A stress calibration method for overhead line suspension points based on the lowest point adjustment method

Abstract

The present invention relates to a method for checking the stress of an overhead line suspension point based on a lowest point adjustment method. The method comprises the following steps: obtaining a comprehensive specific load and an allowable stress under various working conditions of the overhead line; judging which working condition is a control working condition and obtaining a curvature coefficient corresponding to the control working condition; assuming that the ratio of the horizontal projection length of the lowest point of the conductor sag at the conductor low suspension point to the entire gear is a lowest point adjustment coefficient t, and listing a suspension point stress coefficient equation f(t); listing an objective function g(t) when the suspension point stress just reaches a critical value specified in a specification, and solving the relationship between the lowest point adjustment coefficient t, the curvature coefficient, and the gear span, and calculating the maximum allowable height difference h(t) corresponding to the gear span L according to the above relationship; and according to the above steps, obtaining a plurality of groups of drawing series data corresponding to the gear span and the corresponding maximum allowable height difference h(t), drawing a suspension point stress critical curve, and performing overhead line suspension point stress checking according to the curve.

Description

Technical Field

[0001] The invention relates to an overhead line suspension point stress calibration method based on a lowest point adjustment method, and belongs to the technical field of overhead line suspension point stress calibration. Background Art

[0002] To ensure that the stress at the conductor suspension point of overhead transmission lines does not exceed 22.5% at average annual temperatures, regulations and specifications stipulate that the maximum operating stress at the suspension point should not exceed 1.1 times the horizontal stress at the lowest sag point. This regulation is primarily designed for mountainous areas where the sag angle near the conductor suspension point is large. If the suspension point tension exceeds the limit, measures such as loosening the conductor and lowering the tower height should be taken. However, because the catenary equation with height differences contains relatively complex transcendental functions, it is difficult to achieve a fast iterative solution in actual engineering applications, resulting in low efficiency in suspension point stress verification. Summary of the Invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the present invention proposes a method for verifying the stress of the overhead line suspension point based on the lowest point adjustment method. On the basis of studying the changing law of the catenary curvature, a simple and practical calculation formula is summarized, which is convenient for line engineering to draw a "suspension point stress critical curve". Engineering personnel can check the span and height difference according to this curve to check whether the suspension point stress meets the specification requirements.

[0004] The technical solutions of the present invention are as follows:

[0005] On the one hand, the present invention provides a method for checking the stress of an overhead line suspension point based on a lowest point adjustment method, comprising the following steps:

[0006] Obtain the comprehensive specific load and allowable stress of overhead lines under various working conditions, and obtain the span range and height difference range of overhead lines;

[0007] When the representative gear spacing is L and the height difference is h, determine which working condition is the suspension point stress control working condition and obtain the curvature coefficient x corresponding to the control working condition k ;

[0008] Assuming that the ratio of the horizontal projection length from the conductor's lower suspension point to the conductor's lowest sag point to the entire level is the lowest point adjustment coefficient t, the suspension point stress coefficient equation f(t) is listed according to the following formula:

[0009]

[0010] Where, when t>0, the lowest point of the sag falls in the gear; when t=0, the lowest point of the sag falls exactly at the low hanging point; when t<0, the lowest point of the sag is outside the gear;

[0011] According to the specification, the objective function g(t) is listed when the stress of the suspension point just reaches the critical value specified in the specification, and the lowest point adjustment coefficient t and curvature coefficient x are solved. k The relationship between gear spacing L;

[0012] Adjust the coefficient t and curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the gear spacing L is used to calculate the maximum allowable height difference h(t) corresponding to the gear spacing L;

[0013] According to the above steps, several sets of drawing series data corresponding to the span and the corresponding maximum allowable height difference h(t) are obtained, and the critical stress curve of the suspension point is drawn based on the drawing series data. The stress of the overhead line suspension point is checked based on the critical stress curve of the suspension point and the horizontal section positioning diagram of the line project.

[0014] As a preferred embodiment, the method of determining which working condition is the suspension point stress control working condition and obtaining the curvature coefficient x corresponding to the control working condition is as follows: k The specific method is:

[0015] Determine which working condition is the suspension point stress control working condition according to the following formula:

[0016]

[0017] Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v n The operation process of the value of , and the largest one is recorded as v max ; When v i =v max When v i The corresponding working condition is the control working condition;

[0018] x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k .

