The Research Of Aeolian Vibration And Wake Induced Subspan Oscillation Control For Transmission Line

Aeolian vibration and subspan oscillation very easily lead to damage of overhead transmission lines and electric power fittings, which has a very serious threat to the safe and reliable operation of transmission lines. With the Ultra-high Voltage(UHV) transmission lines of large-scale constructed in China, as the transmission lines in diameter, weight per unit length has increased, the suspension height also increased, therefore, their vibration condition becomes more serious. Moreover UHV transmission project as a great influence lifeline project, if be destructed would lead to huge economic losses and other secondary disasters. In order to ensure the safe operation of UHV transmission lines, a higher demand was put forward to the vibration control of aeolian vibration and subspan oscillation, but theoretical calculation of the current difficult to meet the needs of engineering design. There was an urgent need in this regard to conduct in-depth research.In this dissertation, the studies on the control of aeolian vibration and subspan oscillation of power transmission lines are performed. The research content includes: improvement of energy balance method, vibration solution of stockbridge dampers-conductor coupling system, calculation theory of energy damping of wire damper, the indoor simulation experiments of aeolian vibration, precise calculation theory of aeolian vibration of bundle conductors, the largest subspan distance of bundle conductors and optimize the layout of spacer dampers. The specific contents are as follows:Firstly, the causes of energy balance method result has some errors is analyzed. Then energy balance method is improved from the following aspects: the wind power input, the conductor self-damping, the damper dissipated power and vibration solution of Stockbridge dampers-conductor coupling system. So that improved energy balance method can consider more influential factors to enhance accuracy. Then computer-aided calculation procedures were programed based on the improved energy balance method, which lay the foundation for the control of aeolian vibration research. After the theoretical mechanical model of wire damper is built, the large static deformation of wire damper is solved and established by using singular perturbation method, so the influence of wire damper's design parameters on the static line shape, internal forces are studied. The vibration control equation of wire damper is solved by Galerkin method, so the vibration frequency and internal forces response are obtained. Then energy dissipation calculation formulae of wire damper are derived, so the vibration energy dissipated by wire dampers can be considered in energy balance method. Theoretical calculation results were compared with the results of laboratory tests, the results proved the correctness of theoretical calculations.In order to verify the results of theoretical studies, the indoor aeolian vibration simulation tests are designed. Through the conductor self damping measurements verified the rationality of improved formula for calculating transmission line self damping; through the damping tests of stockbridge damper is installed in different location, indirectly verified the correctness of the location optimized calculation of the stockbridge damper; through the damping test of wire dampers, the correctness of damping energy calculated theory of wire dampers are proved.A mathematical model of damping spacer damper is established, then the impedance matrix and energy consuming formulae of spacer dampers are derived. Afterward, vibration equations of bundle conductors system which consider the effects of spacer dampers are derived(including transcendental function and plural), the vibration frequencies and modes of bundle conductors system are got by solving the transcendental eigenvalues of these equations. Then the amplitude ratio of each spacer dampers to sub-conductors are got, so bundle conductors can be exactly solved with the application of energy balance method as single-conductor.The influencing factors of bundle conductors' subspan oscillation are introduced, then largest subspan distance of bundle conductors are calculated with considering anti-adsorption conditions, the amplitude limitations of sub-conductors and requirements of the reverse recovery characteristics. Afterwards, the calculation method of optimal spacer placement in the bundle conductor span is given out. At last, two new tentative control schemes for subspan oscillations are presented.Study the aeolian vibration control of transmission lines and subspan oscillation control of bundle conductors has great theoretical significance and social economic significance. The work of this dissertation hopes to provide some useful reference for the construction of UHV transmission projects, hopes to provide a more effective theoretical basis for the design of aeolian vibration control and subspan oscillation control, and hopes to lay the foundation for a more in depth study of this subject in the future.