Method for evaluating ice shedding and jumping risk of power transmission line under strong wind

Abstract

The application discloses a kind of transmission line ice shedding jump risk assessment methods under strong wind action, steps include:1) collection relevant information of transmission line;2) establish static model, then expansion obtains "wire-insulator" finite element model;3) construct "wire-insulator-spacer" finite element model;4) on the "wire-insulator" finite element model of step 2, numerical simulation under strong wind action, compared with each part initial position of each part in ice shedding process of transmission line, the motion change trajectory when wind effect is not ice;5) judge the inhibition effect of spacer to the ice shedding process of three-phase transmission line;6) set the safe operation displacement threshold of three-phase line, real-time grading early warning.The method of the application can be applied to the safety state assessment of transmission line in different span, height difference, wire (ground) line model, different ice shedding rate, ice thickness and different wind speed and other scenes, to provide scientific basis for risk assessment and early warning work.

Description

Technical Field

[0001] This invention belongs to the field of power system safety technology and relates to a method for assessing the risk of transmission line de-icing and jumping under strong winds. Background Technology

[0002] Currently, research on risk assessment for electrical accidents in transmission lines mainly focuses on unbalanced dynamic tension, exploring the stress changes at various nodes under different simulated response conditions of transmission lines. When the tension of the transmission line changes drastically, it can easily lead to insulator deflection, and in severe cases, it can cause damage to insulators and fittings, significantly impacting transmission towers and causing transmission conductor breakage.

[0003] When a transmission line experiences de-icing and skipping, the inter-line distance changes significantly. If the distance becomes too small, a discharge accident may occur. Particularly in the layout of some transmission lines, de-icing during strong winds can drastically reduce the phase-to-phase distance. Therefore, to address the hazards caused by de-icing of transmission lines under strong winds and ensure safe and stable power supply, a condition assessment of the risks during line de-icing is crucial for timely early warning of discharge accidents caused by reduced phase-to-phase distance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for assessing the risk of power transmission line de-icing and jumping under strong winds, which solves the problems of unscientific state assessment methods, unsatisfactory assessment results, and inability to meet the requirements of practical applications in the existing technology for assessing the risk of line de-icing.

[0005] The technical solution adopted in this invention is a method for assessing the risk of power transmission line de-icing and jumping under strong winds, which is implemented according to the following steps:

[0006] Step 1: Collect relevant information about the transmission lines;

[0007] Step 2: Establish a static model, and then expand it to obtain a "conductor-insulator" finite element model;

[0008] Step 3: Construct a finite element model of the "conductor-insulator-spacer" structure;

[0009] Step 4: On the “conductor-insulator” finite element model in Step 2, numerically simulate the motion trajectory of each part of the transmission line under strong wind during the de-icing process, compared with the initial position trajectory when there is no ice-wind effect.

[0010] Step 5: Determine the effect of the spacer bar on the de-icing process of the three-phase transmission line;

[0011] Step 6: Set the safe operating displacement threshold for the three-phase line and issue real-time graded early warnings.

[0012] The beneficial effects of this invention are: 1) By obtaining meteorological parameters of the structure, design, and operating environment of transmission lines in actual engineering projects, a finite element model of the tower-line coupling system of the transmission line is established based on the actual parameters, and the safety status of the tower-line coupling system is determined according to the initial horizontal tension. 2) The method of this invention analyzes the de-icing dynamic response characteristics of transmission lines under strong winds, numerically simulates the changes in phase-to-phase distances between different parts of the transmission line, sets a safe operating distance, and indicates that there is a risk of accident in the operation of the transmission line when the simulated distance is less than the safe operating distance. 3) The method of this invention can be applied to the safety status assessment of transmission lines in scenarios with different spans, elevation differences, conductor (ground) wire types, different de-icing rates, ice thicknesses, and different wind speeds, providing a scientific basis for risk assessment and early warning work. Attached Figure Description

[0013] Figure 1 This is a simplified flowchart of the overall process of the method of the present invention;

[0014] Figure 2a This is a partially enlarged view of the model constructed based on an actual three-phase transmission line, which is the basis of the method of this invention.

