稳定性判据

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

Paper studies the practical stability of electricity market models by tools, for example, the appropriate structure Lyapunov functions, Cauchy matrix, the matrix measure, constant variation. Judging practical stability sufficient conditions and estimating formula of ultimate convergence boundary are provided. Conditions are descriptive by coefficients of models. At the same time, paper studies the Lyapunov stability of the electricity market. As well as the sufficient conditions of judging electricity market Lyapunov stability are provided. Some of conclusions improved the results of Alvarado and others. The conclusion of Lyapunov stability has made a comparative with practical results.

首次将实用稳定性理论和方法应用于电力市场稳定性的研究中，借助于构造合适的Lyapunov函数、柯西矩阵、矩阵测度、常数变易法等工具，系统研究了所建电力市场模型的实用稳定性，得到了用模型的系数来描述其实用稳定性的一系列判定条件和最终收敛边界的估计公式；同时对电力市场的Lyapunov稳定性进行了研究，得到了电力市场稳定性的若干判据，部分结论改进了Alvarado等人的结果；随后将Lyapunov稳定的结果与实用稳定进行了比较。

In Part 5, the stability of linear large-scale singular dynamic system is investigated by using the method of vector generalized Lyapunov function and the sum type of scalar generalized Lyapunov function, respectively.

首先研究线性广义系统二次型李雅普诺夫函数的存在性；然后建立按线性近似系统决定非线性广义系统稳定性的准则；进而改进广义李雅普诺夫函数法以研究广义系统的稳定性；最后提出利用非线性函数的偏导数矩阵判别非线性微分-代数系统稳定性的若干简便判据。

Secondly, we consider the stability problem of a more widespread class of feedback interconnected system, which can allow the nonlinear operator to have a deviation. And some stability criteria are presented too.

并将其应用于绝对稳定性问题，得到了时变的圆判据，也给出了多输入多输出情况下的一些判据，这些结果对非线性环节是否解耦不作要求。

Several important concepts in robust design such as robust stability, robust performance,μ-stability and quadratic stability are studied. The conservatism in each robust test is also given.

对鲁棒稳定性、鲁棒性能，如μ-稳定性和二次型稳定性等控制系统鲁棒设计中的一些重要概念和相应的判据进行了研究，分析了它们的保守性。

A simple form of the unstable manifold s for the fixed points not being on the boundary;2. Aim To study singular points, closed orbits, stable manifolds and unstable manifold s of a second order autonomous Birkhoff system.

目的研究二阶Birkhoff自治系统的奇点、闭轨、稳定流形与不稳定流形，方法用常1微分方程的定性方法进行研究，结果与结论给出二阶Birkhoff自治系统的奇点判据、闭轨判据、双曲平衡点判据，得到与其相关的平衡稳定性、稳定流形与不稳定流形等。

A torsional oscillation observer based on the general observer was discussed to estimate the speed of the turbine generator. The dynamic characteristics of standard Luenberger observer with quantization effects were studied by Lyapunov stability criterion. It is concluded that the state estimate error can not asymptotically converge to zero in-the-large in presence of quantization effects.

讨论了基于状态观测器的汽轮机轴系扭振测量方法，采用李亚普诺夫稳定性判据分析存在量化效应的条件下标准龙贝格观测器的动态特性，指出由于数字系统中的有限字长效应会使观测器的跟踪性能恶化，估计误差不能在大范围内渐进收敛。

The criterion of stability and formula of the criti-cal rotative velocity obtained just is the same as that of the linear theory ofContensour-Magnus complately.

所得的稳定性判据及临界转速的表达式与Contensou-Magnus线性理论完全相同。

A theory of optimum design for feedback line and a stability criterion for load sensing variable displacement pump are but forward.

第五章对试验中所发现的两个问题做了深入的理论分析和仿真研究，针对反馈油路和负载敏感变量泵提出了一套优化设计理论和稳定性判据。

A new Criterion-the maximum energy ratio criterion was suggested to evalate the relative stability of rotor bearing systems. The contribution of each bearing to system stability was investigated.

由于几种常用的评估系统稳定性好坏的判据存在某些不足，促使作者对这一问题进行了探索性的研究，提出了以最大能量比率作为衡量系统稳定性好坏的判据。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。