| With the continuous increase of power demand in China,the number of transmission lines have been increasing.At present,a number of UHV transmission lines,which are mainly constructed by tension stringing method,have appeared in China.There are some faults which occurs during the construction of tension stringing,and some of which are mainly due to flexibility of cable in the system.Although there are some precautions and treatments for these faults,it is necessary to stop the machine,check and repair when a fault occurs.In addition,the construction of tension stringing is carried out intermittently:The required time for the construction of transmission lines is increased due to these phenomenons.Based on the engineering background of a construction process in the certain section of Ximeng-Shandong l000kV UHV transmission line,the vibration under the quasi-static conditions of the system and the dynamic characteristics during stringing process is studied in this paper.The main research contents of the thesis include:(1)Based on the tension stringing construction specification of UHV transmission line,the key component size parameters,drawing force and tension in the section are calculated,and the actual process is simplified into a cable-pulley system.In addition,the theory of vibration analysis and the method of solving the dynamic equations of the rigid-flexible coupling system is also introduced in the paper.(2)The rigid parts such as pulleys and drawing plates in the simplified system are simplified to the constraints and forces on the cable.Then finite element vibration analysis is studied,which mainly includes modal analysis,harmonic response analysis,and spectral analysis under sinusoidal excitation and random excitation.(3)Based on the spatial description method,the movement of the cable-pulley system is established.And combined with the relationship between space description and material description and the virtual power principle,each part of the rigid-flexible coupling dynamic equations in the system is established.Finally,the dynamic equations of the system is obtained by combining partial equations.(4)Dynamic equations of system is separated to solve since each part of it is independent.Based on the noise-reduction model method,the motion of ideal system caused by the external force difference between the two ends of the pulley when stringing speed is zero is analyzed.The equivalent simulation using ADAMS software is performed for comparsion,and the applicable conditions of modeling method are obtained.Finally,the dynamic characteristics of the key components of the actual system when stringing speed is zero,constant and variable are studied.Through the research,some ideas and suggestions such as system vibration reduction and selection of law of tension stringing are put forward in this paper,which can improve the construction efficiency of tension stringing while the construction quality is ensured and increase the degree of automation of the construction process in a certain extent. |
