【摘要】 中低压6～66 kV配电系统中,架空线路单相断线接地复故障时有发生,危及人身安全,影响电力负荷正常运行。在考虑接地点在负荷侧及考虑负荷性质的前提下,对小电流接地系统单相断线接地复故障时保护安装处、断线点、接地点和负荷侧的电流、电压进行分析,并导出各点电压、电流的计算公式,绘出相应的电压、电流相量图。分析表明,保护安装处、接地点及负荷侧的电压与负荷性质和过渡电阻有关;断线相断线点的电压与负荷性质有关。用PSCAD仿真验证上述结论的正确性。研究结果为小电流单相接地故障、单相断线故障和断线接地复故障的判断提供了理论依据。更多还原

【Abstract】 Single-phase grounding faults with line-broken occur frequently in overhead distribution systems of 6~66 kV,which may endanger personal safety and interrupt power supply.Considering the grounding points on load side and the types of loads,the currents and voltages at grounding and broken points and protection installation positions and on the load sides were analyzed respectively,and the formulas and phasor diagrams of voltages and currents at each point were deduced.The study results show that voltages of grounding points and protection installation positions have a relationship with load characteristics and fault resistance.However,the broken point voltage has a relationship with load characteristics only.PSCAD simulation proves correctness of the conclusions.Thus a theoretical foundation is established to identify the single-phase grounding faults,line-broken faults and grounding faults with line-broken.更多还原