Method and system for calculating sag stress of overhead lines by using shape coefficient state equation

Abstract

The present invention relates to a method for calculating the sag stress of an overhead line by using a shape coefficient state equation. The method comprises the following steps: obtaining the comprehensive specific load, air temperature, representative span and allowable stress under various working conditions of the overhead line; and obtaining the comprehensive specific load and air temperature of the working condition to be determined; judging which working condition is the control working condition, defining the shape coefficient of the working condition to be determined as u, listing the shape coefficient state equation f(u) and its first-order derivative function g(u); calculating the shape coefficient u of the working condition to be determined according to the shape coefficient state equation f(u) and its first-order derivative function g(u); and calculating the sag f and stress σ of the working condition to be determined according to the calculated shape coefficient u of the working condition to be determined.

Description

Technical Field

[0001] The present invention relates to a method and a system for calculating the sag stress of an overhead line through a shape coefficient state equation, and belongs to the technical field of power facility parameter calculation. Background Art

[0002] For overhead transmission lines, the stress state equation is generally used to iteratively solve the stress first and then solve the sag.

[0003] For example, the invention patent with the patent publication number "CN110569603A" discloses a method for calculating the stress sag of overhead lines with non-uniform loads. The method uses the line length parameters of each section in the overhead line tension section under different operating conditions to calculate the comprehensive line length parameters of the overhead line under different operating conditions in the entire tension section; calculates the control condition coefficient based on the comprehensive line length parameters under pre-given working conditions, and sets the working condition corresponding to the maximum control condition coefficient as the control working condition; according to the control working condition, uses the unified state equation of overhead line mechanics with non-uniform loads to calculate the stress of each working condition to be calculated; calculates the sag position of the overhead line with non-uniform loads and the sag at each point under the working condition to be calculated.

[0004] The above patent also calculates stress first through the state equation and then solves the sag. However, since stress is an abstract physical concept, people cannot observe and understand it intuitively, resulting in unclear concepts, which is not conducive to the cognition and understanding of designers and construction workers, and the calculation process is also relatively complicated. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention proposes a method and system for calculating the sag stress of overhead lines through the shape coefficient state equation, opening up a new idea. The shape coefficient is calculated first, then the sag is calculated, and finally the stress is calculated. The use of macroscopically perceptible and measurable physical quantities as parameters will help designers and construction personnel increase their perceptual understanding and improve their problem-solving skills.

[0006] The technical solutions of the present invention are as follows:

[0007] In one aspect, the present invention provides a method for calculating the sag stress of an overhead line by using a shape coefficient state equation, comprising the following steps:

[0008] Obtain the comprehensive load ratio, temperature, representative span and allowable stress of the overhead line under various working conditions; and obtain the comprehensive load ratio and temperature of the working condition to be determined;

[0009] Determine which operating condition is the control operating condition according to the following formula:

[0010]

[0011] Where, L represents the gear distance; i corresponds to the serial number of each working condition; x iis the correction coefficient corresponding to each working condition, which is a dimensionless proportional value; e is the base of the natural logarithm; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the comparison between C1~C n The smallest value is recorded as C min When C i =C min When C i The corresponding working condition is the control working condition, and the t at this time is recorded. i is the temperature t corresponding to the control condition k , at this time x i is the correction coefficient x corresponding to the control condition k , the comprehensive load ratio γ i is the comprehensive load ratio corresponding to the control condition γ k Where, is the approximate line length coefficient;

[0012] Record C min and x k , assuming that the correction coefficient of the working condition to be determined is u, the correction state equation f(u) and its first-order derivative function g(u) are listed according to the following formula:

[0013]

[0014] Where γ is the comprehensive load ratio of the working condition to be determined, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function;

[0015] According to the correction state equation f(u) and its first-order derivative function g(u), the correction coefficient u of the working condition to be determined is calculated according to the following formula:

[0016]

[0017] Where u0 is the initial value of the correction coefficient and is a dimensionless proportional coefficient;

[0018] Calculate the sag f and stress σ of the working condition to be determined based on the calculated shape coefficient u of the working condition to be determined:

[0019]

[0020] Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L.

