考虑线路压降的快速接地开关消弧性能及应用

快速接地开关兼具电压、电流双重消弧效果,但传统分析未考虑线路压降对故障点电流的影响,需进一步分析其消弧性能。考虑故障线路动态参数,建立应用快速接地开关的配电网单相接地故障模型,采用对称分量法推导出故障点电流计算公式。计算结果显示故障点电流受故障线路负载电流、序阻抗、相间电容、故障距离以及过渡电阻等多重因素影响。分析快速接地开关等效熄弧电路模型,表明快速接地开关可有效抑制间歇性弧光接地过电压,但在故障线路动态参数造成故障线路压降较大的稳定低阻燃弧过程中,快速接地开关可能增大故障点电流,不利于电弧熄灭。结合快速接地开关的优缺点分别对单独应用快速接地开关消弧及其与消弧线圈配合消弧提出建议。最后通过MATLAB仿真验证了文中的分析结果。

Arc Eliminating Performance and Application of Fast Grounding Switch Considering Line Voltage Drop

The fast grounding switch has both voltage and current double arc suppression effect, but traditional analysis does not take the effect of voltage drop on the current at fault point into account, which needs further analysis of arc suppression performance. Considering the dynamic parameters of the fault line, a single-phase grounding fault model of distribution network with fast grounding switch is established, and the expression of the fault point current is derived by the symmetrical component method. The calculation results show that the fault current is affected by multiple factors such as load current of fault line, sequence impedance, interphase capacitance, fault distance and transition resistance. The model of fast grounding switch arc circuit is analyzed to show that the fast grounding switch can effectively suppress intermittent arc grounding overvoltage. But in the process of stable low flame retardancy caused by the dynamic parameters of the fault line, the fast grounding switch may increase the fault point current, which is not conducive to the extinguishing of the arc. Combined with the advantages and disadvantages of the fast grounding switch, suggestions are put forward for its arc suppression application of fast grounding switch or cooperating with Petersen coil. Finally, the results of the analysis are verified by MATLAB simulation.