Characteristics And Risk Assessment Of Windage Yaw In UHV Transmission Lines

China's energy demand is enormous,and the distribution of resources is extremely uneven.With the increasing demand for electricity due to economic development,transregional transmission of power will be indispensable,and the construction of UHV lines is becoming more and more important.However,severe weather has occurred more frequently in recent years,and the smooth operation of transmission lines has been severely challenged.Because Windage yaw discharge is a major cause of transmission line failure,Windage yaw mechanism and Windage yaw risk assessment methods should be studied in depth.This paper studies the Windage yaw risk assessment of UHV lines,and mainly completes the following work:(1)The empirical calculation method of the wind angle of the transmission line is given,and the meaning and calculation method of the relevant calculation parameters are introduced in detail.According to the actual UHV transmission line,a refined transmission line-insulator string coupling model is established.The wind load is generated by numerical simulation method,and the influence of various influencing factors on the windage yaw angle is calculated.(2)According to the actual situation of the transmission line,a number of asymmetric finite element models are established to study the influence of different span and height differences on the windage yaw of the transmission line.According to the calculation results,the influence law of two-dimensional variation of height difference and gear distance on wind deviation is analyzed.By comparing the results of finite element calculation with those of empirical calculation method,the correction coefficient is fitted to improve the adaptability and accuracy of the empirical calculation method.Finally,the amplification effect of the pulsating wind on the windage yaw is studied,and the amplification correction coefficient under different wind speeds is obtained.(3)Firstly,the probability distribution model of meteorological elements is established.According to a large number of finite element calculation results,the KNN windage yaw angle prediction algorithm and the multivariate nonlinear regression windage yaw angle prediction model are established.The advantages of the two algorithms are combined to establish a combined wind yaw angle prediction model,and then the wind yaw angle is corrected by height difference and range change.Then,considering the characteristics of the air gap insulation performance,fitting the air gap breakdown voltage correction coefficient between the wire and the tower.Finally,an early warning model for windage yaw discharge of transmission lines is established.(4)The finite element model and windsge yaw early warning risk assessment model are programmed into an algorithm program,and then the visual operation calculation is realized through programming.