[0015] Figure 2b This is a schematic diagram of the spacing between conductors of each phase under conditions of icing and non-icing, based on a model of an actual three-phase transmission line constructed according to the method of the present invention.

[0016] Figure 3a This is the finite element model of the three-phase line conductor-insulator coupling system in step 2 of the method of this invention;

[0017] Figure 3b This is the finite element model of the three-phase line conductor-spacer-insulator coupling system in step 3 of the method of the present invention;

[0018] Figure 3c This is the finite element model of the two-phase line conductor-spacer-insulator coupling system in step 3 of the method of the present invention;

[0019] Figure 4a Step 4 of the method of the present invention is the time history curve of the midpoint of the de-icing section of the transmission line without spacers in the spatial scale under the working condition of Example 2.

[0020] Figure 4b Step 4 of the method of the present invention is the time history curve of the midpoint of the de-icing section of the transmission line with spacers installed under the working condition of Example 2 in terms of spatial scale.

[0021] Figure 5a This is step 6 of the method of the present invention, a schematic diagram of the minimum phase distance change during de-icing under windless conditions in Example 3;

[0022] Figure 5bThis is step 6 of the method of the present invention, a schematic diagram of the minimum phase distance change during de-icing under strong wind conditions in Example 3. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] Reference Figure 1 The method for assessing the risk of power transmission line de-icing and jumping under strong winds according to the present invention is implemented according to the following steps:

[0025] Step 1: Collect relevant information about the transmission lines.

[0026] The relevant information includes the structural and design parameters of each part, as well as the environmental and meteorological conditions during operation.

[0027] Step 2: Establish a static model, and then expand it to obtain a "conductor-insulator" finite element model.

[0028] 2.1) Based on the relevant information collected in step 1, determine the structure of each part of the transmission line and select the simulation unit type;

[0029] Establish an overall coordinate system, with the z-axis set to the vertical direction of the transmission line, the x-axis set to the direction along the transmission line, and the y-axis set to the horizontal direction. Based on the parameters of the transmission line conductor, insulator string, fittings, icing, crosswind, and constraint parameters of the conductor-insulator hinge, establish static models of each part of the structure. Then, interconnect the static models of each part of the structure to obtain the overall static model of the transmission line.

[0030] 2.2) Considering the influence of the conductor's own weight, the initial configuration of the conductor is numerically calculated using a direct iteration method in nonlinear finite element software.

[0031] First, based on the actual material properties and real constants, loads are applied, and nonlinear static analysis is performed. Convergence conditions are set, and the finite element model is continuously updated. Once the conditions are met, the iteration is terminated, and the resulting model is the initial model of the conductor, which is called the "conductor-insulator" finite element model. Figure 3a As shown.

[0032] Step 3: Construct a finite element model of the "conductor-insulator-spacer" system.

[0033] Since actual lines typically use spacers to suppress the ice-shedding bounce of conductors, the finite element model of the "conductor-insulator" obtained in step 2 (see...) is used as a basis for this approach. Figure 3a Furthermore, considering that in actual engineering projects, some double-circuit overhead lines often employ the addition of spacers between the two lines (see...), Figure 3cTherefore, elements with the same initial strain, elastic modulus, and hardness as the transmission line, but with different cross-sectional areas, were used to simulate the spacer. Models of the transmission line conductors, spacers, and insulator strings were built separately, and the various parts were connected using the d-command flow to obtain a "conductor-insulator-spacer" finite element model. The effect of adding spacers is shown in the image. Figure 3b .

[0034] Furthermore, the specific steps for establishing the finite element models of the "conductor-insulator" and "conductor-insulator-spacer" coupled systems of the three-phase transmission line in steps 2 and 3 are summarized as follows:

[0035] 3.1) Set up the conductor element. Select the LINK10 rod element to simulate the conductor and set its relevant options such as elastic modulus, Poisson's ratio, initial strain and density.

[0036] 3.2) Traverse modeling: Based on the actual engineering situation, key points are set, and a straight traverse model is established;

[0037] 3.3) Mesh generation. The density of the mesh affects the calculation accuracy and also places high demands on the computer's performance. In this step, the mesh is generated at 1m per cell.

[0038] 3.4) To solve the problem, fully constrain the two suspension points of the conductor, apply the conductor's self-weight load or icing load, set the relevant options for nonlinear solution, and then perform nonlinear static solution.