[0019] As a preferred embodiment, the formula of the objective function g(t) when the stress of the suspension point just reaches the critical value specified in the specification is listed in the combination with the specification, and the lowest point adjustment coefficient t and the curvature coefficient x are solved. k The specific formula for the relationship between θ and gear spacing L is:

[0020]

[0021] As a preferred embodiment, the adjustment coefficient t and the curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the maximum allowable height difference h(t) corresponding to the gear spacing L is calculated as follows:

[0022]

[0023] On the other hand, the present invention also proposes a stress calibration system for overhead line suspension points based on the lowest point adjustment method, comprising:

[0024] Parameter acquisition module, used to obtain the comprehensive specific load and allowable stress of the overhead line under various working conditions, and obtain the span range and height difference range of the overhead line;

[0025] The control working condition judgment module is used to judge which working condition is the suspension point stress control working condition when the representative gear spacing is L and the height difference is h, and obtain the curvature coefficient x corresponding to the control working condition k ;

[0026] The lowest point adjustment coefficient equation construction module is used to assume that the ratio of the horizontal projection length from the conductor's lowest suspension point to the conductor's lowest sag point to the entire level is the lowest point adjustment coefficient t, and the suspension point stress coefficient equation f(t) is listed according to the following formula:

[0027]

[0028] Where, when t>0, the lowest point of the sag falls in the gear; when t=0, the lowest point of the sag falls exactly at the low hanging point; when t<0, the lowest point of the sag is outside the gear;

[0029] The parameter relationship acquisition module is used to combine the specifications to list the objective function g(t) when the stress of the suspension point just reaches the critical value specified in the specifications, and solve the lowest point adjustment coefficient t and the curvature coefficient x k The relationship between gear spacing L;

[0030] Height difference calculation module, used to adjust coefficient t and curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the gear spacing L is used to calculate the maximum allowable height difference h(t) corresponding to the gear spacing L;

[0031] The stress verification module is used to obtain several sets of drawing series data corresponding to the span and the corresponding maximum allowable height difference h(t) based on the parameter relationship acquisition module and the height difference calculation module, draw the critical stress curve of the suspension point through the drawing series data, and perform stress verification of the overhead line suspension point based on the critical stress curve of the suspension point and the horizontal section positioning diagram of the line project.

[0032] As a preferred embodiment, the control working condition judgment module judges which working condition is the suspension point stress control working condition, and obtains the curvature coefficient x corresponding to the control working condition. k The specific method is:

[0033] Determine which working condition is the suspension point stress control working condition according to the following formula:

[0034]

[0035] Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v n The operation process of the value of , and the largest one is recorded as v max ; When v i =v max When v i The corresponding working condition is the control working condition;

[0036] x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k .

[0037] As a preferred embodiment, the parameter relationship acquisition module combines the specification to list the formula of the objective function g(t) when the suspension point stress just reaches the critical value specified in the specification, and solves the lowest point adjustment coefficient t and the curvature coefficient x k The specific formula for the relationship between θ and gear spacing L is:

[0038]

[0039] As a preferred embodiment, the height difference calculation module adjusts the coefficient t and the curvature coefficient x according to the lowest point. k The relationship between the gear spacing L and the maximum allowable height difference h(t) corresponding to the gear spacing L is calculated as follows:

[0040]

[0041] On the other hand, the present invention also proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, it implements the overhead line suspension point stress verification method based on the lowest point adjustment method as described in any embodiment of the present invention.

[0042] On the other hand, the present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the overhead line suspension point stress verification method based on the lowest point adjustment method as described in any embodiment of the present invention.

