查询词典 stability

The joint effect of active and reactive power on the voltage stability of a typical power system was considered by analysing the two parameter bifurcation problem related to nonlinear oscillation phenomena. Numerically, as the active power P1 increases, the Hopf points get closer and eventually coincide at P1=1.455 43 the cyclic fold curve gets closer and closer to the Hopf curve and finally intersects the Hopf curve at a singular point the period-doubling points also get closer and finally coincide at P1≈0.65. The stability behaviour is pre-determined using the normal form approach near the limit point of the Hopf curve. Hence, in the power system attention should be paid to both the consumption of active power and the decrease in the reactive power to prevent nonlinear oscillations. A controller can be designed to absorb some active power and to avoid the nonlinear oscillations that damage the system components.

针对一个典型的单机无穷大电力系统，通过分析系统的双参数分岔的非线性振荡现象，综合考虑有功和无功功率对电压稳定性的影响数值分析表明，随着有功功率的增加，电力系统的Hopf点越来越靠近，最终合为一点在P1=1.455 43处同时圈折cyclic fold 曲线也越来越靠近Hopf曲线，并在Hopf曲线的稳定与不稳定临界点处与Hopf曲线相交倍周期分岔点也随着越来越靠近，最终在P1≈0.65 合为一点应用正规形理论方法，初步确定了Hopf曲线极限点附近的稳定性态因而，电力系统应注意让负荷利用有功功率，减少无功功率的产生以防止非线性振荡另外，可以设计一个稍微吸收网络的有功功率的控制器，以避免因周期振荡而造成电力系统仪器的损坏或电压崩溃

Judging stability of critical nonlinear systems is a basic problem of systems stability.

临界非线性系统的稳定性判别是稳定性研究的一个基本课题。

It could display only when exposed to disturbance which causes the degradation of ecosystem however it is impacted by natural or nonnatural factors. The concepts of fragility and stability, the fragility in relation to species invasion and extriction, to diversity and stability of ecosystem, to primary productivity, to niche differentiation as well as to microclimatic change of ecosystem are discussed....

而干扰（包括自然干扰和人为干扰）又是引起退化生态系统的原因，种类的入侵和消亡、种类组成的变化、生态系统的多样性和稳定性、生产力、生态位的分化及生态系统小环境变化则是研究退化生态系统形成和恢复的重要内容，本文探讨脆弱性与退化生态系统诸方面的关系以及在植被恢复上的应用。

The sufficient conditions to guarantee robust exponential stability for the closed-loop systems are obtained based on Linear Matrix Inequality, moreover, the approach of design of robust H# output feedback controller is introduced.3 The problem of reliable H# control for a class of Lur"e systems with polytopic uncertainties is studied when all control components are operational as well as when some control components experience failures, the design approach of reliable H# controller is also obtained.4 Considering a class of uncertain Lur"e singular system with time-delays, the problem of robust stability is investigated based on Barbalats Lemma and nonsingular linear transformation of model reduction.

针对一类不确定Lur'e奇异时滞系统，基于Barbalat引理以及非奇异降阶变换，讨论了Lur'e奇异时滞系统的鲁棒稳定问题，提出了鲁棒H_∞状态浙江大学博士学位论文反馈控制器的设计方法。5、针对一类具有饱和执行器的不确定Lur'e奇异系统，提出了时滞依赖的鲁棒稳定与鲁棒二次镇定的充分条件，所的结果不需要参数的整定。6、针对任意协方差有界的有色噪声，讨论了一类不确定Lur'e奇异系统的鲁棒凡滤波问题，得出了鲁棒几滤波器设计的充分条件。7、针对一类不确定Lur'e时滞系统，通过线性变换，把它转换成奇异系统，根据奇异系统鲁棒控制理论所得出的鲁棒稳定与鲁棒镇定控制器设计的充分条件具有很小的保守性。

This paper introduces the practice of applying normalized transient energy function for transient stability assessment in Henan power network with transient stability control.

介绍考虑稳定控制措施后的归一化能量函数在河南电网暂态稳定性分析中的应用。

Normalized transient energy function ; transient stability assessment ; stability control

归一化能量函数；暂态稳定性；稳定控制

The nuclear force can maintain the stability of a nuclei so that it can also maintain the stability of the neutron stars.

这种短程力能使原子核保持稳定，当然也能使带电中子星保持稳定。

It is a matter of great significance to make fast and exactly transient stability analysis for power system security and stability, the main analysis method is numerical integration.

暂态稳定性的快速正确评估，对于电力系统的安全稳定运行具有重要的意义。

Both the results for the numerical stability and the methods used in the stability analysis of the paper are new and valuable.

在随机延迟微分方程数值方法的稳定性研究中，无论是本文中得到的稳定性结论还是分析问题时使用的方法都是全新的，因此具有一定的价值。

Objective To analyze occlusive factors on stability of denture plantation and investigate the method to maintain long-term stability of implants.

目的 分析影响种植义齿稳定性的咬合因素，保持种植体的长期稳定。

However it can often be frust ating for a child when people are unable to pronounce their name.

但它往往可以令人沮丧的一个孩子当人们无法断言他们的名字。

All these compounds were obtained from this genus for the first time. Compound, 4-cumylphenol, was a new nature product.

所有化合物均为首次从本属海藻中分离得到，其中4cumylphenol为新天然产物。