[0021] As a preferred embodiment, when a certain observation span L in the continuous tension section m If the span L is different from the representative span L in the tension section, the span L is calculated according to the following formula and the observed span is L mThe corresponding sag f at the center of the gear spacing under the working condition to be determined c And the span is L, the observation span is L m The corresponding stress σ at the center of the gear spacing under the working condition to be determined is c :

[0022]

[0023] Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear; β is the gear spacing L m The height difference angle corresponding to the gear.

[0024] On the other hand, the present invention also provides a system for calculating the sag stress of an overhead line using a correction coefficient state equation, comprising:

[0025] The basic parameter acquisition module is used to obtain the comprehensive load ratio, temperature, representative span and allowable stress of the overhead line under various working conditions; and obtain the comprehensive load ratio and temperature of the working condition to be determined;

[0026] The control condition analysis module is used to determine which condition is the control condition according to the following formula:

[0027]

[0028] Where, L represents the gear distance; i corresponds to the serial number of each working condition; x i is the correction coefficient corresponding to each working condition, which is a dimensionless proportional value; e is the base of the natural logarithm; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the comparison between C1~C n The smallest value is recorded as C min When C i =C min When C i The corresponding working condition is the control working condition, and the t at this time is recorded. i is the temperature t corresponding to the control condition k , at this time x i is the correction coefficient x corresponding to the control condition k , the comprehensive load ratio γ i is the comprehensive load ratio corresponding to the control condition γ k Where, is the approximate line length coefficient; record C min and x k ;

[0029] The equation building module is used to assume that the correction coefficient of the working condition to be determined is u, and list the correction state equation f(u) and its first-order derivative function g(u) according to the following formula:

[0030]

[0031] Where γ is the comprehensive load ratio of the working condition to be determined, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function;

[0032] The shape coefficient calculation module is used to calculate the shape coefficient u of the working condition to be determined according to the shape state equation f(u) and its first-order derivative function g(u) according to the following formula:

[0033]

[0034] Where u0 is the initial value of the correction coefficient and is a dimensionless proportional coefficient;

[0035] The sag stress calculation module is used to calculate the sag f and stress σ of the working condition to be determined based on the calculated shape coefficient u of the working condition to be determined:

[0036]

[0037] Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L.

[0038] As a preferred embodiment, when a certain observation span L in the continuous tension section m When the span L is different from the representative span L in the tension section, the sag stress calculation module calculates the span L according to the following formula. The observed span is L m The corresponding sag f at the center of the gear spacing under the working condition to be determined c And the span is L, the observation span is L m The corresponding stress σ at the center of the gear spacing under the working condition to be determined is c :

[0039]

[0040] Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear; β is the gear spacing L m The height difference angle corresponding to the gear.

[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 method for calculating the sag stress of the overhead line through the correction coefficient state equation as described in any embodiment of the present invention.

[0042] On the other hand, the present invention further proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the sag stress of an overhead line by using a correction coefficient state equation 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 calculating the sag stress of overhead lines by using a correction shape coefficient state equation. Based on the shortcomings of the current status of the power transmission line industry (first iteratively solving stress and then solving sag), a new state equation is given with macroscopically measurable dimensionless shape coefficients as variables, avoiding the abstract physical concept of stress and making the original state equation easier to understand from an intuitive perspective. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] The term "and / or" refers to and includes any and all possible combinations of one or more of the associated listed items.

[0051] Example 1:

[0052] See also Figure 1 This embodiment proposes a method for calculating the sag stress of an overhead line using a shape coefficient state equation, comprising the following steps:

[0053] Step S100: Obtain the comprehensive specific load, temperature, representative span, and allowable stress of the overhead line under various operating conditions; and obtain the comprehensive specific load and temperature of the operating condition to be determined. For details, see Table 1. This embodiment provides examples of four operating conditions, including a maximum wind condition, a minimum temperature condition, an annual average temperature condition, and an icing condition.

