减小电压暂降深度及持续时间的单相重合闸时序方案

为了减轻单相重合闸重合失败时敏感负荷的电压暂降深度及持续时间,提出一种单相重合闸时序方案。当线路发生单相接地故障且两侧保护动作跳开故障相断路器,利用故障分量概念构建故障附加状态网络,在线路两端分别接入附加电源,计算敏感负荷节点的故障分量电压。依据敏感负荷节点故障分量电压幅值大小确定重合闸时序,幅值小的一侧先重合。线路先重合侧重合后,后重合侧利用线路电压幅值大小判别是否开放重合闸。PSCAD/EMTDC仿真结果表明该方法不受过渡电阻和故障位置的影响,能够改善敏感负荷的电压电能质量。

Single-phase Reclosing Sequence for Reducing Voltage Sag Depth and Duration

In order to reduce the voltage sag depth and duration of sensitive load when the single-phase circuit breaker reclosing fails, a scheme of single-phase reclosing sequence is proposed. When a single-phase grounding fault occurs on the line, the protections on both sides act and fault phase breakers are tripped. The concept of fault component is used to construct the fault additional state network. Additional source is added to each end of the line to calculate the fault component voltage of the sensitive load node. The reclosing sequence is determined according to the magnitude of fault component voltage of sensitive load node. The side with smaller magnitude is determined to reclose first. After one side of the line is reclosed, the magnitude of line voltage is used to judge whether the reclosing is open or not at the other side. PSCAD/EMTDC simulation results show that this method is not affected by transition resistance and fault location and can improve the voltage power quality of sensitive load.