±1100 kV特高压输电塔线体系风振响应分析

Wind Induced Vibration Response Analysis of±1100 kV Ultra-high Voltage(UHV)Transmission Tower Line System

为研究角度风下长横担输电塔线体系动力响应,采用有限元时程方法分析准东—华东±1100 kV特高压输电线路单塔及塔线体系风振响应。首先,利用线性滤波法计算得到三维脉动风速场,并结合准定常理论得到单塔及输电塔线体系脉动风荷载。其次,建立单塔及输电塔线体系有限元模型,利用模态分析方法计算结构的动力特性,研究导地线及长横担结构对输电塔动力特性的影响。最后,利用有限元时程方法对单塔及塔线体系进行动力分析,研究了风向角、长横担结构及塔线耦合效应等因素对结构动力响应的影响。结果表明:长横担结构会导致扭转频率降低,扭转振型出现顺序前移;塔线耦合效应降低了塔架结构自振频率,提高了结构阻尼比;根据位移均值计算结果,最不利风向角为15°和75°;根据扭转角均方根计算结果,最不利风向角为0°;单塔顺风向响应主要受背景分量和1阶振型的影响,塔线体系还受到导地线低阶共振分量的影响,扭转角主要受扭转1阶振型影响。

To investigate the dynamic response of long cross-arm transmission tower-line system under skewed wind,finite element time history analysis on wind-induced response of a single tower and the tower line system of Zhundong-Huadong±1100 kV UHV transmission lines was conducted.Firstly,three dimensional fluctuating wind velocity was obtained using the linear filter method,and then fluctuating wind load of a single tower and the tower-line system was calculated combined with quasi steady theory.Secondly,the finite element models of a single tower and tower-line systems were constructed.Dynamic characteristic of tower line system was obtained using modal analysis,and the effects of the grounding wire and the long cross-arm structure on dynamic characteristic were studied.Finally,this paper used the finite element time history analysis approach and studyed the effects of incident angles,the long cross-arm structure and tower line coupling on structural dynamic responses.The results proves that the long cross-arm structure results in the decrease of torsional frequency and moves the occurrence order of torsional model forward.Besides,tower-line coupling reduces the frequency and increase the damping ratio of tower structures.According to the mean displacement calculation results,the most unfavorable wind incident angles are 15°and 75°,respectively;According to the root mean square of torsion angles,the most unfavorable wind direction angle is 0°.In addition,the along wind response of the tower is mainly affected by the background component and the first order vibration mode,while the tower line system is influenced by the low order resonance component of the ground wire additionally,and the torsion angle is mainly influenced by the first order torsional vibration mode.