[0043] The present invention has the following beneficial effects:

[0044] The present invention provides a method for verifying the stress of the overhead line suspension point based on the lowest point adjustment method. The method addresses the disadvantage that the traditional catenary equation with height difference contains a relatively complex transcendental function in form, which is not easy to achieve a fast iterative solution when used in actual projects. By studying the variation law of the catenary curvature, an elementary function expression that does not require iterative calculation is given to calculate the lowest point adjustment coefficient, and then the maximum allowable height difference within the project span under specific meteorological conditions and conductor combinations is calculated. The suspension point stress calculated by the present invention based on the lowest point adjustment coefficient is approximately 0.143% smaller than the maximum allowable value (the suspension point stress is 1.0984 times the lowest point stress, meeting the requirement of being less than 1.1 times). Therefore, the curve error calculated in this way is small, and the absolute error reserves a margin of approximately 0.1 MPa. The method is relatively safe and can be widely used in actual projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of a method flow in an embodiment of the present invention;

[0046] Figure 2 Schematic diagram of a critical stress curve of a suspension point in an embodiment of the present invention;

[0047] Figure 3 Schematic diagram of the critical stress curve of the suspension point under the condition of ice cover control in an application example of the present invention;

[0048] Figure 4 This is the critical stress curve of the suspension point when the relaxation coefficient is 0.95 under the icing control condition in the application example of the present invention. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] It should be understood that the step numbers used herein are only for convenience of description and are not intended to limit the order in which the steps are to be executed.

[0051] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0052] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0053] The term "and / or" refers to and includes any and all possible combinations of one or more of the associated listed items.

[0054] Example 1:

[0055] See also Figure 1 This embodiment proposes a method for checking the stress of an overhead line suspension point based on a lowest point adjustment method, comprising the following steps:

[0056] Step S100: Obtain the comprehensive specific load and allowable stress of the overhead line under various working conditions. For the convenience of explanation, this embodiment specifically lists the comprehensive specific load and allowable stress under three working conditions as shown in Table 1:

[0057] Table 1: Comparison of load ratios and allowable stress of wires under various working conditions

[0058]

[0059] Maximum wind speed, annual average temperature, and icing are the operating conditions that may exceed the suspension point limit. The specific load, temperature, and allowable stress are all known. The span range and height difference range of the overhead line are also obtained.

[0060] Step S200: When the representative gear span is L (unit: m) and the height difference is h (positive value, unit: m), determine which of the three working conditions is the suspension point stress control working condition according to (Formula 1), and obtain the curvature coefficient x corresponding to the control working condition. k ;

[0061]

[0062] Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v nThe operation process of the value of , and the largest one is recorded as x max ; When v i =v max When v i The corresponding working condition is the control working condition; x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k ;

[0063] It should be noted that in engineering practice, the controlling operating condition can generally be directly determined based on meteorological conditions and engineering experience. The operating condition where the suspension point stress exceeds the limit is often due to maximum wind conditions in coastal areas and icing conditions in inland areas. Under the annual average stress condition, the suspension point stress exceeds the limit only for large spans exceeding 1000m. If the controlling operating condition is unclear, the average span of the project and the maximum possible height difference can be used to determine the controlling operating condition through trial calculation using Equation 1.

[0064] Step S300: Assume that the left suspension point of the conductor on the cross-section is the low suspension point, and the ratio of its horizontal projection length to the lowest point of the conductor sag to the entire level is the lowest point adjustment coefficient t. The suspension point stress coefficient equation f(t) is listed according to (Equation 2):

[0065]

[0066] Where L is the gear distance in meters; t is the ratio of the horizontal projection length from the low suspension point to the lowest point of the sag to the entire gear, which is referred to as the lowest point adjustment coefficient in this article. When t>0, the lowest point of the sag falls in the gear (an actual point); when t=0, the lowest point of the sag falls exactly at the low suspension point; when t<0, the lowest point of the sag is outside the gear (a virtual point).

[0067] Step S400: Combined with the specification, the objective function g(t) is listed according to (Formula 3) when the stress of the suspension point just reaches the critical value specified in the specification, and the lowest point adjustment coefficient t and the curvature coefficient x are solved. k The relationship between gear spacing L;

[0068]

[0069] Step S500: According to (Formula 4), adjust the coefficient t and the curvature coefficient x according to the lowest point. k The relationship between the gear spacing L and the gear spacing L is used to calculate the maximum allowable height difference h(t) corresponding to the gear spacing L;

[0070]

[0071] Where h(t) is the height difference expression, which is a function of the horizontal projection coefficient t from the low hanging point to the lowest point of the sag, and the unit is m.

