Aging Risk Assessment For Overhead Conductors Based On Fuzzy Logic Considering Cumulative Environmental Effects

With the increasing service time of overhead transmission lines and the influence of environmental factors,the lines have different degrees of aging,which seriously affects the normal operation of transmission lines and is not conducive to the safety of production and power supply.Line aging will lead to broken strands and lines,the tensile strength of the conductor can not bear the actual load,or the line tower can not continue to bear,resulting in the normal operation of the whole line.The existing conductor condition assessment mainly relies on the mechanical model,and rarely considers the actual operating environment of the line,so it is difficult to directly apply to the production operation and maintenance of transmission lines.Therefore,this thesis collects and analyzes the uav inspection data of transmission lines,and fuses mechanical mechanism and fuzzy theory.The fuzzy risk assessment of overhead transmission line based on environmental cumulative effect is studied.It provides theoretical basis for transmission line operation and maintenance and improves transmission line operation safety and power transmission quality.The main research contents and conclusions of this thesis are as follows:（1）Based on the strain calculation model and tensile strength loss calculation model,this thesis presents a time accumulation calculation method based on the operating temperature of transmission line conductors.Comprehensively consider the actual meteorological data and conductor parameters in the area where the line is located to determine the running time of line overload.The loss estimation of conductor tensile strength based on Harvey model is realized.This method can not only evaluate the mechanical properties of conductors,but also provide key performance parameters for the risk assessment model of conductors.（2）A fuzzy logic risk assessment method for transmission lines is proposed.Based on the strain and tensile strength loss of conductor,the relationship between fuzzy inference propositions and conclusions is established,and the fuzzy rule base is generated.The output is the risk level of the current running state of the conductor.The feasibility of the proposed method is verified by using a long-term running line,and the aging risk assessment of transmission lines is realized.（3）Aiming at the influence of environmental cumulative effect on the line tower,the point cloud data of the tower is vectorized.The vectorized model of the tower is introduced into the stress analysis system,and the stress analysis report of the tower is output through ANSYS finite element simulation calculation.The aging risk status is evaluated by the stress ratio of the tower main material and the inclined material.The aging risk assessment of transmission line based on integrated transmission line and tower can be carried out by analyzing the aging stress of transmission line and tower.（4）A fuzzy risk assessment method for transmission line aging based on genetic algorithm optimization is proposed.Python is used to simulate the genetic fuzzy system,and charts are used to show the model training process and results of optimizing membership function parameters and fuzzy rules based on genetic algorithm.The simulation results show that the fuzzy risk assessment of transmission line aging optimized by genetic algorithm can describe the aging degree of transmission line more accurately...