CN-117392817-B - Power transmission line deicing jump risk assessment method under strong wind effect

CN117392817BCN 117392817 BCN117392817 BCN 117392817BCN-117392817-B

Abstract

The invention discloses a method for evaluating the ice-removing jump risk of a power transmission line under the action of strong wind, which comprises the steps of 1) collecting relevant information of the power transmission line, 2) establishing a static model and expanding to obtain a wire-insulator finite element model, 3) constructing a wire-insulator-spacer finite element model, 4) numerically simulating motion change tracks of initial positions of all parts of the power transmission line under the action of strong wind in the ice-removing process compared with the parts without the action of ice-wind on the wire-insulator finite element model in the step 2, 5) judging the ice-removing process inhibiting effect of the spacer on a three-phase power transmission line, and 6) setting a safe operation displacement threshold value of the three-phase line and carrying out real-time grading early warning. The method can be applied to the safety state evaluation of the power transmission line in scenes such as different gear distances, height differences, earth lead models, different ice removal rates, ice coating thickness, different wind speeds and the like, and provides scientific basis for risk evaluation and early warning work.

Inventors

DONG XINSHENG
LI MENG
Zhao Sanguan
YANG YANG
WANG HONGXIA
MA SHUYANG

Assignees

国网新疆电力有限公司电力科学研究院

Dates

Publication Date: 20260512
Application Date: 20231012

Claims (4)

1. The power transmission line deicing jump risk assessment method under the action of strong wind is characterized by comprising the following steps of: step1, collecting relevant information of a power transmission line; Step 2, establishing a static model, and expanding to obtain a wire-insulator finite element model, wherein the specific process is as follows: 2.1 Determining the structure of each part on the power transmission line according to the related information acquired in the step 1, and selecting the type of the analog unit; establishing an integral coordinate system, setting a z-axis as a vertical direction of a transmission wire, setting an x-axis as a horizontal direction along the wire direction, and establishing a static model of each part of structure according to wire parameters, insulator string parameters, hardware parameters, icing parameters, crosswind parameters and constraint parameters of wire-insulator hinging of the transmission wire; 2.2 Taking the influence of dead weight on the wire into consideration, and in nonlinear finite element software, adopting a direct iteration method to perform numerical calculation of the initial configuration of the wire; Firstly, according to the actual material properties and the real constants, loading is applied, nonlinear statics analysis is carried out, convergence conditions are set, the finite element model is updated continuously, the conditions are met, namely, iteration is pushed out, the obtained model is the initial model of the lead, and the model is called as a lead-insulator finite element model at the moment; step 3, constructing a finite element model of a wire-insulator-spacer, wherein the specific process is as follows: The practical line usually adopts the addition of a spacer to inhibit the ice-removing bouncing effect of a wire, the wire-insulator finite element model obtained in the step 2 is supported, and the partial double-loop type overhead line of the practical engineering is considered to adopt the addition of the spacer between two lines, so that the spacer is simulated by adopting units which are completely the same as the initial strain, the elastic modulus and the hardness of the power transmission line but different in sectional area, the wire, the spacer and the insulator string model of the power transmission line are respectively built, and all parts are connected through d command streams, so that the wire-insulator-spacer finite element model is obtained; step 4, on the finite element model of the wire-insulator in the step 2, numerically simulating motion change tracks of initial positions of all parts of the power transmission line under the action of strong wind in the ice removing process compared with the initial positions of all parts under the action of no ice-wind; Step 5, judging the ice removing process inhibition effect of the spacer on the three-phase transmission line; And 6, setting a safe operation displacement threshold value of the three-phase line, and performing real-time grading early warning.
2. The method for evaluating the risk of ice-breaking and jumping of a power transmission line under the action of strong wind according to claim 1, wherein in step 4, the specific process is as follows: Setting response parameters including wind speed, wind attack angle, ice coating thickness and ice removal rate; the simulation result is that in the deicing jumping process, the positions of all the partial structures of the transmission line are compared with the displacement difference time history change rule of the dead weight shape finding position of the lead without ice-wind condition; The operation process comprises the steps of opening a large deformation, stress tempering and time integration effect switch, adopting a transient dynamics analysis method and a complete method, assuming that uniform deicing occurs to a deicing gear wire in a certain period, adopting a load removing mode to realize deicing operation at each part of nodes, determining a damping coefficient, determining the final moment of power response calculation according to the vibration process requirement after deicing, The basic equation followed is: (1) In the formula (1), M represents a mass matrix, C represents a damping matrix, K represents a stiffness matrix, and F represents a load array; Representing an acceleration vector; representing a velocity vector; Representing a displacement vector; the analysis process of the dynamic response adopted in the step is as follows: 4.1 Carrying out statics analysis under the dead weight of the lead, namely carrying out lead shape finding analysis, and determining that the deformed shape under the dead weight is the same as the actual shape-catenary shape; 4.2 Applying ice coating load on the basis of the step 4.1), and carrying out statics analysis without considering the dynamic actions of the icing process and the ice coating load; 4.3 The final stabilization time is determined according to the requirement after the free vibration process of complete de-icing; 4.4 Strong wind working conditions under different conditions are set, the deicing process simulation of the power transmission line under the complex conditions is carried out, the deicing power response characteristics are obtained, the deicing power response characteristics are analyzed, the result data of the deicing power response characteristics of the power transmission line are derived, The result data comprises that the difference value result between the position of each node and the self-weight shape finding initial position without ice-wind action is taken as displacement change, the tension change of each insulator string is carried out, and the difference value result between the side tension of the ice removing gear and the side tension is unbalanced dynamic tension change; 4.5 Comparing the space displacement of the wire when the spacing rod is additionally arranged and the spacing rod is not arranged under the conditions of different wind speeds and wind attack angles, and analyzing the inhibiting effect of the spacing rod on the wire ice-removing bouncing under the action of strong wind; 4.6 The method comprises the steps of analyzing the suppression effect of wire deicing bouncing, namely, bouncing displacement of the wire, and bouncing amplitude of the wire, and then, deriving a time displacement course curve of the transmission line with and without a spacer under the conditions of different wind speeds and wind attack angles, and comparing bouncing numerical variation conditions of all space dimensions.
3. The method for evaluating the risk of ice-breaking and jumping of the power transmission line under the action of strong wind according to claim 1, wherein in step 5, the specific process is as follows: Aiming at the finite element model of the wire-insulator without the spacer in the step 2 and the finite element model of the wire-insulator-spacer with the spacer in the step 3, the deicing test is carried out under the strong wind condition, the bouncing distance of the deicing end point in the longitudinal direction and the swinging distance in the transverse direction are used for judging the deicing process inhibition effect of the spacer on the three-phase transmission line, Determining that the effect of adding the spacing bars at 1/2 of the length direction of the wire is optimal by simulating whether the spacing bars between the two phases are added or not, wherein the more the adding quantity is, the more stable the phase intervals of the power transmission line are; The spacer is additionally arranged under the windy condition, so that the displacement of the wire in the horizontal direction can be effectively restrained, and the effect is enhanced along with the increase of the wind speed.
4. The method for evaluating the risk of ice-breaking and jumping of the power transmission line under the action of strong wind according to claim 1, wherein in step 6, the specific process is as follows: and setting a safe operation displacement threshold value of the three-phase line according to the national standard and the simulation result, and indicating the risk of electrical accidents of the line and early warning in time when the operation displacement exceeds the threshold value.

