一种适用于谐振接地系统的动态电阻选线方式

Line Selection Method Based on Dynamic Resistance for Resonant Grounding System

为突破谐振接地系统选线瓶颈,提出一种动态电阻选线方式,运用理论分析和ATP-EMTP仿真试验,确定了选线程序启动方式与动态电阻阻值选取办法。其次通过分析电路模型,得到动态切换为电阻接地方式后的阻性注入电流表达式。最后在国网配电智能化应用及关键设备联合实验室进行现场试验,验证了在谐振接地系统发生永久性单相接地故障时,动态电阻选线方式能准确识别故障发生,判断故障性质,通过阻性电流注入准确选出故障线路,过渡电阻识别能力达到3 500Ω,为谐振接地系统单相接地选线难题提供了一种有效可行的实际解决办法。

In order to solve the problem of difficulty in line selection of the resonant grounding system,the author proposes a dynamic resistance line selection method. Using the oretical analysis and ATP-EMTP simulation test,the procedure of the method and the selection method of resistance values are determined. By analyzing the circuit model,the expression of the resistive injection current after dynamic switching to the resistance grounding mode is obtained. The field test was carried out in the joint application laboratory of the State Grid,which verified that this method can accurately identify the fault when the permanent single-phase ground fault occurs in the resonant grounding system,and judging the fault nature. By injecting the resistive current,the fault line is accurately selected,and the transition resistance recognition capability reaches 3 500 Ω. It provides an effective and practical solution for the single-phase grounding line selection problem of the resonant grounding system.