[0039] 3.5) Set convergence conditions. Usually, the convergence condition is that the error of the horizontal tension at the lowest point is less than 0.001. If the condition is met, the solution is terminated.

[0040] 3.6) Spacer bar element settings: Select the LINK10 bar element to simulate the spacer bar, set the relevant options for this element such as elastic modulus, Poisson's ratio, initial strain and density, and set the cross-sectional area to 8 times that of the conductor;

[0041] 3.7) Spacer modeling: Based on the actual engineering situation, ensure the required number of spacers are applied, reasonably segment the conductor, determine the points where spacers are applied on the double conductor, and connect the two points to connect the spacer model.

[0042] 3.8) Check the post-processing results, such as conductor sag, stress, and line length, to further verify whether the model meets the actual engineering needs.

[0043] In the two finite element models mentioned above, the conductors and spacers are both of type Link 10 rod elements, and the insulator strings are of type Link 8 rod elements. The material parameters include dimensions, strength, elastic modulus, Poisson's ratio, density, and gravitational acceleration. Since torque and bending moment will be generated between the connection nodes, the hinge joint between the conductor and the insulator is set as a hinge support connection, which can achieve free rotation so as to approximate the rigidity of the insulator string model.

[0044] In both of the above finite element models, transmission towers are not included because, during the de-icing response process, the influence of transmission towers on the bounce distance of the transmission line after the ice falls off is negligible.

[0045] Step 4: On the "conductor-insulator" finite element model from Step 2, numerical simulation is performed on the motion trajectories of various parts of the transmission line during the de-icing process under strong wind conditions, compared to the initial positions under no-ice-wind conditions. The specific process is as follows:

[0046] Set response parameters: including wind speed, wind angle of attack, ice thickness, and ice removal rate;

[0047] The simulation results show the time history of the displacement difference between the positions of various parts of the transmission line structure and the self-weight repositioning position of the conductor under ice-free and wind-free conditions during the ice-free jumping process.

[0048] The operation process is as follows: The large deformation, stress hardening, and time integration effect switches are activated; transient dynamic analysis and the complete method are employed, assuming uniform de-icing of the conductor within a certain period; de-icing is achieved at various nodes by unloading; the damping coefficient is determined, and the termination time of the dynamic response calculation is determined based on the vibration process after de-icing.

[0049] The basic equations followed are:

[0050] In equation (1), M represents the mass matrix; C represents the damping matrix; K represents the stiffness matrix; and F represents the load array. Represents the acceleration vector; u represents the velocity vector; u represents the displacement vector.

[0051] The dynamic response analysis process used in this step is as follows:

[0052] 4.1) Perform static analysis of the conductor under its own weight, i.e., conductor form-finding analysis, to determine that the deformed shape under its own weight is the same as the "actual shape - catenary".

[0053] 4.2) Based on step 4.1), apply icing load and perform static analysis, without considering the icing process and the dynamic effects of icing load;

[0054] 4.3) Transient dynamics method is used to study the ice removal process; the subsequent process is the free vibration process of complete ice removal, and the final stabilization time is determined as needed;

[0055] 4.4) Under different strong wind conditions, simulate the de-icing process of transmission lines under complex conditions, obtain the de-icing dynamic response characteristics, analyze the de-icing dynamic response characteristics, and derive the result data of the de-icing dynamic response characteristics of transmission lines.

[0056] The results include: the difference between the position of each node and the initial position of self-weight shaping when there is no ice and wind, which is the displacement change; the tensile force change of each insulator string; and the difference between the tensile force on the ice-removing side and the tensile force on the side, which is the unbalanced dynamic tension change.

[0057] 4.5) Compare the spatial displacement of the conductor with and without spacers under different wind speeds and wind angles of attack, and analyze the effect of spacers on suppressing conductor de-icing and bouncing under strong winds.

[0058] 4.6) The effect of suppressing conductor de-icing bounce is analyzed from two aspects: the bounce displacement of the conductor and the bounce amplitude of the conductor. Then, the time displacement history curves of the transmission line with and without spacers under different wind speeds and wind angles of attack are derived to compare the changes in bounce values ​​in each spatial dimension.

