750kV输电导线不均匀覆冰弧垂变化与脱冰跳跃研究

Research on uneven iced transmission lines and the dynamic response after ice-shedding

采用有限元方法分析了750 kV超高压输电线路不均匀覆冰状态下导线的弧垂变化规律和脱冰跳跃响应规律。建立了“绝缘子串-六分裂导线”模型,对比分析了均匀覆冰、三段覆冰、线性覆冰和高处覆冰等工况下导线弧垂变化形态及其脱冰动力响应,分析了高处覆冰工况下档数、档距、高差、覆冰厚度、脱冰率等因素对导线的形态变化及其脱冰跳跃高度的影响。结果表明,导线的变形和脱冰跳跃高度随着档数、档距、覆冰厚度的增大而增大;中间档高差增大时,导线沿水平方向的偏移增大,而脱冰跳跃高度表现出减小的趋势;在均匀覆冰下中间档档距为1000 m时,导线脱冰跳跃高度出现峰值,为25.627 m。

The finite element method is used to analyze the deformation law and ice-shedding dynamic response law of 750 kV EHV transmission line under uneven icing condition.The model of“insulator string six bundle conductor”is established,and the conductor shape and its ice-shedding dynamic response under uniform icing,three section icing,linear icing and high altitude icing are compared and analyzed.The influences of span number,span length,height difference,icing thickness and ice-shedding rate on the shape change and ice-shedding jump height of conductors under high altitude icing conditions are mainly discussed.The results show that the conductor deformation and ice-shedding jump height increase with the increase of span number,span length and icing thickness.When the height difference of the fourth span increases,the slip along the horizontal direction of the conductor increases,while the ice-shedding jump height decreases.When the fourth span is 1000 m under uniform icing,the ice shedding jump height of the conductor has a peak value,which is 25.627 m.The above research results show that the UHV transmission line is uniformly covered.