Dynamic wind-induced swing response and parameters’ influence #br# analysis of UHV transmission lines
Lou Wenjuan1 Bai Hang1 Yang Xiaohui2 Luo Gang1,3
1. Zhejiang University, Hangzhou 310058, China;
2. State Grid Henan Electric Power Company Electric Power Research Institute, Zhengzhou 450052, China;
3. China Energy Engineering Group Zhejiang Electric Power Design Institute Co., Ltd., Hangzhou 310012, China
Abstract：Wind-induced swing of UHV (ultra high voltage) transmission lines is easily influenced by structure parameters, thus it is conducive to study the relationship between so as to prevent the flashover accidents. The aerodynamic parameters of eight-bundled conductors and insulator strings were measured by the wind tunnel test. Frequency-domain method for wind-induced swing analysis of multi-span continuous UHV transmission lines was performed in two steps. Firstly, the mean response was studied by the non-linear static analysis. And then the fluctuating response was investigated by the linear analysis in frequency domain, taking the configuration and stiffness in static state as initial condition and introducing the aerodynamic damping which considered the influence of in-plane modes. Two-step frequency-domain method is more efficient than time domain method with high accuracy. Aiming at the UHV 1000kV Nan-Jing line I, a four-span wire-insulator FEM was established. Taking intensive natural frequencies and complex models of multi-span conductors into consideration, the number of participant models was determined by the energy method. Using frequency-domain method in two steps, the mean and fluctuating wind-induced swing responses were figured out with different structure parameters and the rigid rod method recommended by the standard was proved to be lack of accuracy. Research results show that if there is height difference in the transmission line, towers with low nominal height are more likely to suffer flashover accidents. The wind-induced swing of towers with low nominal height increases as nominal height of adjacent towers and the working tension, while it decreases with the span. Compared with the change of span, the wind-induced swing is more sensitive to the change of altitude difference.
