Multi-gear continuous rapid wire tightening method for overhead transmission line

Abstract

The invention discloses a multi-gear continuous rapid wire tightening method for an overhead transmission line, which comprises the following steps: calculating a corresponding tension value according to an actually measured sag value of a known observation gear so as to obtain an equivalent tension value, and calculating sag values of other gears according to the equivalent tension value; taking the equivalent tension value and the sag value corresponding to each gear as initial values, substituting the initial values into a tension balance equation set, and performing iterative solution by using a numerical method to obtain an actual tension value and an actual sag value corresponding to each gear; the actual sag value is compared with a design value, abnormal gears are found out, and the abnormal gear farthest from the stringing tower is screened out; solving the optimal tension adjustment amount corresponding to the abnormal gear farthest from the stringing tower by using a gradient descent method; and the process is repeated, the optimal tension adjustment amount corresponding to all the abnormal gears is sequentially calculated from far to near according to the distance to the stringing tower, and stringing adjustment is conducted on all the abnormal gears till the actual tension values and the actual sag values of all the gears meet the design requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of overhead line adjustment, and in particular relates to a multi-stage continuous rapid line tightening method for overhead power transmission lines. Background Art

[0002] Wire tightening refers to the process of applying a certain tension during the installation and maintenance of overhead transmission lines to keep the conductors in an appropriate tension state, so as to ensure the stability and safety of the line, prevent swaying or sagging due to uneven force, and optimize power transmission efficiency, thereby improving overall operational reliability.

[0003] Tightening the line usually requires coordinating the adjustments between multiple gears to achieve uniform tension distribution and a reasonable sag state. Traditional tightening methods usually require coordinating the adjustments between multiple gears to achieve uniform tension distribution and a reasonable sag state. When observing sag, select the middle gear when the tension section is below five gears, select the two gears close to both sides between six and twelve gears, and select three gears in the middle and on both sides when the tension section is above twelve gears, and select the larger gear line; when using sag calculation, you can only increase the number of observation gears, not reduce it, and the operator must strictly follow the order to adjust the sag.

[0004] Specifically, first, tighten the conductor, adjust the distance and observe to ensure that the sag meets the design requirements; second, loosen the conductor and adjust the line again to ensure that the sag is within the required range; finally, tighten the conductor to ensure that the sag near the observation point meets the requirements. In order to improve the quality of line installation, the above process must be repeated during the tightening construction to ensure that the sag is controlled within a reasonable range, but this method is time-consuming, and the repeated climbing of the tower by the operators will bring higher safety risks. Therefore, there is an urgent need for an effective method to predict the impact of one gear sag adjustment on other gears, so as to make the tightening process more efficient and accurate. Summary of the invention

[0005] The invention provides a multi-stage continuous rapid line tightening method for overhead power transmission lines, which solves the technical problems in the prior art such as the need for operators to repeatedly climb towers for debugging, low work efficiency, and high safety risks.

[0006] The technical solution provided by the present invention is: A multi-stage continuous fast line tightening method for overhead power transmission lines comprises the following steps: Step 1: Calculate the corresponding tension value according to the measured sag value of the known observation file, and then obtain the equivalent tension value, and then calculate the sag value of other files according to the equivalent tension value; Step 2: Take the equivalent tension value and sag value corresponding to each gear as the initial value, bring them into the tension balance equation group, use the numerical method to iteratively solve, and obtain the actual tension value and actual sag value corresponding to each gear; Step 3: Compare the actual sag value with the design value, find out the abnormal gear, and select the abnormal gear farthest from the tension tower; Step 4: Use the gradient descent method to find the optimal tension adjustment corresponding to the abnormal gear farthest from the take-up tower; Step 5. Repeat steps 3 and 4. Calculate the optimal tension adjustment values ​​for all abnormal gears in order from far to near according to the distance from the tensioning tower, and adjust the tension for all abnormal gears until the actual tension values ​​and actual sag values ​​of all gears meet the design requirements.