[0072] Step S600: Calculate the allowable height difference h(t) (retain one decimal place) for a series of spans (200 m to 1000 m, with a step length of 100 m) according to (Equation 3) and (Equation 4), and generate a series of plot data for spans and allowable height differences. Then, based on these data, use the spreadsheet's chart function to select an XY scatter plot and plot a "suspension point stress critical curve." The plot data generated in this embodiment are shown in Table 2 below:

[0073] Table 2 Spreadsheet data format

[0074] Gear spacing L(m) Lowest point adjustment coefficient t Height difference h(m) 200 -5.53096 85.4 300 -3.35397 122.3 400 -2.26548 155.5 500 -1.61238 185.0 600 -1.17699 210.9 700 -0.86599 233.3 800 -0.63274 252.1 900 -0.45132 267.5 1000 -0.30619 279.5

[0075] The critical stress curve of the suspension point drawn according to the data in Table 2 is as follows Figure 2 As shown (for illustration only).

[0076] Step S601: Check the cross-sectional positioning diagram of the line project. Check the span and elevation range for each span. If the span (abscissa) and elevation difference (ordinate) fall below the critical curve of the suspension point stress, the suspension point stress on both sides of the span is within the limit. Otherwise, it exceeds the limit and engineering measures need to be taken (such as loosening the conductors, lowering the tower height, adjusting the line path, etc., which are not the focus of this embodiment) to reduce the suspension point stress. After taking these measures, the suspension point stress should be rechecked for that span until the span and elevation difference meet the requirements.

[0077] If measures are taken to relax the conductor, assuming that the span to be checked is L and the height difference is h0, the value of t when the relaxation coefficient is μ(<1) can be calculated using formula (5). Finally, h(t) is solved to see whether it is greater than the given height difference. If so, the stress at the suspension point meets the requirements. Otherwise, further relaxation is required. μ can be selected from a series such as 0.950, 0.925, 0.900, 0.875, 0.850, 0.825, and 0.800. When this range is exceeded, the relaxation calculation can be tried downward at intervals of 0.025 until h(t) ≥ h0 is satisfied.

[0078]

[0079] Where μ is the relaxation coefficient for the maximum service stress (if the annual average temperature is used, it is the relaxation coefficient for the annual average stress); d is the new constant term in the original g(t) equation, which replaces the original constant term 0.1 in (Equation 3) (keeping the original negative sign unchanged); x d It is the new curvature coefficient after the wire is relaxed. Generally, a wire relaxation coefficient of 0.875 can meet the requirements of most cases.

[0080] The traditional catenary equation with elevation difference contains a relatively complex transcendental function, which makes it difficult to achieve a fast iterative solution when used in actual engineering projects. The method proposed in this embodiment addresses this shortcoming. After studying the changing law of the catenary curvature, an elementary function expression that does not require iterative calculation is given to calculate the lowest point adjustment coefficient, and then the maximum allowable elevation difference within the engineering span range is calculated under specific meteorological conditions and conductor combinations.

[0081] According to calculations, the suspension point stress calculated by the method proposed in this embodiment, based on the lowest point adjustment coefficient, is approximately 0.143% less than the maximum allowable value (the suspension point stress is 1.0984 times the lowest point, meeting the requirement of less than 1.1 times). This results in a small error in the calculated curve, with an absolute error margin of approximately 0.1 MPa. This method is relatively safe and can be widely used in actual projects. The method proposed in this embodiment is primarily used to verify the suspension point stress of conductors or ground wires during the construction drawing design phase and is applicable to all voltage levels.

[0082] To demonstrate the effectiveness and superiority of the calculation method proposed in this embodiment, a specific application example is provided below:

[0083] For a certain line, the specific load and allowable horizontal stress of the possible control working condition of the known suspension point stress are shown in Table 3:

[0084] Table 3: Specific load and allowable horizontal stress of wires

[0085]

[0086] Now, the critical stress curve of the suspension point is drawn according to the data provided in Table 3. Taking the average span of 500m and the maximum height difference of 200m as an example, the v calculated according to (Formula 1) in this embodiment is i The values ​​are shown in Table 4:

[0087] Table 4: Judgment of control conditions

[0088]

[0089]

[0090] It can be seen from Table 4 that when the average span is 500m and the maximum height difference is 200m, the stress control condition of the suspension point is the design icing condition. k =4.69565×10 -4 / m.

