The sib of differential - algebra equation ( dae ) can be interpreted as one mechanism of transient voltage unstable or voltage collapse , and this mechanism is illustrated under multi - machine system . moreover , the algorithm for search sib point under multi - machine system is proposed . the study of dae model and its singularity - perturbed model shows that they are different in essence 微分-代数方程下的奇异诱导分岔可作为暂态电压崩溃的一种机理解释，在典型系统中详细地分析了该机理，并在多机系统中构造出相应的算例，此外还提出了在多机系统中计算奇异诱导分岔点的算法设想。
In this thesis , by the summarizing and analyzing about the present stability control study state of synchronous generator unit , it is achieved that the governor pss ( gpss ) is more suitable for the stability control of multi - machine system because of its better decoupled character than conventional pss ; the intelligence control theory is more reasonable than conventional methods to design the hydro - generator unit gpss because of the uncertainty of mathematical model of hydro - electricity system caused by intense nonlinear character and time - variant operating mode of hydro - turbine and water - hammer effect of hydraulic system 本文对同步发电机组稳定控制的研究现状进行了综述和分析。认为：与常规pss相比，调速器侧pss ( gpss )具有良好的解耦特性，更宜用于多机系统的稳定控制；由于水轮机特性的强非线性、工况的时变性以及引水系统的水击效应所导致的水电系统数学模型的不确定性，采用智能控制理论设计水电机组gpss较常规设计方法更为合理。
Based on the electromechanical coupling characteristic of the multi - machine power system , the transitive closure is calculated depending on the synchronization torque coefficient matrix . then a proper threshold value is chosen to achieve the reasonable block decoupling of multi - machine power system . eigenvalues of block - decoupling subsystem are calculated respectively 该方法根据多机电力系统的机电耦合特性，在多机系统同步力矩系数矩阵的基础上，求取传递闭包，通过选择适当的阈值水平，实现多机系统的合理分块解耦；对各分块解耦子系统分别计算特征值，各子系统的特征值的集合可以近似作为原多机系统的特征值。
It is means that gahc would be harmless to the stability of other generators , when it is used to reduce the ste of local generator . the simulating tests of gahc used on steam turbine and hydro turbine had been done in single machine system and multi - machine system . the results of simulating tests show that the generator stability could be improved by gahc , it is harmless to the stability of other generators in multi - machine system 在单机系统和三机无穷大系统中对汽轮发电机和水轮发电机的gahc控制进行了仿真实验，仿真实验结果验证了： gahc提高了汽轮发电机和水轮发电机抵抗三相短路故障扰动冲击的能力； gahc在多机系统中对其它发电机的稳定性不会产生危害作用；水轮机的gahc克服了水锤效应对稳定性的危害作用。
The surplus transient energy , ( ste ) , produced during the fault period is used as the quantity index to evaluate the damage degree of generator stability . the effect of gahc to the generator stability was analyzed in single machine system and multi - machine system . the results of analysis show that ste could be reduced by the gahc , the ste decrease of controlled generator would be helpful to reduce the coupled disturbance transient energy of other generators in multi - machine system 以发电机在故障期间积累的过剩暂态能量作为发电机稳定性受到危害程度的定量评价指标，在单机无穷大系统和多机系统中对gahc提高发电机稳定性的作用机理进行了理论分析，分析结果表明： gahc能够加速被控机组过剩暂态能量的衰减，在多机系统中被控发电机过剩暂态能量的衰减将减少与之关联的其它发电机受到的耦合暂态势能的扰动量，也就说明在多机系统中gahc在提高本地机组稳定性的同时不会对其它发电机的稳定性产生危害作用。