[0054] Table 1: Comprehensive load ratio, air temperature and allowable horizontal stress of wires under various working conditions

[0055]

[0056] As shown in Table 1, the maximum wind, minimum temperature, annual average temperature, and icing are possible control conditions. The sag corresponding to a specific representative span L can only be controlled by one of them. The comprehensive specific load, temperature, and allowable stress of the four possible control conditions are all known. The specific load γ and temperature t of the working condition to be determined are also known. Other known conditions include the conductor temperature expansion coefficient α (1 / ℃) and the elastic coefficient E (N / mm 2 ).

[0057] Step S200: Determine which of the four possible operating conditions is the control operating condition according to the following formula (1), and record the corresponding C min Value and t k value;

[0058]

[0059] Where, L represents the gear distance in meters; i corresponds to the sequence number of the four working conditions in Table 1; x i is the correction coefficient corresponding to the four working conditions, which is a dimensionless proportional value; e is the base of the natural logarithm, which can be 2.71828; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the operation process of comparing the values ​​of C1, C2, C3, and C4, and the smallest one is recorded as C min ;when At this time, record the temperature, shape factor and load ratio corresponding to the control condition as t k 、x k , γ k , these parameters are only used as intermediate variables, but if a program calculation book is compiled, these parameters are generally required to be used as output parameters; where, is the approximate line length coefficient;

[0060] Step S300: Assume that the correction coefficient of the working condition to be determined is u (unknown variable), and list the correction state equation f(u) and its first-order derivative function g(u) according to (Equation 2):

[0061]

[0062] In the formula, γ is the comprehensive load ratio of the working condition to be determined in Table 1, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function, rather than setting its value to 0. When the manually selected initial value u0 is substituted into it, its calculated value is not 0.

[0063] Step S400: Calculate the correction coefficient u of the working condition to be determined according to the correction state equation f(u) and its first-order derivative function g(u) as follows (Equation 3):

[0064]

[0065] Where u0 is the initial value of the correction coefficient, and x in (Equation 1) i The physical concepts are the same, both are dimensionless proportional coefficients. (Equation 3) is originally an iterative calculation process. According to numerical experiments, in most cases, it only needs to be repeated four times to meet the requirements. Therefore, the formula is directly listed in the form of four repetitions. When special circumstances arise, when the absolute value of (1-u / u3) is greater than 0.001, the number of iterations can be increased.

[0066] Step S500: Calculate the sag f and stress σ of the working condition to be determined according to the calculated shape correction coefficient u of the working condition to be determined according to (Formula 4):

[0067]

[0068] Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and the unit is m; σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L, and the unit is MPa.

[0069] As a preferred implementation of this embodiment, step S501 is further included, specifically:

[0070] When a certain observation span L in the continuous tension section m When the span L is different from the representative span L in the tension section, the sag f of the observed span at the center of the span of the working condition to be determined is calculated according to (Equation 5): c and the stress σ at the center of the span c :

[0071]

[0072] Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear, in m; β is the gear spacing L m The height difference angle corresponding to the gear is in rad; f c The representative span is L, the observation span is L m The sag at the center of the gear spacing under the corresponding working condition to be determined is in m; σ c The representative span is L, the observation span is Lm The stress at the center of the gear span under the corresponding working condition to be determined, in MPa.

[0073] The method proposed in this embodiment addresses the shortcomings of the current state of the power transmission line industry (which iteratively solves stress first, then sag). Using the macroscopically measurable dimensionless shape coefficient as a variable, a new state equation is proposed, avoiding the abstract physical concept of stress and making the existing state equation easier to understand intuitively. The shape equation is not a simple transformation of the state equation, but a new cubic equation that solves the shape by the shape. This cubic equation has 1st, 2nd, and 3rd order terms and a constant term, unlike the stress state equation, which lacks a linear term.

[0074] According to calculations, the maximum relative error between the conductor stress calculated by the method provided in this embodiment and the traditional method is on the order of 5E-4 (calculated based on a maximum sag of 80m at a 1000m span, the absolute error is only 4.0cm), which can be considered completely equivalent in actual engineering.

[0075] The method proposed in this embodiment can be applied to various aspects such as design, construction, and project acceptance, and is applicable to all voltage levels.