[0091] According to (Formula 3) and (Formula 4) in this embodiment, the data shown in Table 5 are calculated:

[0092] Table 5 Critical curve data of suspension points under icing control

[0093] Gear spacing L(m) Lowest point adjustment coefficient t Height difference h(m) L t h 200 -3.6866 82.4 300 -2.1244 115.6 400 -1.3433 143.7 500 -0.8746 166.9 600 -0.5622 185.2 700 -0.3390 198.7 800 -0.1716 207.5 900 -0.0415 211.6 1000 0.0627 211.0

[0094] According to Table 5, the stress curve of the suspension point is drawn as follows: Figure 3 shown.

[0095] The existing first-stage span is 600m and the height difference is 230m. The analysis process for determining whether the stress at the high suspension point exceeds the limit is as follows:

[0096] According to step S601, the coordinates of the point with a span of 600m and a height difference of 230m are (600, 230). Figure 3 From the curve, we can see that this point is above the curve, so we know that the stress of this high suspension point exceeds the limit, and certain measures should be taken in engineering.

[0097] Because the high hanging point stress of this gear exceeds the limit, it is proposed to reduce the maximum service stress by 5%. The process of determining whether the requirements of the specification for hanging point stress can be met is as follows:

[0098] If the conductor is loosened to reduce the maximum service stress by 5% from 92 MPa to 87.4 MPa, then (Equation 5) yields:

[0099]

[0100] From the above calculation results, we can know that h(t)>230m, so it can meet the requirements, and there is a large margin space after relaxation. Redraw the suspension point stress curve according to the method of step S600. Figure 4 shown.

[0101] from Figure 4 It can also be seen that the point (600,230) is within the safe area below the curve, so a 5% reduction in the maximum service stress can meet the specification requirements.

[0102] As can be seen from the above application examples, the method proposed in this embodiment avoids the use of more complex transcendental function calculations and can calculate the critical stress curve of the suspension point under specific meteorological conditions and conductor combinations without program iteration. It is particularly easy to achieve rapid calculations through spreadsheets or ordinary scientific calculators, and of course it is also suitable for computer programming.

[0103] The method proposed in this embodiment uses the lowest point adjustment coefficient as a parameter to convert the stress of the suspension point into the horizontal sag lowest point position change relationship for analysis and calculation when the given parameters are known. It can be combined with the intuitive feeling of the overhead line cross-section diagram for analysis, which is more convenient for engineers to enhance their perceptual understanding of the changes in the stress state of the wires. Its main formulas are (Formula 2), (Formula 3) and (Formula 4). The mathematical model is simple and is very convenient whether it is calculated manually or using a spreadsheet or computer programming. Therefore, the application effect is very significant.

[0104] Example 2:

[0105] This embodiment provides a system for checking stress at the overhead line suspension point based on a lowest point adjustment method, including:

[0106] A parameter acquisition module is used to obtain the comprehensive specific load and allowable stress of the overhead line under various working conditions, and to obtain the span range and height difference range of the overhead line; this module is used to implement the function of step S100 in the first embodiment, and will not be repeated here;

[0107] The control working condition judgment module is used to judge which working condition is the suspension point stress control working condition when the representative gear spacing is L and the height difference is h, and obtain the curvature coefficient x corresponding to the control working condition k ; This module is used to implement the function of step S200 in Example 1, and will not be repeated here;

[0108] The lowest point adjustment coefficient equation construction module is used to assume that the ratio of the horizontal projection length from the conductor's lowest suspension point to the conductor's lowest sag point to the entire level is the lowest point adjustment coefficient t, and the suspension point stress coefficient equation f(t) is listed according to the following formula:

[0109]

[0110] Wherein, when t>0, the lowest point of the sag falls in the gear; when t=0, the lowest point of the sag falls exactly at the low hanging point; when t<0, the lowest point of the sag is outside the gear; this module is used to implement the function of step S300 in the first embodiment, and will not be repeated here;

[0111] The parameter relationship acquisition module is used to combine the specifications to list the objective function g(t) when the stress of the suspension point just reaches the critical value specified in the specifications, and solve the lowest point adjustment coefficient t and the curvature coefficient x k and the relationship between the gear distance L; this module is used to implement the function of step S400 in the first embodiment, which will not be repeated here;