Description

Power transmission line deicing jump risk assessment method under strong wind effect Technical Field The invention belongs to the technical field of power system safety, and relates to a power transmission line deicing jump risk assessment method under the action of strong wind. Background At present, research work aiming at risk assessment of electric accidents of a power transmission line mainly aims at unbalanced dynamic tension, stress change conditions of all nodes under different simulation response conditions of the power transmission line are explored, when the tension of the power transmission line is changed strongly, insulator deflection is easy to cause, insulator and hardware fittings can be damaged seriously, great influence is caused on a power transmission tower, and a power transmission wire breakage problem can also occur. When the power transmission line is subjected to ice-removing jumping, the distance between lines of the power transmission line is obviously changed, and when the line distance is too small, a discharge accident can occur. Particularly, under the arrangement structure of part of the power transmission lines, the separation distance can be greatly reduced by ice-removing jumping in strong wind weather. Therefore, in order to cope with the damage caused by the ice removal of the power transmission line under the action of strong wind, the safety and stability of electricity consumption are ensured, the state evaluation is carried out on the risk of the line in ice removal, and the timely early warning of the discharge accident caused by the reduction of the distance is facilitated. Disclosure of Invention The invention aims to provide a power transmission line deicing jump risk assessment method under the action of strong wind, which solves the problems that the state assessment mode of risk in line deicing is not scientific, the assessment effect is not ideal, and the assessment result cannot meet the actual application in the prior art. The technical scheme adopted by the invention is that the method for evaluating the risk of ice-removing jump of the power transmission line under the action of strong wind is implemented according to the following steps: step1, collecting relevant information of a power transmission line; Step 2, establishing a static model, and expanding to obtain a wire-insulator finite element model; step 3, constructing a finite element model of a wire-insulator-spacer; step 4, on the finite element model of the wire-insulator in the step 2, numerically simulating motion change tracks of initial positions of all parts of the power transmission line under the action of strong wind in the ice removing process compared with the initial positions of all parts under the action of no ice-wind; Step 5, judging the ice removing process inhibition effect of the spacer on the three-phase transmission line; And 6, setting a safe operation displacement threshold value of the three-phase line, and performing real-time grading early warning. The method has the advantages that 1) the method is used for acquiring meteorological parameters of the structure, design and operation environment of the power transmission line in actual engineering, establishing a finite element model of a tower line coupling system of the power transmission line based on the actual parameters, and determining the safety state of the tower line coupling system according to the horizontal initial tension. 2) According to the method, aiming at the characteristic analysis of the deicing dynamic response of the power transmission line under the action of strong wind, the phase-to-phase distance change among the parts of the power transmission line is analyzed through numerical simulation, the running safety distance is set, and when the simulation distance is smaller than the safety running distance, the accident risk of the power transmission line is indicated. 3) The method can be applied to the safety state evaluation of the power transmission line in scenes such as different gear distances, height differences, wire (ground) models, different ice removal rates, ice coating thickness, different wind speeds and the like, and provides scientific basis for risk evaluation and early warning work. Drawings FIG. 1 is an overall flow diagram of the method of the present invention; FIG. 2a is a partial enlarged view of a model of the method of the present invention based on an actual three-phase transmission line construction; fig. 2b is a schematic diagram of the spacing distance between each phase of wires based on an actual three-phase transmission line construction model in the method of the present invention under the ice-coating condition; fig. 3a is a finite element model of a three-phase line conductor-insulator coupling system of step2 in the method of the present invention; fig. 3b is a finite element model of a three-phase line conductor-spacer-insulator coupling system of step 3 in the m