height of the end of the load-bearing cable 7, and the arrow of the positioning scale 1.7 is close to the center of the side of the load-bearing cable 7, and fix the fastening bolts;

[0053] 2) Install the positioning part

[0054] During the measurement operation, assemble the positioning part on the ground and place it on the other end of the load-bearing cable 7. Raise the second pole 2.2 so that the reflector positioning scale 6.3 reaches the height of the end of the load-bearing cable 7, and the arrow of the positioning scale is close to the center of the side of the load-bearing cable 7, and fix the fastening bolts. Adjust the bubble of the bubble level 4 on the second pole 2.2 to the center to ensure that the second pole 2.2 is vertical;

[0055] 3) Debugging and measuring components

[0056] Search the position of the reflector through the telescope 5, and turn the adjustment pole 1 2.1 to ensure that the telescope's field of view can fall within the laser positioning circle 6.1 of the reflector 6. Adjust the bubble of the bubble level 4 on the pole 1 2.1 to the center to ensure that the pole 1 2.1 is vertical;

[0057] 4) Measure the chord length L1 between cable spans

[0058] Turn on the laser rangefinder laser 1.2 through the controller 3, use the telescope 5 to observe the reflector, adjust the laser rangefinder emission angle of the laser 1.2 through the control button 3.2 of the controller 3, so that the laser 1.2 falls within the crosshair circle 6.2 of the reflector, click the keyboard button 3.3 of the controller 3 to trigger the measurement, measure the cable chord length L1, and read the laser 1.2 emission angle α from the angle measuring semicircular ruler 1.3;

[0059] 5) Search for the mid-span position of the cable

[0060] Keep the position of the measuring part unchanged, the emission angle α of the laser 1.2 unchanged, move the reflective part to the mid-span position, reinstall the positioning part and adjust the vertical pole 2.2 until the laser 1.2 falls on the reflector positioning circle 6.1, click the keyboard button 3.3 of the controller 3 again to trigger the measurement, and measure the distance L2. Adjust the position of the measuring component several times so that the measured L2 is in the following range, and the positioning part position at this time is considered to be the mid-span position of the cable. L2 in the following range can ensure that the measurement result error is ±1%, which meets the general project inspection requirements;

[0061]

[0062] 6) Measure the chord length L3 from the cable end to the cable mid-span position

[0063] Keep the position of the positioning part pole 2.2 unchanged, lower the height of the pole 2.2, align the positioning ruler 2.6.3 with the position of the cable body in the middle of the span of the load-bearing cable, and the arrow of the positioning ruler 2.6.3 is close to the center of the side of the middle of the span of the load-bearing cable 7, and fix the fastening bolts. Use the control button 3.2 of the controller 3 to adjust the laser emission angle of the laser rangefinder so that the laser point falls within the laser sight circle 6.2, click the keyboard button 3.3 of the controller 3 to trigger the measurement, measure the chord length L3 from the end of the cable to the middle of the span of the cable, and read the laser emission angle β from the angle measuring semicircular ruler 1.3;

[0064] 7) Input cable load

[0065] Input the cable load parameters by pressing key 3.3 on keyboard 3 of controller 3, including the cable cross-sectional area A, the deadweight G of a single photovoltaic panel, the number N of photovoltaic panels arranged in one span, and the number m of cables directly supporting the assembly;

[0066] 8) Output sag and cable force test results

[0067] A calculation program is set in the manipulator 3. According to the input load parameters and the measured data, the cable force and sag are calculated and displayed on the manipulator display screen 3.1. The calculation program is as follows:

[0068]

[0069] Method of use 2: When the flexible photovoltaic bracket is set up in an area that is inaccessible to humans, such as rivers, cliffs, and gullies, and when the height difference between the two ends of the flexible photovoltaic bracket is too large (the height difference is greater than 10% of the bracket height), the sag of the flexible photovoltaic bracket does not occur in the mid-span position.

[0070] 1) Install the measuring components

[0071] During the measurement operation, the measuring components are assembled on the ground and placed at one end of the load-bearing cable 7. Raise the vertical pole 2.1 so that the distance measuring head positioning scale 1.7 reaches the height of the end of the load-bearing cable 7, the positioning scale arrow is close to the center of the side of the load-bearing cable 7, and the fastening bolts are fixed.