[0059] Step 5: For the finite element models of the "conductor-insulator" without spacers in Step 2 and the "conductor-insulator-spacer" with spacers in Step 3, conduct de-icing tests under strong wind conditions. Determine the effectiveness of the spacers in suppressing the de-icing process of the three-phase transmission line by measuring the bounce distance in the longitudinal direction (vertical direction) and the swing distance in the lateral direction (horizontal direction) at the end of the de-icing stop.

[0060] By simulating the comparison of whether or not spacers are installed between phases, it was determined that installing spacers at 1 / 2 of the conductor length has the best effect; and the more spacers installed, the more stable the phase spacing of the transmission line becomes; when the distance between conductor spans increases, or the distance between phases increases, the spacers will significantly reduce the de-icing bounce displacement of the conductor, suppress the bounce amplitude, and effectively avoid the risk of phase-to-phase discharge.

[0061] Installing spacers in windy conditions can effectively suppress the horizontal displacement of the conductor, and the effect increases with wind speed.

[0062] Step 6: Set the safe operating displacement threshold for the three-phase line and provide real-time tiered early warning.

[0063] Based on national standards and simulation results, a safe operating displacement threshold is set for three-phase lines. When the operating displacement exceeds the threshold, it indicates that there is a risk of electrical accidents in the line and an early warning is issued in a timely manner.

[0064] National standards stipulate that in areas below 1000m altitude, during live-line work, the minimum phase-to-phase gap and span for phase-to-phase switching overvoltage must take into account conductor wind deflection, power frequency voltage, and switching overvoltage. The minimum phase-to-phase gap is measured in meters (m), and the values ​​are shown in Table 1 below.

[0065] Table 1. Permissible Range of Switching Overvoltage

[0066]

[0067]

[0068] The safety threshold for the operation of transmission lines is set as the safe operating distance of the power frequency voltage specified in the national standard. When the distance between any part of two phases of the transmission line is less than this threshold, it is considered that an electrical accident has occurred in the transmission line and is set as a red warning.

[0069] The threshold for potential operational risks of a transmission line is set as half the initial distance between two phases. When the difference in the positional distance between the two phases after the transmission line has de-iced is less than this threshold (i.e., the response situation where the safety threshold < minimum distance between phases < half the initial distance), it indicates that the probability of an electrical accident in the transmission line will increase significantly, and this is set as a yellow warning.

[0070] In particular, the minimum phase-to-phase distance allowed for safe operation of power frequency voltage is often less than the set threshold distance.

[0071] Example 1

[0072] Based on the aforementioned method and steps, the following specific process will be implemented:

[0073] Step 1: Collect information on the structural and design parameters of each part of the transmission line, as well as the environmental meteorological conditions for operation. A detailed enlarged view of a specific section of the transmission line's structure is shown below. Figure 2a The distance between each phase of a three-phase transmission conductor is as follows: Figure 2b Point O represents the initial position of the transmission line under conditions of no ice wind, where it is only affected by its own gravity, and point N represents the vertical descent of the transmission line after it is covered with ice.

[0074] Step 2: Based on the collected information, establish a refined "conductor-insulator" finite element model of the three-phase line coupling system, see... Figure 3a .

[0075] Step 3: Based on the "conductor-insulator" finite element model, by installing different numbers of spacers and considering the different installation positions of the spacers, a refined "conductor-spacer-insulator" finite element model of the three-phase line coupling system is obtained. (See...) Figure 3b ;

[0076] Step 4: On the “conductor-insulator” finite element model in Step 2, the additional load method is used to simulate the icing load, crosswind load, lift load and de-icing load on the transmission line. The self-damping model coefficient is set (with a value of 0.12) to simulate the vibration process of the actual transmission line in the project. Numerical simulation is performed to obtain the time history variation law of the displacement difference between the position of each part of the three-phase transmission line structure and the self-weight form-finding position of the conductor under no-ice-wind conditions during the de-icing jump process.

[0077] Step 5: Apply the same de-icing conditions as in Step 4 to the “conductor-spacer-insulator” finite element model, i.e., the same transmission line icing load, crosswind load, lift load, de-icing load, and self-damping model (with a value of 0.12). Based on the variation law of the conductor's bounce displacement, bounce amplitude, and swing distance, determine the suppression effect of the spacer on the de-icing response process of the transmission line under strong wind.

