四分裂导线运行电流分组融冰方法与现场试验

De-Icing Method and Field Test of Four-Bundled Conductor by Loading Operating Current on Grouped Sub-Conductors

输电线路导线覆冰事故严重威胁电力系统的安全、可靠运行,特别是500 kV网架主干线路一旦发生覆冰事故,可能导致系统解裂。提出了利用四分裂导线运行电流分组融冰方法,并进行了现场试验验证。研究结果表明:四分裂导线采用绝缘间隔棒,并在需要融冰的线路档距两侧安装合适的分合闸控制开关,可将分裂导线运行电流集中到某一根子导线或某一组子导线上,从而提高该融冰子导线电流密度并实现融冰;四分裂导线的覆冰形状和类型与气象环境参数有关;四分裂导线融冰过程包含导线升温冰层旋转阶段、冰层融化阶段和冰层脱落3个阶段;采用合理的四分裂导线运行电流分组融冰方法,可以实现四分裂导线融冰和脱冰,其融冰快慢与电流、环境温度、风速等有关。

The faults caused by ice coating on transmission lines seriously endanger secure and reliable operation of power system,especially,once the ice coating-caused fault occurred in main transmission lines of 500 kV backbone power network,it may leads to the splitting of entire power system.A grouped de-icing method for four-bundled conductor,which divides the four sub-conductors of bundled conduction into groups and the operating current was switched to one of the group to melt the ice coating,was proposed and corresponding field test was performed to verify the proposed method.Test results showed that using the insulating bundled conductor spacers and installing suitable switches and controllers at both ends of the spans where the ice coating should be removed,the operating current of the transmission line could be centralized to a certain sub-conductor or a certain group of sub-conductors,thus the current density of sub-conductor or the group of sub-conductors was increased and the de-icing could be implemented;the shape and types of ice coating on four-bundled conductor related to meteorological and environmental parameters;the de-icing process of four-bundled conductor included three stages,i.e.,the temperature rising and rotating of ice layer,the melting of ice layer and the falling of ice layer;adopting the proposed de-icing method by loading operating current on grouped sub-conductors,the ice melting and ice layer falling for four-bundled conductor could be implemented,and the de-icing speed depended on the magnitude of operating current,environmental temperature and wind speed.