[0072] 2) Install the positioning part

[0073] During the measurement operation, assemble the reflective part on the ground and place it on the other end of the load-bearing cable 7. Raise the vertical pole 2.2 so that the reflective plate positioning scale 2.3 reaches the height of the end of the load-bearing cable 7, and the arrow of the positioning scale 2.3 is close to the center of the side of the load-bearing cable 7, and the fastening bolts are fixed. Adjust the bubble of the bubble level 4 of the vertical pole 2.2 to the center to ensure that the vertical pole 2.2 is vertical.

[0074] 3) Debugging and measuring components

[0075] Search the position of the reflector 6 through the telescope 5, adjust the position of the pole 2.1, and ensure that the sight of the telescope 5 can fall within the laser positioning circle 6.1. Adjust the bubble of the bubble level 4 on the pole 2.1 to the center to ensure that the pole 2.1 is vertical.

[0076] 4) Read the height h1 of the laser instrument of the measuring part through the scale of the pole-2.1 shaft

[0077] 5) Measure the cable span chord length L1

[0078] Turn on the laser rangefinder laser 1.2 through the controller 3, use the telescope 5 to observe the reflector, adjust the angle of the laser rangefinder 1.1 to emit the laser 1.2 through the control button 3.2 of the controller 3, so that the laser 1.2 falls within the crosshair circle 6.2 of the reflector, click the keyboard button 3.3 of the controller 3 to trigger the measurement, and measure the cable chord length L1 and the laser emission angle α.

[0079] 6) Move, reinstall and debug measuring components

[0080] Keep the emission angle α of the laser 1.2 of the laser rangefinder 1.1 of the measuring part unchanged, move the measuring component so that the laser rangefinder 1.1 is directly below the end of one end of the cable, reinstall the measuring part, and adjust the handheld pole 2.1 to the lowest position; turn to adjust the position of the pole 2.1 to ensure that the sight of the telescope 5 field of view can fall on the cable body, adjust the bubble of the bubble level 4 on the pole 2.1 to the center, and ensure that the handheld telescopic pole 2.1 is vertical.

[0081] 7) Search for the cable sag position and read the laser height h2 of the measuring component

[0082] Keep the laser emission angle α unchanged, slowly adjust and raise the vertical pole 2.1, use the telescope 5 to observe the laser point, when half of the laser dot just falls on the lower end of the cable body (the laser 1.2 is tangent to the cable body), fix the vertical pole 2.1, and read the height h2 of the laser instrument of the measuring component through the scale on the vertical pole 2.1.

[0083] 8) Input cable load

[0084] Press key 3.3 on keyboard 3 of controller to input cable load parameters, including cable cross-sectional area As, deadweight of a single photovoltaic panel G, number of photovoltaic panels arranged in one span N, and number of cables directly supporting the assembly m.

[0085] 9) Output sag and cable force test results

[0086] The controller 3 contains a calculation program, which calculates the cable force and sag according to the input load parameters and the measured data and displays them on the controller display screen 3.1. The calculation program is as follows:

[0087]

[0088] f=h1-h2

[0089]

[0090] The present invention has been put into use in a mountain photovoltaic project and a deep-water fish pond photovoltaic complementary photovoltaic project. The flexible photovoltaic support of the mountain photovoltaic project adopts a two-cable structure. After the assembly is installed, it is visually observed that the sag in the mid-span of the flexible photovoltaic support cables of a part of the project is large. Entrusted by the owner, the present invention was used to detect the cable force and sag of the mountain photovoltaic project, and the test results were used as the basis for project acceptance. The flexible photovoltaic supports of this project are arranged all over the mountains, and the detection work is difficult. The present invention has played the role of portability and convenience of operation in the detection operation, and completed the detection of all the support cables of the project in a short time. According to the internal force test data of the cables, it was found that 43% of the cable sag and cable force of the project did not meet the design requirements. After the test results were fed back to the owner, the owner required the construction unit to carry out reinforcement tensioning, and finally eliminated the quality problems of the project. The detection process of one span of the cables in the project is as follows:

[0091] According to the design documents, the cable uses 1860Mpa, 15.2mm diameter steel strand, and the module uses a certain manufacturer's 550Wp, DAS-DH144PA model module, with 14 modules arranged in each span. The controller selects the steel strand of this specification, and the instrument database automatically reads the nominal cross-sectional area of ​​the steel strand as 140mm2; the operator selects the photovoltaic module, and the instrument database automatically reads the module weight as 32.7kg; one of the span cables of this project was tested by the above-mentioned test method 1, and it was found that L1 = 17650mm, α = 28.3°; L3 = 6550mm, β = 27.35°.

