连续档导线面内及面外等效刚度研究

The research for in-plane and out-plane equivalent stiffness of continuous span transmission lines

针对边界条件对架空输电线路舞动的重要影响,建立了简化相邻档导线及绝缘子串为等效弹簧的计算方法。首先根据悬垂索的抛物线理论推导单档导线和两档导线的面内等效刚度计算公式,然后将其推广到任意档导线的面内等效刚度计算;依据小弧垂及水平张力不变假设推导了两档和三档导线面外等效刚度的计算方法。将具体算例与有限元计算结果进行比较,最小误差仅为0.4%,表明等效刚度的计算方法具有较高的精度。同时,算例分析表明:单档导线、两档导线、三档导线的面内等效刚度差异均较大,最大误差可达35%;两档导线和三档导线的面外等效刚度差别较小,最大误差仅为0.68%。等效刚度计算方法为覆冰导线舞动研究所需边界条件计算提供了方便有效的工具。

The calculation method of simplifying adjacent span line and insulator string as equivalent spring is established,which is based on the important influence of boundary condition on the overhead transmission line galloping. Firstly, the calculation formula for in-plane equivalent stiffness of single-span and two-span transmission line is obtained,according to the parabola theory of suspended cable. Then,the formula can be extended to the calculation of in-plane equivalent stiffness for any continuous span transmission line. The calculation method for out-plane equivalent stiffness of two-span and three-span transmission line is obtained,according to small sag and the assumption that the horizontal tension is constant. Comparing the specific example with the calculation results of finite element,the minimum error is 0.4%,it indicates that the calculation method of equivalent stiffness has higher precision. Moreover,the analysis of example also indicates that the difference for in-plane equivalent stiffness of single-span,two-span and three-span transmission line is large,the maximum error is 35%; but the difference for out-plane equivalent stiffness of two-span and three-span transmission line is small, the maximum error is 0.68%. The calculation method of equivalent stiffness provides a convenient and effective tool for the study of iced transmission line galloping.