[0078] Step 6: Set the safe operating displacement threshold for the three-phase line according to national standards and simulation results. When the operating displacement exceeds the threshold, the line is at risk of electrical accident and an early warning will be issued in time.

[0079] It is assumed that when de-icing occurs in the test line, it is always single-phase de-icing while the other two phases remain iced.

[0080] Furthermore, the safe operating threshold for three-phase lines is set as the phase-to-phase distance when the power frequency voltage exceeds the threshold. Operating conditions below this threshold are considered over-limit risk conditions. This type of de-icing method indicates that an electrical accident has occurred in the transmission line.

[0081] Furthermore, according to Figure 2a , Figure 2b The distances between the phases of the three-phase transmission conductor shown are 7m, 7m, and 8m for phases AC, AB, and BC, respectively. After the conductors de-iced due to strong winds, although there was no risk of exceeding the limit, there was a response situation where the safety threshold < minimum phase distance < 1 / 2 of the initial distance. This indicates that the probability of electrical accidents in the transmission line has increased significantly. This type of response condition is called a potential risk condition.

[0082] In particular, since the safe distance threshold allowed for operation under power frequency voltage is often less than that allowed for operation under switching overvoltage, when there is a risk of discharge when the transmission line is operating under switching overvoltage, it may not necessarily have a risk of discharge when operating under power frequency voltage.

[0083] The above-mentioned conductor is model LGJ-630 / 45, the insulator is model FC7P / 146, and the spacer is model FXGB-12-1200. The relevant parameters of the numerical simulation of the conductor, insulator, and spacer are shown in Table 2 below.

[0084] Table 2. Relevant mechanical parameters of the conductors, insulators, and spacers used in Example 1

[0085] parameter LGJ-630 / 45 FC7P / 146 FXGB-12-1200 <![CDATA[Calculate the area (mm 2 )]]> 666.55 - - Outer diameter (mm) 33.60 - - Calculate the breaking force (kN). 148.7 - - Calculate the mass (kg / m). 2.06 - - <![CDATA[Modulus of elasticity (N / mm 2 )]]> 63000 - - <![CDATA[Coefficient of linear expansion (10 -6 / °C)]]> 20.9 - - Poisson's ratio 0.3 0.3 0.3 Length (m) 400m / gear 5m 7m & 8m

[0086] Test wind speed: 10-25 m / s; equivalent ice thickness: 15 mm; de-icing rate: 100%; damping coefficient: 0.12; response time: 0-200 s; conductor length per section: 400 m.

[0087] Example 2

[0088] Referring to the specific method of Example 1, the analysis and simulation of the suppression effect on the de-icing response process of the transmission line under strong wind after adding spacer bars in step 5 were completed.

[0089] Taking a wind angle of attack of 0° and a test wind speed of 10 m / s as an example, the method for installing spacers is as follows: Figure 3b This means that it is installed at a point 1 / 4 of the span of the conductor near the tower.

[0090] The time history curve of the de-icing midpoint of the transmission line without spacers (i.e., without spacers) on a spatial scale is shown in the figure. Figure 4a The time history curve of the de-icing midpoint of the transmission line with added spacers (or with spacers) on a spatial scale is shown in the figure. Figure 4b The right-hand projection shows the longitudinal bounce displacement change at the end of the de-icing section after de-icing, while the lower projection shows the lateral swing displacement change at the end of the de-icing section. It can be seen that the bounce amplitude without spacers is approximately 2.05m [(-0.45)-(-2.8)], while the maximum longitudinal bounce with spacers is approximately 1.1m [(-1.95)-(-3.05)], with a suppression effect of approximately 46% [(1.1-2.05) / 2.05]. A comparison of lateral displacement shows that, under windy conditions, installing spacers reduces the horizontal displacement (z-direction) of the conductor by approximately 20cm. This indicates that installing spacers has a good suppressive effect on the de-icing bounce of transmission lines, significantly reducing the longitudinal bounce amplitude of the conductor and greatly reducing the possibility of accidents after conductor de-icing.

