基于线路相位差同趋性的电力系统自适应失步解列断面实时搜索方法

Real-time Searching Method of Adaptive Out-of-step Splitting Surfaces for Power System Based on the Line Phase Difference With the Same Trend Variatio

解列控制作为电网运行的第三道防线,对于防止系统崩溃具有重要意义。传统失步解列装置依赖振荡中心判别,无法适应多变的运行方式和复杂的失稳模式。基于双机等值系统,该文通过理论推导得出,振荡中心所在线路两端相位差随着两侧机群功角摆开而增大,并最终超过90°;而其他线路两端的相位差则在增大到一定程度后迅速减小,不会超过90°。利用线路相位差同趋性变化特征可以有效搜索系统振荡中心所在断面,且不受系统运行方式和故障形态的影响,无需仿真分析。通过新英格兰10机39节点算例和实际电网算例验证该文方法的准确性。结果表明,该方法能够准确抓住电网振荡中心,计算量小、速度快、适应性强,具有很好的工程实用价值。

As the third defense line of the power grid, the splitting control system is of great significance to prevent the system from collapsing. The traditional out of step splitting device depends on the judgment of the oscillation center, which is unable to adapt to the changing operation mode and the complex instability mode. Based on the double machines system, the conclusion acquired through theoretical derivation was put forward in the paper, which demonstrated that the phase difference between both ends of the line where the center of oscillation located increases with the spread of the power angle of two-sides generator groups and eventually more than 90 degrees; However, the phase difference between both ends of the other lines may increases to a certain extent, not more than 90 degrees, and then decreases rapidly. By using the characteristic of the phase difference with the same trend variation, it can effectively search system oscillation center section and not affected by the operation modes and fault forms of system. The accuracy of the proposed method was verified by both a numerical example of New England 10 machine 39 nodes and a practical example. The simulation results show that the method can accurately grasp the oscillation center of power grid, and has strong adaptability and good practical value.