500 kV覆冰四分裂导线舞动特性

输电导线舞动是线路运行中常见的现象,舞动会导致输电线路发生电气和机械事故。为了保证电网的安全稳定运行,有必要深入研究线路舞动的特点。为此,建立了3自由度多档导线的运动模型,利用Fluent计算空气动力学参数,针对一条500 kV覆冰四分裂导线的舞动影响因素进行了详细研究。采用基于中心差分的显性直接积分算法,通过数值计算,比较了不同风速、覆冰厚度、导线型号下的舞动情况,并分析了导线突然脱冰时的舞动情况。研究结果表明:在起舞风速与舞动最大幅值对应的风速之间,舞动幅值随风速的增加近似呈现线性增加的趋势;厚覆冰更易发生舞动,但厚度过大会破坏舞动;在相同的覆冰条件下,小截面导线比大截面导线更易产生舞动;导线突然脱冰后,舞动幅值迅速下降,仅做小幅度摆动。研究结果对实际工程中500 kV导线在不同气象条件下的舞动幅值预测及防舞技术的应用具有一定的指导作用。

Galloping Characteristics of 500 kV Iced Quad Bundle Conductor

Conductor galloping is common during the operation of transmission lines, which may result in electrical and mechanical accidents of the transmission line. In order to ensure the safety and stable operation of power grid, it is necessary to study the characteristics of galloping deeply. The multi-span 3-degree-of-freedom(3 DOF) dynamic model for conductor was established in this paper, and the aerodynamic parameters were calculated by the Fluent software, and the research on a 500 kV iced quad bundle conductor galloping was also conducted in detail. Based on the explicit central difference integral algorithm, the galloping conditions under different wind speeds, ice thickness, wire types were discussed, and the results under sudden ice shedding were analyzed. The research results show that the amplitude between the minimum and maximum wind velocity that leads to gallop will increase almost linearly corresponding to the wind velocity;the increasing ice thickness makes the conductor easier to gallop, but too large thickness will destroy the conductor galloping;under the same ice cover, the small cross-section conductor is easier to produce galloping;sudden ice shedding will rapidly decrease the galloping amplitude, leading to a small vibration. The research results have a certain guiding effect on the prediction of the amplitude of the 500 kV wire in actual engineering under different meteorological conditions and the application of anti-dance technology.