Research On Simplified Analysis Method Of Random Wind-Vibration Response Of Transmission Tower-Line System

With the rapid development of the national economy,the transmission line is an important project for people’s livelihood,and its structural safety is related to the safety of people’s lives and property and the stable operation of the economy and society.With the rapid rise of domestic power consumption,the transmission line system has gradually developed into a large-scale structural system with complex and changeable forms,which puts forward higher requirements for wind-resistant design and theoretical research of transmission tower line systems.The strong nonlinearity of the transmission line makes the tower-line system also exhibit highly flexible nonlinear characteristics,and it is extremely sensitive to wind loads.Therefore,it is of high economic value and significance to analyze the wind-induced vibration response.In the current theoretical analysis method of transmission tower and line system,the time-domain analysis method is usually used to analyze the wind and vibration response of the tower and line system,but this method consumes relatively more computing resources and it is difficult to quickly achieve the wind resistance of the target tower body in the system.design.In view of this,this paper establishes a simplified analysis mechanical model of the wind-induced response of the tower-line system through the spectral analysis method based on the load power spectrum of the line hanging point,and converts the nonlinear tower-line system into an approximately linear transmission tower structure A simplified analysis method for random wind-induced vibration response of tower-line system based on the load point load power spectrum is proposed.Secondly,this paper considers that the tower line system will be affected by many factors in the field environment,and the load of the hanging point will also change with the change.Therefore,this paper has carried out the power spectrum of the hanging point load for different wind speeds,gear distances,transmission tower height and other factors.The analysis of the influence of parameters,the introduction of appropriate change coefficients to correct the power spectrum empirical formula,and the comparison with the actual power spectrum curve,the results show that the empirical formula is corrected to fit the actual situation well.Then,based on the load power spectrum of hanging point,the paper researched the calculation method of gear reduction factor.Due to the wide spatial distribution of transmission lines,the wind speed acting on the conductors at the same time cannot be completely the same.Therefore,the power industry introduced a gear reduction factor to characterize this situation and reduce the wind load on the conductors accordingly.However,there is still little research in this field,and the considerations are not comprehensive.In this paper,when the actual load power spectrum of the transmission line is obtained,based on the equivalent static wind load calculation theory,a new gear reduction factor that can consider the influence of wind speed,gear distance,hanging point height and other factors is derived The calculation method,the value of the calculated coefficient is basically consistent with the recommended value of the code,which shows the feasibility of the method proposed in this paper,and also indirectly verifies the correctness of the empirical formula of the load point power spectrum.Finally,based on the power spectrum of the hanging point load,a simplified mechanical model for the wind-induced response of the tower-line system is established,and the correlation between the hanging point load of the conductor and the wind load of the transmission tower is analyzed,and the mechanical model is obtained reasonably.Hypothesis.On this basis,combined with the virtual excitation method and hanging point load power spectrum empirical formula,a simplified analysis method for the random wind-induced vibration response of the transmission tower-line system is proposed,and compared with the tower top displacement response obtained by the time history analysis method To verify the feasibility of this method.