考虑次要失步机群的大区电网失步解列配置

通过对大规模电网的失步仿真研究发现，当系统失步时失步机群可能会呈现为主要失步机群和次要失步机群2种失步模式。主要失步机群决定着整个大区电网的失步中心断面联络线，而次要失步机群不能决定整个大区电网的失步中心断面联络线。该现象将导致通过捕捉失步断面电压最低点（失步中心）寻找失步断面联络线的方法一般只能将主要失步机群分开，却未必能够将次要失步机群也合理分布到与之同调的机群之中。因此，工程中应结合系统离线仿真分析，尽可能对有可能成为次要失步模式的机组安装失步解列装置，以作为一种后备，防止次要失步模式机组扰动系统，造成事故扩大。

Configuration of Large-scale Power System Out-of-step Separation Considering Minor Out-of-step Generations

Through the simulation analysis of large-scale power system,it is found that the out-of-step generators may behave in two groups,the main out-of-step generator groups and the minor out-of-step generator groups.The main out-of-step generator groups can determine the out-of-step center interface tie-lines of large-scale power system,but the minor out-of-step generator groups cannot.This phenomenon facilitates a method of capturing the out-of-step center interface tie-lines,based on searching the lowest voltage points (center of out-of-step) during the system out-of-step state.By doing so,the main out-of-step generator groups can be identified.But the method maybe fails to split the minor out-of-step generators into the correct coherent out-of-step generator groups.Hence,in engineering practice,the generators which are likely to be in the minor ou-of- step groups should be equipped with the out-of-step separation equipment based on the off-line system analysis.Thus with the backup of the separation devices,further accident will be avoided.