[0112] Height difference calculation module, used to adjust coefficient t and curvature coefficient x according to the lowest point kand the gear spacing L, and calculate the maximum allowable height difference h(t) corresponding to the gear spacing L; this module is used to implement the function of step S500 in the first embodiment, which will not be repeated here;

[0113] The stress verification module is used to obtain several sets of drawing series data corresponding to the span and the corresponding maximum allowable height difference h(t) based on the parameter relationship acquisition module and the height difference calculation module, draw the critical curve of the suspension point stress through the drawing series data, and perform stress verification of the overhead line suspension point based on the critical curve of the suspension point stress and the line project cross-section positioning diagram; this module is used to implement the functions of steps S600 and S601 in Example 1, and will not be repeated here.

[0114] As a preferred implementation of this embodiment, the control working condition judgment module determines which working condition is the suspension point stress control working condition, and obtains the curvature coefficient x corresponding to the control working condition. k The specific method is:

[0115] Determine which working condition is the suspension point stress control working condition according to the following formula:

[0116]

[0117] Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v n The operation process of the value of , and the largest one is recorded as v max ; When v i =v max When v i The corresponding working condition is the control working condition;

[0118] x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k .

[0119] As a preferred implementation of this embodiment, the parameter relationship acquisition module combines the specifications to list the formula of the objective function g(t) when the suspension point stress just reaches the critical value specified in the specifications, and solves the lowest point adjustment coefficient t and the curvature coefficient x K The specific formula for the relationship between θ and gear spacing l is:

[0120]

[0121] As a preferred implementation of this embodiment, the height difference calculation module adjusts the coefficient t and the curvature coefficient x according to the lowest point. k The relationship between the gear spacing L and the maximum allowable height difference h(t) corresponding to the gear spacing L is calculated as follows:

[0122]

[0123] Example 3:

[0124] This embodiment proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, it implements the overhead line suspension point stress verification method based on the lowest point adjustment method as described in any embodiment of the present invention.

[0125] Example 4:

[0126] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for verifying the stress of the overhead line suspension point based on the lowest point adjustment method as described in any embodiment of the present invention is implemented.

[0127] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can represent: a, b, c, a and b, a and c, b and c or a and b and c, where a, b, c can be single or multiple.

[0128] Those skilled in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented using a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0129] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0130] In the several embodiments provided in this application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of this application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), magnetic disk or optical disk, and other media that can store program code.

[0131] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for checking the stress of overhead line suspension points based on the lowest point adjustment method, characterized in that: The following steps are involved: Obtain the comprehensive specific load and allowable stress of overhead lines under various working conditions, and obtain the span range and height difference range of overhead lines; When the representative gear spacing is L and the height difference is h, determine which working condition is the suspension point stress control working condition and obtain the curvature coefficient x corresponding to the control working condition k ; Assuming that the ratio of the horizontal projection length from the conductor's lower suspension point to the conductor's lowest sag point to the entire level is the lowest point adjustment coefficient t, the suspension point stress coefficient equation f(t) is listed according to the following formula: In the formula, when t>0, the lowest point of the sag falls in the middle of the gear; When t=0, the lowest point of the sag falls exactly at the low hanging point; when t<0, the lowest point of the sag is outside the gear; According to the specification, the objective function g(t) is listed when the stress of the suspension point just reaches the critical value specified in the specification, and the lowest point adjustment coefficient t and curvature coefficient x are solved. k The relationship between gear spacing L; Adjust the coefficient t and curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the gear spacing L is used to calculate the maximum allowable height difference h(t) corresponding to the gear spacing L; According to the above steps, several sets of drawing series data corresponding to the span and the corresponding maximum allowable height difference h(t) are obtained, and the critical stress curve of the suspension point is drawn based on the drawing series data. The stress of the overhead line suspension point is checked based on the critical stress curve of the suspension point and the horizontal section positioning diagram of the line project.

2. The method for checking the stress of the overhead line suspension point based on the lowest point adjustment method according to claim 1, characterized in that: The method of determining which working condition is the suspension point stress control working condition and obtaining the curvature coefficient x corresponding to the control working condition is as follows: k The specific method is: Determine which working condition is the suspension point stress control working condition according to the following formula: Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v n The operation process of the value of , and the largest one is recorded as v max ; When v i =v max When v i The corresponding working condition is the control working condition; x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k .

