消弧线圈接地方式下的配电网单相接地故障模型分析  

Analysis of Single-Phase-to-Ground Fault Model in Network of Arc Suppression Coil Grounding

作　　者：刘家宁 LIU Jianing(State Grid Jilin Power Supply Company,Jilin, Jilin 132000,China)

机构地区：[1]国网吉林供电公司,吉林吉林132000

出　　处：《东北电力技术》2021年第12期40-46,共7页Northeast Electric Power Technology

摘　　要：我国中压配电网的短路故障类型80%为单相接地故障,由于非有效接地系统在发生单相接地故障后能够持续运行1~2 h,所以针对消弧线圈接地方式下的单相接地故障模型的分析十分必要,通过建立消弧线圈接地方式的配电网单相接地故障模型,从理论上分析在金属性接地、高阻接地以及中间状态下的不同过渡电阻等情况,利用ATP/EMTP仿真分析故障发生时的故障线路和正常线路以及消弧线圈上的电流波形的变化和差异,最终发现经消弧线圈接地方式下的配电网发生单相接地故障时,无论过渡电阻如何变化,故障线路和正常线路的零序电流突变方向是相反的,但零序电流的差异性随着过渡电阻的变化而变化,所以针对不同的故障接地电阻应利用不同的零序电路模型分析正常线路和故障线路的零序电流。80%of short-circuit faults in medium-voltage distribution network in China are single phase-to-ground faults.Since the non-effective grounding system can continue to operate for 1~2 hours after single-phase-to-ground faults,the analysis of the single-phase-to-ground fault model is necessary for the arc-suppression coil grounding mode.By establishing a single-phase ground fault model of the distribution network with arc-suppression coil grounding method,it is theoretically analyzed that the different transition resistances in metallic grounding,high-resistance grounding and intermediate state.Using ATP/EMTP simulation to analyze the fault occurrence,the change and difference of the current waveform on the fault line and the normal line are as well as the arc suppression coil.It is concluded that when the single-phase ground fault occurs in the distribution network under the grounding mode of the arc suppression coil,no matter how the transition resistance changes,the current direction of the fault line and the normal line is reversed when the predetermined reference direction is the bus flow lines.However,the difference between the fault current and the normal current is weakened with the change of the transition resistance.Therefore the different faults models should be used for different grounding resistances to analyze the transient currents of normal and fault lines on the zero sequence circuit model.

关 键 词：配电网 消弧线圈 单相接地故障 故障选线 故障电流 

分 类 号：TM727[电气工程—电力系统及自动化]