Research On Torsional Characteristics And Overturning Prevention Of Split Conductors Of Transmission Lines

Transmission line failure under ice wind load is an important component of transmission line operation failure,which mainly includes wire twisting and flipping.There are many factors affecting the twisting and flipping of the split conductors of transmission lines,and they do great harm to the normal operation of transmission lines.In this paper,the mechanical characteristics of single stranded wire are analyzed,the torsion and reversal characteristics of split wire are analyzed,and the torsion dancing prevention and control analysis is carried out,which provides reference for the design,check and normal operation of transmission lines.The main research contents and results are as follows:The mechanical model of stranded wire is established,the relationship of loose twisted torque,stress and strain is analyzed,the calculation formula of axial force and torque of stranded wire is improved considering the Poisson effect of material and contact stress,and then the calculation formula of equivalent torsional stiffness of stranded wire is obtained,which lays a foundation for line analysis.The theoretical analysis and calculation of torsional stiffness of split conductor are carried out for transmission lines,and the simplified calculation formula is given.The correctness of the calculation method and finite element simulation analysis method of torsional stiffness of split conductor is verified by the comparison of the results of double-scale test and finite element simulation.In tension and span on solid conductor torsional rigidity influence,on the basis of simulation analysis was carried out by dividing the number,wire torsional rigidity,span,and the initial tension of split line simulation analysis of the influence of torsional rigidity,and found that the more the conductor division number,initial tension and lead the torsional rigidity,the greater the torsional rigidity of line,the greater the line distance and secondary distance,the smaller the torsional stiffness.Transmission lines under the action of the concentrated load torque split conductor flip characteristic has carried on the dynamic simulation analysis,to study the ice wind under combined load circuit flip feature,establishes a circuit flip overturning failure ice wind conditions,mechanical calculation model is established for flip lines since the restoration,advanced the theory of circuit flip the restoring moment calculation formula,The results of scale test and finite element simulation show that the method has certain accuracy.The influence of line parameters on rollover self-recovery characteristics is studied by theoretical calculation formula and finite element method.The anti-dance simulation analysis of the existing double pendulum anti-dance device is carried out,and the arrangement mode and the best scheme of the pendulum quality of the double pendulum anti-dance device are established.The anti-flipping scheme of cable is designed,and the anti-flipping mechanism and anti-flipping effect are analyzed.It is found that the anti-flipping effect is better with the increase of cable stiffness,but there is an upper limit.Compared with the double-swing anti-flipping scheme,the anti-flipping effect of cable is better.