覆冰分裂导线扭转刚度研究

Study of torsional stiffness of iced bundle conductors

因分裂导线覆冰而导致的扭转刚度变化是舞动发生的重要原因之一,为了有效防治输电线路舞动,研究覆冰分裂导线扭转刚度很有必要.提出了一种考虑覆冰偏心的覆冰分裂导线扭转刚度计算方法,分析了覆冰对扭转刚度的影响.计算结果表明:覆冰导线的扭转刚度随覆冰量的增大而增大;常见易引发舞动的冰形中,扇形覆冰的偏心影响最大;覆冰偏心对扭转刚度有影响,初始结冰角越大,扭转刚度越大;覆冰导线在顺时针与逆时针的扭转刚度受覆冰偏心的影响基本相同,但临界扭转角和临界扭矩不同;不均匀覆冰会对分裂导线的扭转刚度产生显著影响.所得结果可为舞动的防治提供参考.

The torsional stiffness change caused by ice on the bundle conductor is one of the important reasons for galloping. In order to prevent and control transmission line galloping,it is very necessary to study the torsional stiffness of iced bundle conductor. A method is proposed to calculate the torsional stiffness of iced bundle conductors with consideration of the icing eccentricity, and the effect of icing on torsional stiffness is discussed. The calculation results show that the torsional stiffness of iced conductors increases with the increase of ice amount. Among the common icing shapes which can cause galloping, the eccentricity of sector ice coating has the greatest impact. The icingeccentricity affects the torsional stiffness, and the larger the initial ice angle is, the greater the torsional stiffness is. The influence of the icing eccentricity on the torsional stiffness of the iced conductor is basically the same under the clockwise and anti-clockwise torsion, but the critical torsional angle and the critical torque are different. Uneven icing has significant effect on the torsional stiffness of bundle conductor. The obtained results can provide a reference for preventing and controlling galloping.