重合时序对交直流混联输电系统暂态稳定裕度的影响

单相重合闸技术可以提高供电可靠性，但合于永久故障时是对系统的又一次冲击，因此研究重合的时序对系统暂态稳定裕度的影响是十分必要的。文中以南方电网2005年丰大运行方式下安顺—天生桥500 kV线路发生单相接地短路为例，在未有效区分永久故障和瞬时故障的前提下，以FASTEST为仿真工具，考查了重合闸时序对系统暂态稳定裕度的影响。仿真研究表明，改变线路两侧轮流投入无压检定的做法，由线路非故障侧投入无压检定首先重合，不仅可以较大幅度地提高系统暂态功角、电压和频率稳定裕度，也可以改善2次切断短路电流的断路器的工作条件。并提出了一种与故障测距算法相结合的在线修正线路两侧投入重合闸顺序的方案，以期减少重合于永久故障时对系统的再次冲击，提高系统的暂态稳定性。

Influence of Single-phase Reclosing Sequence upon Transient Stability Margin of AC/DC Hybrid Transmission System

Single-phase reclosing technique can enhance the service reliability, but when reclosing to permanent faults, it brings about another surges to power systems. Hence it is necessary to study the influence of reclosing sequence on transient stability margin. In this paper, Taking an single phase ground fault on Anshun-Tianshengtiao 500 kV transmission line of Southern China Power Grid with 2005 year's flood season-large power flow as an example, the influence of single-phase reclosing time sequence on transient stability margin is simulated by FASTEST software without effectively distinguishing the transient and permanent fault. The simulation results indicate that reclosing firstly by using non-voltage detecting at non-fault terminal instead of at two terminals in turn can enhance the transient angle, voltage and frequency stability margin greatly, and improve the working condition of breaker to cut off short-circuit current twice. Based on this, an online reclosing method combined with fault location algorithm to modify single-phase reclosing sequence is proposed to enhance transient stability and decrease the surge when reclosing to permanent fault.