[0007] Further, the numerical method comprises the following steps: The sag value and equivalent tension value of each gear are , , taking this as the initial value, the actual sag value and actual tension value are , , i represents the i-th file; Step Ⅰ: Substitute the initial value into the tension balance equation system; Step II: Construct the Jacobian matrix J. and Find the partial derivative and update the variables using the following equation, in, , Represents the current value of the tension balance equations; Step III: Calculate the current value of the Jacobian matrix J and the tension balance equations , and then by solving the linear equation To update each variable; Step IV: Calculate the updated value of the tension balance equations , check whether the convergence condition is met. If converged, stop the iteration and get the actual sag value and actual tension value corresponding to each gear; Otherwise, return to step II for the next iteration.

[0008] Further, the equivalent tension is calculated using the following equation: And the corresponding sag values ​​of other gears , in, Indicates the length corresponding to the i-th file, Indicates the tension value of known observation level i.

[0009] Furthermore, according to the measured sag value of the known observation file , use the following formula to calculate the tension value of the known observation file .

[0010] Furthermore, if it is known that the observed level is between six and twelve, select the two levels close to the two sides. When it is above twelve, select three levels in the middle and on both sides and choose the larger level.

[0011] Furthermore, when using the gradient descent method to solve the optimal tension adjustment, the abnormal gear farthest from the tension tower is denoted as k. First, the actual tension values ​​corresponding to each gear are calculated. , actual sag value As an initial value, the tension adjustment amount The initial value is ,in, Indicates the target tension value, Represents the current tension value, using the chain rule to calculate the gradient , and then according to the gradient descent formula Update the tension value of the current gear, then update the corresponding sag value, and then update the current tension value and current sag value of other gears. Then use the updated current tension value and current sag value as the initial value, repeat the above process until the objective function converges, and calculate the optimal tension adjustment amount of the abnormal gear farthest from the tensioning tower.

[0012] Further, the steps of solving the optimal tension adjustment amount using the gradient descent method are as follows: Step 1: Set the input parameters: the actual tension value corresponding to each gear , Actual sag value As the initial value, set the learning rate α=0.1 and the tension adjustment amount The initial value is , set the number of iterations N = 1000, and the convergence threshold , by and is the constraint condition, among which, , is the design value of sag; Step ii: Adjust the amount according to the current tension Calculate the corresponding current tension value, calculate the current tension values ​​of other gears, and then calculate the corresponding current sag value ; Step iii: Calculate the gradient using the chain rule ; Step IV: updating the current tension adjustment amount according to the gradient descent formula; Step V: Repeat Step II to Step IV until the objective function converges or the number of iterations is reached, and record the result. for .

[0013] Further, the chain rule is used to calculate the gradient When we first set the objective function , in, Indicates the target sag value, Indicates the current sag value; In the objective function , for each Taking partial derivatives we get: Construct the catenary equation: Take the partial derivative of the catenary equation: The gradient is calculated using the following formula: , .

[0014] Further, in step ii, the current tension value corresponding to the gear farthest from the tension tower is calculated using the following formula: ; Then use the following formula to calculate the current tension value of other gears , : The tension adjustment amount of the kth gear; :kth Initial tension value of gear n; :kth The tension value after adjustment in gear n; : Tension transmission coefficient, ; E: elastic modulus of the wire; A: cross-sectional area of ​​the wire; : The length of the file; Finally, the corresponding current sag value is calculated based on the current tension value of each gear. .

[0015] Furthermore, in step three, if the actual sag value is not within the range specified by the design value, the gear is determined to be an abnormal gear.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention anticipates adopting an optimized tightening strategy, by observing the sag value of the observation gear required in the tension section, predicting the tension value and sag value of other continuous multiple gears, thereby calculating the optimal tightening amount for each gear, and improving the tightening efficiency of multi-gear continuous tightening construction of overhead transmission lines.

[0017] Firstly, the line tightening method of the present invention will improve the response speed of the system, so that when a fast line tightening operation is required, the status of other levels can be quickly evaluated and adjusted to ensure the balance and stability of the overall line.

[0018] Secondly, combined with the flexible coupling mechanism, it ensures that the sag changes at each level of the power line are minimized during the rapid tightening process, which will help reduce the impact of adjusting one level on other levels and reduce the number of tightening times.

