物联网下谐波电流差动保护在小电流接地系统中的选线及定位研究

Line Selection and Location of Distribution Network Harmonic Current Differential Protection in Small Current Grounding System under Internet of Things

为了提高供电可靠性,快速找到在经消弧线圈接地情况下单相接地故障的故障点位置,防止瞬时故障发展成永久故障,研究了在物联网下,电力5G通信方式基础上,通过判定3次及5次谐波电流实现快速差动保护的可行性。通过仿真,对配电系统中架空线路、电缆线路,以及在线路首端或者末端,过渡电阻影响下差动保护等进行了分析,可以有效避免故障范围扩大,以满足供电可靠性要求并提升配电网继电保护水平。

In order to improve the reliability of power supply,locate as soon as possible the fault point of the single-phase grounding fault in the case of the arc suppression coil grounding,and prevent the transient fault from developing into a permanent fault,this paper studies the feasibility of fast differential protection determined by the 3 rd and 5 th harmonic currents under the Internet of Things and on the basis of 5 G network communication method.The overhead lines and cable lines in the system are analyzed by simulation and the differential protection can be effectively reduced under the influence of the transition resistance.The scope of minor faults is expanded to meet the reliability requirements of power supply and improve the relay protection level of the distribution network.