3. The method for checking the stress of the overhead line suspension point based on the lowest point adjustment method according to claim 1, characterized in that: The above-mentioned combination of specifications lists the formula of the objective function g(t) when the stress of the suspension point just reaches the critical value specified in the specification, and solves the lowest point adjustment coefficient t and the curvature coefficient x k The specific formula for the relationship between θ and gear spacing L is:

4. The method for checking the stress of the overhead line suspension point based on the lowest point adjustment method according to claim 3, characterized in that: The adjustment coefficient t and the curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the maximum allowable height difference h(t) corresponding to the gear spacing L is calculated as follows:

5. An overhead line suspension point stress calibration system based on the lowest point adjustment method, characterized in that: include: Parameter acquisition module, used to obtain the comprehensive specific load and allowable stress of the overhead line under various working conditions, and obtain the span range and height difference range of the overhead line; The control working condition judgment module is used to judge which working condition is the suspension point stress control working condition when the representative gear spacing is L and the height difference is h, and obtain the curvature coefficient x corresponding to the control working condition k ; The lowest point adjustment coefficient equation construction module is used to assume that the ratio of the horizontal projection length from the conductor's lowest suspension point to the conductor's lowest sag point to the entire level is the lowest point adjustment coefficient t, and the suspension point stress coefficient equation f(t) is listed according to the following formula: In the formula, when t>0, the lowest point of the sag falls in the middle of the gear; When t=0, the lowest point of the sag falls exactly at the low hanging point; when t<0, the lowest point of the sag is outside the gear; The parameter relationship acquisition module is used to combine the specifications to list the objective function g(t) when the stress of the suspension point just reaches the critical value specified in the specifications, and solve the lowest point adjustment coefficient t and the curvature coefficient x k The relationship between gear spacing L; Height difference calculation module, used to adjust coefficient t and curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the gear spacing L is used to calculate the maximum allowable height difference h(t) corresponding to the gear spacing L; The stress verification module is used to obtain several sets of drawing series data corresponding to the span and the corresponding maximum allowable height difference h(t) based on the parameter relationship acquisition module and the height difference calculation module, draw the critical stress curve of the suspension point through the drawing series data, and perform stress verification of the overhead line suspension point based on the critical stress curve of the suspension point and the horizontal section positioning diagram of the line project.

6. The overhead line suspension point stress calibration system based on the lowest point adjustment method according to claim 5, characterized in that: The control working condition judgment module judges which working condition is the suspension point stress control working condition and obtains the curvature coefficient x corresponding to the control working condition. k The specific method is: Determine which working condition is the suspension point stress control working condition according to the following formula: Where, L represents the gear distance; i is the serial number of the corresponding working condition; x i is the curvature coefficient of the corresponding working condition; γ i is the specific load of the corresponding working condition; σ i is the corresponding published allowable stress; v i is the estimated value of the vertical component of the suspension point stress converted from the vertical load; max is the value for comparing v1 to v n The operation process of the value of , and the largest one is recorded as v max ; When v i =v max When v i The corresponding working condition is the control working condition; x k For when v i =v max When x is recorded i is the curvature coefficient x corresponding to the control condition k .

7. The overhead line suspension point stress calibration system based on the lowest point adjustment method according to claim 5, characterized in that: The parameter relationship acquisition module combines the specifications to list the formula of the objective function g(t) when the suspension point stress just reaches the critical value specified in the specifications, and solves the lowest point adjustment coefficient t and the curvature coefficient x k The specific formula for the relationship between θ and gear spacing L is:

8. The overhead line suspension point stress calibration system based on the lowest point adjustment method according to claim 7, characterized in that: The height difference calculation module adjusts the coefficient t and the curvature coefficient x according to the lowest point k The relationship between the gear spacing L and the maximum allowable height difference h(t) corresponding to the gear spacing L is calculated as follows:

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the overhead line suspension point stress verification method based on the lowest point adjustment method as described in any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the overhead line suspension point stress calibration method based on the lowest point adjustment method as described in any one of claims 1 to 4 is implemented.

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