[0019] In addition, through the application of intelligent optimization algorithms, the system can automatically calculate the optimal tension adjustment amount during operation, so that the adjustment can reach the optimal operating state. This adjustment capability will significantly reduce the operator's repeated up and down tower tightening, thereby improving maintenance efficiency and operator safety.

[0020] Finally, with the efficiency and accuracy of this method, it will provide a new reference for the design and management of power systems, promote the intelligent and automated development of power engineering, and enhance market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall process of an embodiment of the present invention; Figure 2 A schematic diagram of a flow chart of an embodiment of the present invention using a numerical method to perform an iterative solution to obtain actual tension values ​​and actual sag values ​​corresponding to each gear; Figure 3 It is a schematic diagram of the flow chart of the gradient descent method of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and drawings specifically illustrate a bolt fastening device for a high-voltage transmission line tower of the present invention. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0023] In this embodiment, a multi-stage continuous fast line tightening method for overhead power transmission lines is provided. Figure 1 As shown, the sag values ​​of other gears are calculated through the sag of the known gear, and the mathematical model and empirical formula are used to predict the impact of adjusting the sag value of the observed gear on the sag of other gears, so as to find the optimal tightening amount, that is, the optimal tension adjustment value, and simplify the adjustment process.

[0024] The details are as follows: Step 1: Calculate the corresponding tension value based on the measured sag value of the known observation file, and then obtain the equivalent tension value, and then calculate the sag values ​​of other files based on the equivalent tension value.

[0025] S1.1. Measure the sag value of the known observation section: In the overhead transmission line, select the section farthest from the tight end and use the measuring tool to accurately measure the actual sag value of the section. , it should be noted that between the sixth and twelfth gears, choose the two gears close to the sides ( )、( ), when the gear is above 12, select three gears in the middle and on both sides ( )、( )、( ) Select a larger span line. When using sag calculation, you can only increase the number of observation spans, not reduce it.

[0026] S1.2. Calculate the tension value of the known observation file: According to the weight of the unit length of the wire of the known file And file length , use the following formula to calculate the tension value of the known observation file : When the conductor span is greater than 200 meters or when the conductor sag is greater than 1 / 10 of the conductor length, the catenary formula is used to calculate the tension: The tension value is subsequently calculated. For the sake of simplicity, only formula (1) can be used to calculate the tension value.

[0027] S1.3. When the conductor material and unit weight are the same, the equivalent tension can be obtained by combining the equivalent file method with iterative calculation. : According to the known gear and the known gear tension, first get the equivalent tension value : S1.4. Using equivalent tension and length of each file , preliminarily calculate the sag value of other gears : Step 2: Use the equivalent tension value corresponding to each gear and sag value As the initial value, it is substituted into the tension balance equation group, and the numerical method is used to iteratively solve it to obtain the actual tension value and actual sag value corresponding to each gear; like Figure 2 As shown, the sag value and equivalent tension value of each gear are , , taking this as the initial value, the actual sag value and actual tension value are , , i represents the i-th file; Step Ⅰ: Substitute the initial value into the tension balance equation system; Step II: Construct the Jacobian matrix J. and Find the partial derivative and update the variables using the following equation, in, , Represents the current value of the tension balance equations; Step III: Calculate the current value of the Jacobian matrix J and the tension balance equations , and then by solving the linear equation To update each variable; Step IV: Calculate the updated value of the tension balance equations , check whether the convergence condition is met. If converged, stop the iteration and get the actual sag value and actual tension value corresponding to each gear; Otherwise, return to step II for the next iteration.

[0028] After multiple iterations, the actual tension value corresponding to each gear is finally obtained. and actual sag value , the value obtained at this time can accurately reflect the actual sag distribution of the gear.

[0029] Step 3: The actual sag value of each gear Compare with the corresponding design value, find out the abnormal gear, and select the abnormal gear farthest from the tensioning tower.