[0076] The calculation method proposed in this embodiment is based on the thinking of "observing phenomena" in ancient astronomy, takes the dimensionless proportional coefficient as a variable, and combines personal understanding to give a state equation based on the correction coefficient and its derivative function formula (Formula 2); and when the gear span of the continuous gear is different from the representative gear span and there is a height difference, (Formula 5) is given to calculate the sag and stress at the center of the gear span.

[0077] To demonstrate the effectiveness and superiority of the calculation method proposed in this embodiment, a specific application example is provided below:

[0078] For a certain line, the representative span is 500m, the conductor temperature expansion coefficient is α=20.5E-6(1 / ℃), the elastic coefficient is E=65000(N / mm 2 ), the conductor is not covered with ice, the known possible control load and operating stress are shown in Table 2:

[0079] Table 2: Comprehensive load ratio, air temperature and allowable horizontal stress of wires

[0080]

[0081] The sag and stress solutions under high temperature conditions are now carried out as follows:

[0082] According to the formula in this paper, C i The values ​​are shown in Table 3:

[0083] Table 3 Control condition judgment

[0084] Working condition name <![CDATA[C i ]]> <![CDATA[t i ]]> <![CDATA[σ i ,x i ]]> Maximum wind 1.002131 <![CDATA[t1=15]]> <![CDATA[σ1=92,x1=0.076087]]> lowest temperature 1.004123 <![CDATA[t2=-5]]> <![CDATA[σ2=92,x2=0.084239]]> Average annual temperature 1.011352 <![CDATA[t3=15]]> <![CDATA[σ3=57.5,x3=0.134783]]> Ice Cover / / /

[0085] According to Table 3, we can judge that the maximum wind is C1=1.002131=C min , so the control condition is the maximum wind, t k =15℃,C k =1.002131,x k =0.076087.

[0086] The calculated high temperature sag and stress are shown in Table 4:

[0087] Table 4: Iterative calculation process of sag and stress under high temperature conditions

[0088]

[0089] The calculated annual average temperature and minimum temperature sag and stress are shown in Table 5.

[0090] Table 5: Average and minimum temperature sag and stress iterative calculation process

[0091]

[0092]

[0093] According to Tables 4 and 5, the third calculation (excluding the initial value calculation) already meets the requirements. Due to different equations of state, the calculation results vary slightly, but the relative errors are 1.12E-05, 2.24E-04, and 4.05E-04 at high temperature, average annual temperature, and minimum temperature, respectively. These are negligible compared to the engineering sag acceptance specification requirement of no more than 2.5%. Given a certain span, sag and stress are inversely proportional, so the stress error is also on the order of 4E-04. Neither method has a substantial impact on conductor safety.

[0094] When the observation span is 600m and the elevation difference angle is 15°, calculate the sag and stress of the string at 15° as follows:

[0095] Directly according to the results of Table 5, substitute into (Formula 5), ​​we get:

[0096]

[0097] The above analysis shows that as the temperature decreases, the sag calculated using the method of this embodiment tends to decrease, while the stress tends to increase. Therefore, this method will help designers improve their understanding of the hazards of breeze vibration under low-temperature conditions. However, engineering verification is generally conducted at temperatures of 40°C or above, so it has no impact on actual engineering design.

[0098] The method proposed in this embodiment has no substantial impact on conductor safety compared to the traditional stress state equation method, and both methods meet actual engineering requirements in terms of accuracy. The method proposed in this embodiment opens up a completely new approach, first calculating the shape coefficient (form factor), then calculating the sag, and finally calculating the stress. Using macroscopically perceptible and measurable physical quantities as parameters, this method will help designers and construction personnel increase their perceptual understanding and improve their problem-solving skills. This is particularly convenient when designing conductor relaxation based on the absolute value of the design sag (a safety factor greater than the standard value of 2.5) in accordance with spatial crossing requirements. Furthermore, the method proposed in this embodiment is particularly easy to implement quickly using a spreadsheet or a common scientific calculator, and is also suitable for computer programming.

