摘要
10 kV中性点不接地系统发生单相接地故障时,如何快速、准确地选出故障相和故障线路,是亟待解决的问题。针对此问题,提出一种基于快速开关的故障转移选线方法。发生单相接地故障后,故障相上的快速开关检测到故障相后迅速合闸,将故障相稳定接地,从而将故障电流由故障点转移到快速开关上来。发生故障后,在快速开关合闸前后,故障相上非故障线路的零序电流均为零,故零序电流增量为零,而故障线路的零序电流在快速开关合闸前为非故障相所有线路零序电流之和,合闸后由于故障电流转移到了快速开关,使得其值变为零或者很小的一个值,故零序电流增量非常大。配合快速开关制造短路、转移故障电流,利用故障线路和故障相上非故障线路各自零序电流增量的显著差异,不仅可以比较快速、准确地选出故障相上的故障线路,切除以恢复供电,而且还可以有效解决故障点电弧重燃问题。仿真结果表明,提出的故障选线方法,可以有效提高选线的速度和准确率,对10 kV中性点不接地系统的安全稳定运行和电缆等设备的绝缘保护具有重要的实际意义。
When a single-phase grounding fault occurs in the 10 kV neutral ungrounded system,how to select quickly and accurately the fault phase and the faulty line is the urgent problem to solve.A fault line selection method based on fast switching is proposed in this paper to solve this problem.the proposed method can make a short circuit with fast switch to transfer fault current,and by using the significant difference between the zero-sequence current increment of the fault lines and the non-fault lines on the fault phase,not only can quickly and accurately select and cut out the fault lines on fault phase to restore power supply,but also can effectively solve the problem of arc re-striking at the fault point.The simulation results show that the proposed fault line selection method can effectively improve the speed and the accuracy of the line selection and is of great practical significance for the safety and stability of 10 kV neutral ungrounded system and the insulation protection of cables and other equipment of system.
作者
余振
黄刚平
李昌琼
殷神发
YU Zhen;HUANG Gangping;LI Changqiong;YIN Shenfa
出处
《青海电力》
2022年第4期1-9,共9页
Qinghai Electric Power
关键词
10
kV不接地系统
单相接地故障
快速开关
零序电流增量
故障选线
10 kV ungrounded system
single-phase grounded fault
fast switch
zero-sequence current increment
fault line selection