[0091] Example 3

[0092] Following the method described in Example 1, complete the risk assessment and early warning of the de-icing process under strong winds in steps 4 and 6.

[0093] Taking a design wind speed of 0, 10-25 m / s (5 m / s interval) and a wind angle of attack of 0-360° (15° interval) as an example, the de-icing method is single-phase de-icing, while the other two phases remain iced. Specifically, in condition one, phase B de-icing is used; in condition two, phase C de-icing is used; and in condition three, phase A de-icing is used.

[0094] Figure 5a For the possible displacement change of the three-phase de-icing response under no-wind conditions, from Figure 5a It can be seen that when single-phase de-icing occurs, the minimum distance between phases is equal to half of the distance between phases B and C (4 m). At this time, it is always greater than the safe operation threshold of each phase conductor under power frequency voltage, that is, there is no risk of power frequency voltage discharge under no-wind conditions.

[0095] Figure 5b For the possible displacement change of the three-phase de-icing response under strong-wind conditions, due to the influence of the lateral wind at this time, over-limit situations (minimum distance between phases < safety threshold) and possible risk situations (response situation where safety threshold < minimum distance between phases < initial distance) will occur. The results are summarized in Table 3.

[0096] As can be seen from the results in Table 3, the three working conditions are described as follows:

[0097] Select the de-icing response process under the conditions of phase B de-icing, wind speed of 10 m / s, and wind attack angle of \({135}^{\circ}\) in Working Condition 1. The minimum distance between the de-icing sections of phases A and B is less than the safety threshold, and operation discharge occurs, which belongs to the over-limit risk working condition, and a red warning is issued;

[0098] Select the de-icing of phase C, wind speed of 10 m / s, and wind attack angle of \({0}^{\circ}\) in Working Condition 2. The safety threshold < the minimum distance between the de-icing sections of phases A and C < 1 / 2 of the initial distance (3.5 m), and the operation discharge risk is greatly increased, which belongs to the possible risk working condition, and a yellow warning is issued;

[0099] Table 3 summarizes the results of the discharge risk conditions under strong-wind conditions.

[0100]

[0101]

[0102] In addition, select the de-icing of phase A in Working Condition 3. The situation of operation risk in this de-icing method is relatively small, and there is basically no discharge accident when de-icing occurs under various wind attack angles and wind speed of 10 m / s.

Claims

1. A method for assessing the risk of power transmission line de-icing and jumping under strong winds, characterized in that, Follow these steps: Step 1: Collect relevant information about the transmission lines; Step 2: Establish a static model, and then expand it to obtain a "conductor-insulator" finite element model. The specific process is as follows: 2.1) Based on the relevant information collected in step 1, determine the structure of each part of the transmission line and select the simulation unit type; Establish an overall coordinate system, with the z-axis set to the vertical direction of the transmission line, the x-axis set to the direction along the transmission line, and the y-axis set to the horizontal direction. Based on the parameters of the transmission line conductor, insulator string, fittings, icing, crosswind, and constraint parameters of the conductor-insulator hinge, establish static models of each part of the structure. Then, interconnect the static models of each part of the structure to obtain the overall static model of the transmission line. 2.2) Considering the influence of the conductor's own weight, the initial configuration of the conductor is numerically calculated using a direct iteration method in nonlinear finite element software. First, based on the actual material properties and real constants, loads are applied, nonlinear static analysis is performed, convergence conditions are set, and the finite element model is continuously updated. When the conditions are met, the iteration is terminated, and the resulting model is the initial model of the conductor, which is called the "conductor-insulator" finite element model. Step 3: Construct the finite element model of "conductor-insulator-spacer". The specific process is as follows: In actual lines, spacers are usually installed to suppress the de-icing and bouncing effect of the conductors. Based on the "conductor-insulator" finite element model obtained in step 2, and considering that some double-circuit overhead lines in actual engineering often use spacers between the two lines, we use elements with the same initial strain, elastic modulus, and hardness as the transmission line, but with different cross-sectional areas to simulate the spacers. We build the conductor, spacer, and insulator string models of the transmission line respectively, and connect the various parts through the d command flow to obtain the "conductor-insulator-spacer" finite element model. Step 4: On the "conductor-insulator" finite element model in Step 2, numerically simulate the motion trajectory of each part of the transmission line under strong wind during the de-icing process, compared with the initial position trajectory when there is no ice-wind effect. Step 5: Determine the effect of the spacer bar on the de-icing process of the three-phase transmission line; Step 6: Set the safe operating displacement threshold for the three-phase line and issue real-time graded early warnings.

