Analysis And Visualization Research Of Transmission Line Thermal Aging Based On Meteorological Data

On the premise that China's increasing demand for power energy and the process of erecting new lines are restricted by many factors such as land and environment,improving the transmission capacity of existing transmission facilities and tapping the transmission potential of existing power grids have become one of the main development trends.However,the increase of transmission capacity will inevitably lead to the increase of current load of transmission lines,so the operating temperature of line conductors will also rise.Due to the material characteristics of the line,the aging process of conductor will also accelerate with the cumulative effect of a long time at higher operating temperature,which will accelerate the deterioration mechanism of components,and affect the sag length of the line and the failure probability of its operation.In this thesis we will study the thermal aging degree of transmission lines in a specific time interval on the premise of line capacity increase.Firstly,this thesis introduces the thermal ratting calculation model of CIGRE standard transmission line,as well as the related meteorological parameters and conductor characteristic parameters.On this basis,the paper introduced the calculation models of tension and strength loss caused by annealing of conductors of transmission lines with aluminium strands and steel-cored aluminium strands are introduced respectively,and then the application methods of the models in actual operation scenarios.Secondly,compared with the traditional static thermal rating(STR)technology,which uses the worst weather conditions to calculate the carrying capacity,and the dynamic thermal rating(DTR)technology,which has higher requirements for sensor deployment and information transmission technology,Quasi-dynamic Thermal Rating(QDR)with constant as the result of fixed value in defined time scale can comprehensively consider both implementation cost and transmission capacity increase.On the premise of QDR operation,the thermal aging of long-term transmission lines is studied based on the difference of maximum allowable carrying capacity between different confidence levels and different time scales.Based on the actual observation data of meteorological stations,the tension loss of transmission lines is evaluated,and the appropriate QDR operation scheme is determined according to the specified standards.Finally,the heterogeneity of thermal aging process of the same line in spatial span due to the differences of geographical,climatic and other environmental factors.The application of this method in space span is realized on the basis of defining the method of estimating the loss of line tension strength.Based on the actual space meteorological data,the line tension loss corresponding to the coordinate position of each pole and tower of the designated transmission line is estimated,and then we can identified key span and the key points of line thermal aging.According to the actual historical meteorological data observed by 2163 meteorological stations in China,we can get the potential thermal aging tension loss data,and the map of regional thermal aging of the line is drawn with the ArcGIS platform.In summary,on the premise of line capacity increase,the research on the thermal aging process caused by the rise of line operating temperature can effectively evaluate the thermal aging status of lines,estimate the potential thermal aging strength of designated areas and select the appropriate QDR operation scheme,which provides a basis for the maintenance and operation of power lines.