特高压输电导线直流电场下过冷雨滴碰撞系数  

Collision Coefficient of Ultra-high-voltage Transmission Lines under Direct Current Electric Field

作　　者：周超[1,2] 孙剑峰 ZHOU Chao;SUN Jian-feng(Key Laboratory of Power Station Energy Transfer Conversion and System Ministry of Education,North China Electric Power University,Beijing 102206,China;Hebei Key Laboratory of Electric Machinery Health Maintenance&Failure Prevention,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学,电站能量传递转化与系统教育部重点实验室,北京102206 [2]华北电力大学,河北省电力机械装备健康维护与失效预防重点实验室,保定071003

出　　处：《科学技术与工程》2022年第35期15641-15649,共9页Science Technology and Engineering

基　　金：国家重点研发计划(2018YFC0809400);国家自然科学基金面上项目(52075169);北京市自然科学基金面上项目(8202043)。

摘　　要：在早春或初冬,过冷雨滴撞击导线表面结冰、进而易于诱发导线舞动。对碰撞系数或导线覆冰的研究主要集中在风速、雨滴大小和导线直径等关键参数上,鲜见涉及电场作用的讨论。为了阐明直流电场对输电线路碰撞系数的影响,提出了雨滴质量流量的计算公式,并用Euler-Lagrange方法对雨滴撞击导线表面的过程进行了数值计算。利用Fluent软件分析了电场强度、雨滴电荷密度、导线截面形状、风速等对碰撞系数的影响。结果表明,碰撞系数随电场强度的增加而减小。当电场强度从0增加到66.7 kV/cm时,碰撞系数降低约33%。由于带电导线与雨滴之间会产生排斥作用,部分雨滴远离导线,导致碰撞系数降低。真实绞线在无电场作用下的碰撞系数略小于简化圆形截面的碰撞系数。在直流电场作用下,当风速达到8 m/s时,导线的碰撞系数随风速的增大而减小。超过该阈值后,碰撞系数基本保持不变。In early spring or winter,supercooled raindrops impinging on transmission lines and then freeze on its surface,and by which galloping vibration occurs.Studies on collision coefficient or icing mostly focuses on key parameters of wind velocities,raindrop sizes and conductor diameters,whereas few involves electric field.In order to clarify the influence of the direct current electric field on the collision coefficient of transmission lines,a calculation formula of the mass flow rate of raindrops was proposed,and the process of raindrops hitting the conductor surface was numerically calculated by Euler-Lagrange method.The effects of electric field intensity,conductor diameter,cross-sectional shape,wind velocity,raindrop diameter and charge density on the collision coefficient of transmission lines were analyzed.The results show that the collision coefficient decreases with the increase of electric intensity.As the electric intensity increases from 0 to 66.7 kV/cm,the collision coefficient decreases about 33%.Because of the repulsion between the conductor and raindrops,more raindrops move away from the conductor surface and collision coefficient decreases.The collision coefficient of the actual conductor under no electric field is slightly smaller than that of the simplified circular cross-section.Under DC electric field,the collision coefficient of the conductor decreases with wind velocity increase up to 8 m/s.Beyond that threshold,the collision coefficient almost constant.

关 键 词：输电线路 碰撞系数 直流电场 数值模拟 

分 类 号：TM726[电气工程—电力系统及自动化]