2. The method for assessing the risk of power transmission line de-icing and jumping under strong winds according to claim 1, characterized in that, Step 4, the specific process is as follows: Set response parameters: including wind speed, wind angle of attack, ice thickness, and ice removal rate; The simulation results show the time history of the displacement difference between the positions of various parts of the transmission line structure and the self-weight forming position of the conductor under ice-free and wind-free conditions during the ice-free jumping process. The operation process is as follows: The large deformation, stress hardening, and time integration effect switches are activated; transient dynamic analysis and the complete method are employed, assuming uniform de-icing of the conductor within a certain period; de-icing is achieved at various nodes by unloading; the damping coefficient is determined, and the termination time of the dynamic response calculation is determined based on the vibration process after de-icing. The basic equations followed are: (1) In equation (1), M Represents the mass matrix; C Represents the damping matrix; K Represents the stiffness matrix; F Represents the load array; Represents the acceleration vector; Represents the velocity vector; Represents the displacement vector; The dynamic response analysis process used in this step is as follows: 4.1) Perform static analysis of the conductor under its own weight, i.e., conductor form-finding analysis, to determine that the deformed shape under its own weight is the same as the "actual shape - catenary". 4.2) Based on step 4.1), apply icing load and perform static analysis, without considering the dynamic effects of the icing process and icing load; 4.3) Transient dynamics method is used to study the ice removal process; the subsequent process is a free vibration process of complete ice removal, and the final stabilization time is determined as needed; 4.4) Under different strong wind conditions, simulate the de-icing process of transmission lines under complex conditions, obtain the de-icing dynamic response characteristics, analyze the de-icing dynamic response characteristics, and derive the result data of the de-icing dynamic response characteristics of transmission lines. The results include: the difference between the position of each node and the initial position of self-weight shaping when there is no ice and wind, which is the displacement change; the tensile force change of each insulator string; and the difference between the tensile force on the ice-removing side and the tensile force on the side, which is the unbalanced dynamic tension change. 4.5) Compare the spatial displacement of the conductor with and without spacers under different wind speeds and wind angles of attack, and analyze the effect of spacers on suppressing conductor de-icing and bouncing under strong winds. 4.6) The effect of suppressing conductor de-icing bounce is analyzed from two aspects: the bounce displacement of the conductor and the bounce amplitude of the conductor. Then, the time displacement history curves of the transmission line with and without spacers under different wind speeds and wind angles of attack are derived to compare the changes in bounce values ​​in each spatial dimension.

3. The method for assessing the risk of power transmission line de-icing and jumping under strong winds according to claim 1, characterized in that, Step 5, the specific process is as follows: For the finite element models of the "conductor-insulator" without spacers in step 2 and the "conductor-insulator-spacer" with spacers in step 3, de-icing tests were conducted under strong wind conditions. The longitudinal bounce distance and lateral swing distance at the end of the de-icing stop were measured to determine the effect of the spacers on inhibiting the de-icing process of the three-phase transmission line. By simulating the comparison of whether or not to install spacers between phases, it was determined that installing spacers at 1 / 2 of the conductor length direction has the best effect; and the more spacers installed, the more stable the phase spacing of the transmission line becomes; when the distance between conductor spans increases, or the distance between phases increases, the spacers will significantly reduce the de-icing bounce displacement of the conductor, suppress the bounce amplitude, and effectively avoid the risk of phase-to-phase discharge. Installing spacers in windy conditions can effectively suppress the horizontal displacement of the conductor, and the effect increases with wind speed.

4. The method for assessing the risk of power transmission line de-icing and jumping under strong winds according to claim 1, characterized in that, Step 6 involves the following specific steps: Based on national standards and simulation results, a safe operating displacement threshold is set for three-phase lines. When the operating displacement exceeds the threshold, it indicates that there is a risk of electrical accidents in the line and an early warning is issued in a timely manner.

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