[0092] The encapsulated program in the manipulator automatically calculated that the cable mid-span sag is 201.4mm and the cable force is 38.938kN. The program calculation process is as follows:

[0093]

[0094] q=0.15658(N / mm)

[0095]

[0096] f=201.4(mm)

[0097]

[0098] F = 38938 (N) = 38.938 (kN);

[0099] Where q is the converted uniform linear load, ρ is the cable material density which is 7850kg / m3, g is the acceleration of gravity which is 9.8N / kg, f is the sag, and F is the cable force.

[0100] The design document requires that the cable mid-span sag must be f≤L1 / 150, i.e. f≤117.7mm, and the cable force F must reach 67kN; after testing by the present invention, the mid-span sag f=201.4mm, and the cable force F=38.938kN; the cable construction of the flexible photovoltaic bracket in this project does not meet the design requirements, and there are quality problems in the cable tensioning construction, and the acceptance is unqualified! After the test, the project owner was fed back and the construction unit was required to reinforce and tension the cables again. During the reinforcement and tensioning, the cable anchor was removed, and the cable force acted on the through-hole jack. The jack oil pressure gauge showed that the pressure-relative cable force value was 38.3kN, which was almost equal to the cable force measured by the present invention, proving the accuracy of the cable force measurement of the present invention. After reinforcement and tensioning, the sag of the cable mid-span of the flexible photovoltaic bracket was significantly reduced visually, and the project quality was effectively controlled.

[0101] The flexible photovoltaic bracket of the deep-water fish pond photovoltaic complementary photovoltaic project adopts a two-cable structure. After several typhoons during the service stage of the project structure, it was observed that the sag of the mid-span of the cables of some flexible photovoltaic brackets of the project increased. The project was erected over a deep and wide fish pond, and it was difficult for surveyors to reach the mid-span area of ​​the flexible bracket, and it was difficult to detect the sag of the cable mid-span. Entrusted by the owner, the present invention was used to detect the cable force and sag of the mountain photovoltaic project, and the test results were used as the basis for post-disaster evaluation of the project. The flexible photovoltaic brackets of the project are spread over irregular deep-water fish ponds in the field area. It is difficult for inspectors to reach the waters of the fish ponds to carry out measurement work, and the detection work is difficult. The present invention has played the role of portability and convenience of operation in the detection operation, and completed the detection of all the bracket cables of the project in a short time. According to the test data, 20% of the cable sag and cable force of the project did not meet the service internal force requirements of the original design structure. After the test results were fed back to the owner, the owner reinforced and tensioned the cables whose sag increased and did not meet the original design requirements, and finally eliminated the quality problems of the project.

[0102] The inspection process of one of the span cables in this project is as follows:

[0103] According to the original design documents, the cables of this project use 1860Mpa, 17.8mm diameter steel strands, and the modules use 615Wp, JAM72D42615 / LB modules from a certain manufacturer, with 28 modules arranged in each span. The controller selects the steel strands of this specification, and the instrument database automatically reads the nominal cross-sectional area of ​​the steel strand as 191mm2; the operator selects the photovoltaic module, and the instrument database automatically reads the module weight as 34.6kg;

[0104] After testing one of the span cables of the project using the second testing method as described above, the results showed that L1=33420mm, α=11.2°, h1=5200mm, h2=4890mm.

[0105] The calculation program in the manipulator automatically calculated that the cable mid-span sag is 201.4mm and the cable force is 38.938kN. The calculation process of the program is as follows:

[0106]

[0107] q=0.15978(N / mm)

[0108] f=h1-h2

[0109] f=5200-4890

[0110] f=310(mm)

[0111]

[0112] F=74779.97(N)=74.78(kN);