[0030] Step 4: Use the gradient descent method to find the optimal tension adjustment corresponding to the abnormal gear farthest from the tension tower, such as Figure 3 As shown, first take the actual tension value corresponding to each gear , Actual sag value As initial value, calculate the gradient using the chain rule , and then according to the gradient descent formula Update the tension value of the current gear, then update the sag value, and then update the current tension value and current sag value of other gears, and then use the updated tension value and sag value as the initial value, repeat the above process until the objective function converges, and record the result of this time. for .

[0031] The details are as follows: S4.1. Input parameters: actual tension values ​​corresponding to each gear , actual sag value As the initial value, set the learning rate α=0.1 and the tension adjustment amount The initial value is , where k represents the abnormal gear farthest from the tension tower, and the target tension value By the target sag value By formula (1), we can get: The current tension value is the actual tension value of the kth gear. Set the number of iterations N=1000, which can be gradually increased to 5000 when it does not converge, and the convergence threshold , at this time, the convergence fully meets the tight line accuracy requirements; by and is a constraint condition, where , is the design value of sag; The safe range of tension is determined by the maximum tensile strength of the conductor material, and the safe range of sag is determined by the region and the strength of the conductor material.

[0032] S4.2, adjust the amount according to the current tension Calculate the corresponding current tension value, calculate the current tension values ​​of other gears, and then calculate the corresponding current sag value .

[0033] The tension value of this gear k after the tension changes: After the change, the current tension value calculation method of other gears is: : The tension adjustment amount of the kth gear; :kth Current tension value of gear n; :kth The tension value after adjustment in gear n; : Tension transmission coefficient, E: elastic modulus of the conductor; A: is the cross-sectional area of ​​the conductor; : is the length of the file; Update the current sag value according to the calculated current tension value of each gear: S4.3. Computing the gradient using the chain rule ; Set the objective function as follows: in, Indicates the target sag value, Indicates the current sag value; In the objective function , for each Taking partial derivatives we get: Construct the catenary equation: Find the partial derivative of the catenary equation: Compute the gradient using the chain rule To calculate the objective function Tension value We use the chain rule to multiply the partial derivative of sag with respect to tension and the partial derivative of the objective function with respect to sag: S4.4. Update the tension adjustment according to the gradient descent formula S4.5. Repeat S4.2 to S4.4 until the objective function converges or the number of iterations is reached, and record the result. for .

[0034] Step 5. Repeat steps 3 and 4. Calculate the optimal tension adjustment values ​​for all abnormal gears in order from far to near according to the distance from the tensioning tower, and adjust the tension for all abnormal gears until the actual tension values ​​and actual sag values ​​of all gears meet the design requirements.

[0035] The above-mentioned implementation modes are preferred cases of the present invention and are not used to limit the protection scope of the present invention. Various deformations or modifications that can be made by ordinary technicians in this field without creative work within the scope of the attached claims are still within the protection scope of this patent.

Claims

1. A multi-stage continuous rapid line tightening method for overhead power transmission lines, characterized in that The following steps are involved: Step 1: Calculate the corresponding tension value according to the measured sag value of the known observation file, and then obtain the equivalent tension value, and then calculate the sag value of other files according to the equivalent tension value; Step 2: Take the equivalent tension value and sag value corresponding to each gear as the initial value, bring them into the tension balance equation group, use the numerical method to iteratively solve, and obtain the actual tension value and actual sag value corresponding to each gear; Step 3: Compare the actual sag value with the design value, find out the abnormal gear, and select the abnormal gear farthest from the tension tower; Step 4: Use the gradient descent method to find the optimal tension adjustment corresponding to the abnormal gear farthest from the take-up tower; Step 5. Repeat steps 3 and 4. Calculate the optimal tension adjustment values ​​for all abnormal gears in order from far to near according to the distance from the tensioning tower, and adjust the tension for all abnormal gears until the actual tension values ​​and actual sag values ​​of all gears meet the design requirements.