[0099] The method proposed in this embodiment uses the shape coefficient state equation method to calculate the shape coefficient, sag and stress of the overhead line when the parameters given in Table 1 are known. The main formulas are (Equation 1) and (Equation 2). The mathematical model is simple and is very convenient whether it is manual calculation, spreadsheet calculation or computer programming. Therefore, the application effect is very significant.

[0100] Example 2:

[0101] This embodiment provides a system for calculating the sag stress of an overhead line using a shape coefficient state equation, including:

[0102] A basic parameter acquisition module is used to obtain the comprehensive specific load, temperature, representative span, and allowable stress of the overhead line under various operating conditions; and to obtain the comprehensive specific load and temperature of the operating condition to be determined. This module is used to implement the function of step S100 in the above-mentioned embodiment 1 and will not be repeated here;

[0103] A control operating condition analysis module, configured to determine which operating condition is a control operating condition according to the following formula. This module is configured to implement the function of step S200 in the first embodiment above and will not be described in detail here.

[0104]

[0105] Where, L represents the gear distance; i corresponds to the serial number of each working condition; x i is the correction coefficient corresponding to each working condition, which is a dimensionless proportional value; e is the base of the natural logarithm; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the comparison between C1~C n The smallest value is recorded as C min When C i =C min When C i The corresponding working condition is the control working condition, and the t at this time is recorded. i is the temperature t corresponding to the control conditionk , at this time x i is the correction coefficient x corresponding to the control condition k , the comprehensive load ratio γ i is the comprehensive load ratio corresponding to the control condition γ k Where, is the approximate line length coefficient; record C min and x k ;

[0106] An equation construction module is used to assume that the correction coefficient of the working condition to be determined is u, and to list the correction state equation f(u) and its first-order derivative function g(u) according to the following formula. This module is used to implement the function of step S300 in the above embodiment 1 and will not be repeated here;

[0107]

[0108] Where γ is the comprehensive load ratio of the working condition to be determined, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function;

[0109] A shape coefficient calculation module is used to calculate the shape coefficient u of the working condition to be determined according to the shape state equation f(u) and its first-order derivative function g(u) according to the following formula. This module is used to implement the function of step S400 in the above-mentioned embodiment 1 and will not be repeated here;

[0110]

[0111] Where u0 is the initial value of the correction coefficient and is a dimensionless proportional coefficient;

[0112] A sag stress calculation module, used to calculate the sag f and stress σ of the working condition to be determined based on the calculated shape correction coefficient u of the working condition to be determined. This module is used to implement the function of step S500 in the above-mentioned embodiment 1 and will not be repeated here;

[0113]

[0114] Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L.

[0115] As a preferred embodiment of this embodiment, when a certain observation span L in the continuous tension section m When the span L is different from the representative span in the tension section, the sag stress calculation module calculates the sag f of the observed span at the center of the span according to the following formula: c and the stress σ at the center of the span c This module is used to implement the function of step S501 in the above embodiment 1, and will not be described in detail here;

[0116]

[0117] Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear; β is the gear spacing L m The height difference angle corresponding to the gear; f c The representative span is L, the observation span is L m The sag at the center of the gear spacing under the corresponding working condition to be determined; σ c The representative span is L, the observation span is L m The corresponding stress at the center of the gear span under the working condition to be determined.

[0118] Example 3:

[0119] 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 method for calculating the sag stress of an overhead line by using a correction coefficient state equation as described in any embodiment of the present invention.

[0120] Example 4:

[0121] 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 calculating the sag stress of an overhead line by using a correction coefficient state equation as described in any embodiment of the present invention is implemented.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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 calculating the sag stress of an overhead line by using a shape coefficient state equation, characterized in that: The following steps are involved: Obtain the comprehensive load ratio, temperature, representative span and allowable stress of the overhead line under various working conditions; and obtain the comprehensive load ratio and temperature of the working condition to be determined; Determine which operating condition is the control operating condition according to the following formula: Where, L represents the gear distance; i corresponds to the serial number of each working condition; x i is the correction coefficient corresponding to each working condition, which is a dimensionless proportional value; e is the base of the natural logarithm; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the comparison between C1~C n The smallest value is recorded as C min When C i =C min When C i The corresponding working condition is the control working condition, and the t at this time is recorded. i is the temperature t corresponding to the control condition k , at this time x i is the correction coefficient x corresponding to the control condition k , the comprehensive load ratio γ i is the comprehensive load ratio corresponding to the control condition γ k Where, is the approximate line length coefficient; Record C min and x k , assuming that the correction coefficient of the working condition to be determined is u, the correction state equation f(u) and its first-order derivative function g(u) are listed according to the following formula: Where γ is the comprehensive load ratio of the working condition to be determined, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function; According to the correction state equation f(u) and its first-order derivative function g(u), the correction coefficient u of the working condition to be determined is calculated according to the following formula: Where u0 is the initial value of the correction coefficient and is a dimensionless proportional coefficient; Calculate the sag f and stress σ of the working condition to be determined based on the calculated shape coefficient u of the working condition to be determined: Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L.

2. The method for calculating the sag stress of an overhead line by using a correction coefficient state equation according to claim 1, characterized in that: When a certain observation span L in the continuous tension section m If the span L is different from the representative span L in the tension section, the span L is calculated according to the following formula and the observed span is L m The corresponding sag f at the center of the gear spacing under the working condition to be determined c And the span is L, the observation span is L m The corresponding stress σ at the center of the gear spacing under the working condition to be determined is c : Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear; β is the gear spacing L m The height difference angle corresponding to the gear.

3. A system for calculating the sag stress of overhead lines using a correction coefficient state equation, characterized in that: include: Basic parameter acquisition module, used to obtain the comprehensive load ratio, temperature, representative span and allowable stress under various working conditions of overhead lines; And obtain the comprehensive load ratio and temperature of the working condition to be determined; The control condition analysis module is used to determine which condition is the control condition according to the following formula: Where, L represents the gear distance; i corresponds to the serial number of each working condition; x i is the correction coefficient corresponding to each working condition, which is a dimensionless proportional value; e is the base of the natural logarithm; α is the temperature expansion coefficient of the wire; E is the elastic coefficient; t i is the temperature corresponding to each working condition; min is the comparison between C1~C n The smallest value is recorded as C min When C i =C min When C i The corresponding working condition is the control working condition, and the t at this time is recorded. i is the temperature t corresponding to the control condition k , at this time x i is the correction coefficient x corresponding to the control condition k , the comprehensive load ratio γ i is the comprehensive load ratio corresponding to the control condition γ k Where, is the approximate line length coefficient; record C min and x k ; The equation building module is used to assume that the correction coefficient of the working condition to be determined is u, and list the correction state equation f(u) and its first-order derivative function g(u) according to the following formula: Where γ is the comprehensive load ratio of the working condition to be determined, and t is the temperature corresponding to the working condition to be determined; f(u) = 0 is the objective function; The correction coefficient calculation module is used to calculate the correction coefficient u of the working condition to be determined according to the correction state equation f(u) and its first-order derivative function g(u) according to the following formula: Where u0 is the initial value of the correction coefficient and is a dimensionless proportional coefficient; The sag stress calculation module is used to calculate the sag f and stress σ of the working condition to be determined based on the calculated shape coefficient u of the working condition to be determined: Where f is the sag of the working condition to be determined corresponding to the gear spacing L, and σ is the horizontal stress of the working condition to be determined corresponding to the gear spacing L.

4. The system for calculating the sag stress of an overhead line by using a correction coefficient state equation according to claim 3, characterized in that: When a certain observation span L in the continuous tension section m If the span L is different from the representative span L in the tension section, the span L is calculated according to the following formula and the observed span is L m The corresponding sag f at the center of the gear spacing under the working condition to be determined c And the span is L, the observation span is L m The corresponding stress σ at the center of the gear spacing under the working condition to be determined is c : Where h is the observation span L m The absolute value of the height difference of the wire suspension point corresponding to the gear; β is the gear spacing L m The height difference angle corresponding to the gear.

5. 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 method for calculating the sag stress of an overhead line by using a correction coefficient state equation as described in any one of claims 1 to 2 is implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for calculating the sag stress of an overhead line by using a correction coefficient state equation as described in any one of claims 1 to 2 is implemented.

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