[0113] The design document requires that the cable mid-span sag must be f≤L1 / 150, i.e. f≤222.8mm, and the cable force F must reach 104kN; after testing by the present invention, it is found that the mid-span sag f=310mm, and the cable force F=74.78kN; after the project was subjected to several typhoons, the cable force and sag of the flexible photovoltaic bracket did not meet the design requirements, and the post-disaster quality evaluation of the project was "The flexible bracket, cable and sag of the project exceeded the design normal use state limit, and do not have the ability to continue to serve!". It is recommended that the owner take reinforcement measures to ensure that the structure is in the design normal use state and has the ability to serve! When the owner subsequently reinforced and tensioned the cable, it was found that the cable anchor end had slip marks, which confirmed that the cable internal force relaxation and increased sag were caused by the cable slippage under the typhoon load. During the reinforcement and tensioning, the cable anchor is removed, and the cable force acts on the through-hole jack. The jack oil pressure gauge shows that the relative cable force value is 73.6kN, which is almost equal to the cable force measured by the present invention, proving the accuracy of the cable force measurement of the present invention. After reinforcement and tensioning, the sag of the flexible photovoltaic bracket cable in the mid-span is effectively reduced, the project quality is effectively improved, and the structural safety is effectively guaranteed.

[0114] Obviously, the above is only a part of the embodiments of the present invention, not all of the embodiments. The above embodiments are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any combination, modification, equivalent replacement, improvement and all other embodiments that can be made by those of ordinary skill in the art within the spirit and principle of the present invention should be within the scope of protection of the present invention.

Claims

1. A device for detecting sag and cable force of a flexible photovoltaic support cable, characterized in that: The utility model comprises a measuring part and a positioning part. The measuring part comprises a first vertical pole. A distance measuring machine head is arranged at the top of the first vertical pole. The distance measuring machine head comprises a motor. A laser distance meter is arranged on the rotating shaft of the motor. A semicircular ruler of angle measurement is arranged on one side of the laser distance meter. The center of the semicircular ruler of angle measurement is arranged corresponding to the rotating shaft. A positioning scale one is arranged on the side of the semicircular ruler away from the laser distance meter. A bubble level is also arranged on the first vertical pole. The positioning part comprises a second vertical pole. A reflector is arranged at the top of the second vertical pole. A laser positioning circle is arranged at the center of the reflector. A laser sight circle is arranged concentrically in the laser positioning circle. A positioning scale two is arranged on one side of the reflector. A bubble level is arranged on the second vertical pole. The laser distance between the first positioning scale and the laser distance meter is equal to the distance between the second positioning scale and the laser sight circle.

2. The device for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: The first and second vertical poles are telescopic poles, and the pole bodies are provided with scales. The first and second vertical poles include lower pipe rods, the lower pipe rods are sleeved with upper pipe rods, and the lower pipe rods are provided with fastening bolts.

3. The device for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: A telescope is arranged on the first vertical pole.

4. The device for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: The first vertical pole is provided with a controller, which is electrically connected with the laser rangefinder and the motor; the controller is installed on the fuselage support, the fuselage support is connected with the first vertical pole through a spring clip, and a calculation program is provided in the controller.

5. The device for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: One end of the reflector connected to the second upright pole is provided with a reflector stiffening thick edge, the middle of the reflector stiffening thick edge is provided with a connecting bolt hole, and the reflector stiffening thick edge is connected to the second upright pole through the connecting bolt hole.

6. The device for detecting sag and cable force of a flexible photovoltaic support cable according to claim 4, characterized in that: A rubber gasket is arranged on the contact surface between the spring clip and the second vertical pole.

7. The method for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: It includes measuring the sag of the cable of the flexible photovoltaic support, combining the technical parameters of the flexible photovoltaic support and constructing the cable calculation equation through mechanical modeling method to solve the cable force; The method for measuring sag includes connecting two end points of the flexible photovoltaic support to form a straight line, keeping the angle of the straight line unchanged, adjusting the height of the straight line to be tangent to the bottom of the cable, the point where the straight line is tangent to the cable is the sag position, and the adjusted height of the straight line is the sag; The process of establishing the cable calculation equation includes: Based on the self-gravity of the cable, considering that the photovoltaic panels are evenly spaced on the cable, the self-gravity of the cable and the weight of the photovoltaic panel are equivalent to a uniform linear load through the principle of mechanical calculation, and the equation is established as follows: Where f is the sag, F is the cable force, L1 is the chord length of the cable, α is the angle between L1 and the horizontal plane, and q is the uniform linear load.

8. The method for detecting sag and cable force of a flexible photovoltaic support cable according to claim 1, characterized in that: The technical parameters include cable length, specifications, photovoltaic panel model and number of photovoltaic panels.

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