关于轨迹分析方法中的稳定指标S1在单机系统中性质的证明

给出了一种新的用于分析单机无穷大电力系统暂态稳定性的时域模型。在此基础上证明了轨 迹分析方法所给出的稳定指标S1在各种恶化稳定方式下均具有单调下降性。从而说明在单机 系统中指标S1能定量地反映发电机的暂态稳定状况，因此S1作为稳定指标是有效的。而稳定 指标S1仅由系统运动的轨迹信息即可算出，其定义不依赖于任何临界能量。因此这种稳定指 标很适用于常规电力系统暂态稳定程序的输出分析中。

PROOF OF SOME THEOREMS ON THE STABILITY INDEX PROVIDING BY THE TRAJECTORY ANALYSIS METHOD IN AN OMIB POWER SYSTEM

A new OMIB power system model -time domain model for analyzing transient stability, has been proposed in this paper. Based on the model, some theorems on the stability index S1 providing by the Trajectory Analysis Method have been proved. They show that whenever the transient stability being deteriorated the value of S1 is monotonically decreased, so S] is valid as a stability index of the system. The definition of index S1 only depends upon the trajectory information of the system, it never depends upon any critical energy. So the calculation of S1 is very simple and it is suitable for use in the transient stability program output analysis.