Numerical Analysis Of Headline-Icing And Its Effect On Corona And Galloping

There are multiple secondary order effects caused by icing except of mechanical faults on the headline such as corona strengthen due to the change of electromagnetic environment around iced-headline and abnormal of line galloping under certain wind speed, which can lead to dangerous to some extent for line save operation. This thesis numerically analyzed the change of electromagnetic and simulated the galloping qualitatively for iced-line.Based on the characteristics of airfoil mixed-phase ice caused by the wind which is vertical to conductor, a two-dimensional simulating model is established by FLUENT/GAMBIT and By Finite Volume Method(FVM), icing weight and properties at different velocity and humidity are compared respectively.Because the electric field on conductor surface is distorted by icing, corona discharge is aggravated. Using MATLAB/PDE the electric field of 110kv AC, unipolar 100kv DC, bipolar±500kVDC and 500kV four-bundle iced-line are simulated, respectively. The power frequency electromagnetic field is considered into quasi-static field in the case of calculating AC electric field above. Meanwhile the corona discharge of different type transmission lines caused by electric field distortion of iced-line are compared. The electric potential and electric field between bipolar±500kVDC effected space charges is also simulated, In addition, the other reasons resulted in corona discharge are discussed.According to newton's second law and d'Alembert principle, we have considered the galloping model of headline as a transverse vibrations of string fixed on two ends and built mathematical model of galloping line shown by the transverse vibrations equation of a single-freedom vibration string. Meanwhile,based on MATLAB we simulated headline galloping affected by wind, wind-damp, anduneven distribution of iced load.The results of dynamic simulation show the galloping in different conditions obviously. The caculating results have a certain reference value for further study of relevant projects.