2. The multi-stage continuous fast wire tightening method for overhead power transmission lines according to claim 1, characterized in that The numerical method comprises the following steps: The sag value and equivalent tension value of each gear are , , taking this as the initial value, the actual sag value and actual tension value are , , i represents the i-th file; Step Ⅰ: Substitute the initial value into the tension balance equation system; in, Indicates the length corresponding to the i-th file, Indicates the weight of the wire per unit length, Step II: Construct the Jacobian matrix J. and Find the partial derivative and update the variables using the following equation, in, , Represents the current value of the tension balance equations; Step III: Calculate the current value of the Jacobian matrix J and the tension balance equations , and then by solving the linear equation To update each variable; Step IV: Calculate the updated value of the tension balance equations , check whether the convergence condition is met. If converged, stop the iteration and get the actual sag value and actual tension value corresponding to each gear; Otherwise, return to step II for the next iteration.

3. The multi-stage continuous fast wire tightening method for overhead power transmission lines according to claim 2, characterized in that: Calculate the equivalent tension using the following equation: And the corresponding sag values ​​of other gears , in, Indicates the length corresponding to the i-th file, Indicates the tension value of the known observation file i, Indicates the weight of the wire per unit length.

4. The multi-stage continuous rapid line tightening method for overhead power transmission lines according to claim 3, characterized in that: According to the measured sag value of the known observation file , use the following formula to calculate the tension value of the known observation file 。 5. The multi-stage continuous rapid line tightening method for overhead power transmission lines according to claim 4, characterized in that: If the observation level is known to be between six and twelve, choose the two levels close to the sides. When it is above twelve, choose three levels in the middle and on both sides and choose the larger level.

6. The multi-stage continuous rapid line tightening method for overhead power transmission lines according to claim 1, characterized in that: When using the gradient descent method to solve the optimal tension adjustment, the abnormal gear farthest from the tension tower is recorded as k. First, the actual tension value corresponding to each gear is , actual sag value As an initial value, the tension adjustment amount The initial value is ,in, Indicates the target tension value, Represents the current tension value, using the chain rule to calculate the gradient , and then according to the gradient descent formula Update the tension value of the current gear, then update the corresponding sag value, and then update the current tension value and current sag value of other gears. Then use the updated current tension value and current sag value as the initial value, repeat the above process until the objective function converges, and calculate the optimal tension adjustment amount of the abnormal gear farthest from the tensioning tower.

7. The multi-stage continuous fast wire tightening method for overhead power transmission lines according to claim 6, characterized in that The steps for solving the optimal tension adjustment using the gradient descent method are as follows: Step 1: Set the input parameters: the actual tension value corresponding to each gear , actual sag value As the initial value, set the learning rate α=0.1 and the tension adjustment amount The initial value is , set the number of iterations N = 1000, and the convergence threshold , by and is the constraint condition, among which, , is the design value of sag; Step ii: Adjust the amount according to the current tension Calculate the corresponding current tension value, calculate the current tension values ​​of other gears, and then calculate the corresponding current sag value ; Step iii: Calculate the gradient using the chain rule ; Step IV: updating the current tension adjustment amount according to the gradient descent formula; Step V: Repeat Step II to Step IV until the objective function converges or the number of iterations is reached, and record the result. for .

8. The multi-stage continuous rapid line tightening method for overhead power transmission lines according to claim 7, characterized in that: Compute the gradient using the chain rule When we first set the objective function , in, Indicates the target sag value, Indicates the current sag value; In the objective function , for each Taking partial derivatives we get: Construct the catenary equation: Take the partial derivative of the catenary equation: The gradient is calculated using the following formula: , 。 9. The multi-stage continuous rapid line tightening method for overhead power transmission lines according to claim 7, characterized in that: In step ii, the current tension value corresponding to the gear farthest from the tension tower is calculated using the following formula: ; Then use the following formula to calculate the current tension value of other gears , : The tension adjustment amount of the kth gear; :kth Initial tension value of gear n; :kth The tension value after adjustment in gear n; : Tension transmission coefficient, ; E: elastic modulus of the wire; A: cross-sectional area of ​​the wire; : The length of the file; Finally, the corresponding current sag value is calculated based on the current tension value of each gear. 。 10. The multi-stage continuous fast wire tightening method for overhead power transmission lines according to claim 1, characterized in that: In the step three, if the actual sag value is not within the range specified by the design value, the gear is determined to be an abnormal gear.

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