同塔双回线路同名相跨线短路故障分析

Analysis of homogeneous phase cross-country faults of double-circuit lines on the same tower

分析了高压电网同塔双回线路发生同名相跨线不接地短路的电气特征,通过仿真验证了纵联电流差动保护的动作行为。进一步论证了同名相跨线不接地短路向接地故障以及相间故障转化的可能。结合现场工程案例,分析了220 kV同塔双回线路在运行方式发生改变时,同名相跨线不接地短路的存在给变电运维人员倒闸操作带来的问题与风险。最后提出了制定巡线计划、推进智能运检等相应的防范措施,强调了提升输电线路巡视质量对于电网隐患及时消除的必要性。

The electrical characteristics of a homogeneous phase and non-grounding short-circuit of double-circuit lines on the same tower in a high voltage power grid are analyzed,and the behavior of the current differential protection is verified through simulation.The possibility that the homogeneous phase and non-grounding short-circuit across the lines are converted to ground faults and phase-to-phase faults is highlighted.Based on the field case,this paper analyzes the risks caused by the homogeneous phase and non-grounding faults to the normal operation of the power grid and the switching operation of maintenance personnel when the operation mode of the 220 kV power system changes.Corresponding preventive measures such as the establishment of a line inspection plan and the promotion of intelligent operation inspection are put forward,and the necessity of improving the quality of transmission line patrols to eliminate,in time,hidden dangers is emphasized.