功率大扰动下电压稳定域的研究

Study of Voltage Stability Region of Power Systems Subject to Serious Load Disturbance

电力系统的在线安全监控中，电压稳定域的研究具有重要的意义。在完整考虑各种重要动态机制的基础上，针对功率扰动的情况，对分接头位置和母线电压空间中的电压稳定域和复功率注入空间中的电压稳定域分别进行了研究，在上述空间中分别刻画出了电压稳定域的边界，所研究的时间框架涵盖了电压稳定的暂态与中期的过程。通过大量仿真研究得到了关于电压稳定域边界的一些规律性认识，提出了关于临界功率扰动向量的事实，即可以把各台变压器分接头分别锁定在任一既定位置上，通过仿真来寻找临界功率扰动向量。该经验律的发现可以大大减少注入功率空间中电压稳定临界点搜寻方案组合的数目。同时还发现，注入功率空间中临界功率扰动向量的集合可以使用超平面近似表示，这一结果对电力系统的在线安全监控具有重要的应用价值。

Voltage stability region is of great value for on-line security monitoring, assessment and control of power systems. Based on detailed dynamic model of power systems, the boundary of voltage stability region is depicted in the space of tap-rate n and load voltage V of power systems subject to load power disturbances. The time frame includes transient and mid-term voltage stability. Several beneficial conclusions about voltage stability region both in the n-V space and in injection space are drawn, including a principle on critical load power disturbance vectors. Based on the principle, the tap changer can be locked at any position and the critical power disturbance may be found carrying out simulation once, which tremendously reduces the number of scenarios for searching voltage stability critical points in injection space. It is also found that the set of critical load disturbances in the injection space can be approximately modeled by a hyper-plane, which is meaningful for the application of voltage stability region in power systems.