共查询到20条相似文献,搜索用时 250 毫秒
1.
本文构造了一类多变量非线性控制系统新的李雅普诺夫函数,并将它用于电力系统稳定性分析,得到了单机无穷大系统、多机系统的改进型李雅普诺夫函数。计算例题表明:该类型李雅鲁诺夫函数和传统的Lure型李雅普诺夫函数相比,能更准确地给出电力系统暂态稳定域。 相似文献
2.
3.
董素玲 《电力电容器与无功补偿》2016,(4):105-110
研究了一种应用于背靠背三电平VSC-HVDC系统的非线性反演控制策略,解决了传统PI线性控制策略存在的动态响应缓慢、系统再稳定恢复时间长等问题。根据李雅普诺夫稳定性定理,构造了李雅普诺夫函数,分别设计了非线性母线电压和内环电流控制器。仿真实验结果表明,当电网功率扰动或潮流反转时,反演控制较传统PI控制具有更加优越的动、稳态性能,同时也大大减小了母线电压和电容电压的暂态纹波。 相似文献
4.
5.
永磁同步电动机的混沌同步控制 总被引:1,自引:0,他引:1
根据反推控制原理设计了一种永磁同步电动机的混沌同步控制。基于永磁同步电动机的数学模型,把两个系统构成的误差系统分解成几个子系统,为每个子系统设计李雅普诺夫函数(Lyapunov)和中间虚拟控制量。根据李雅普诺夫函数得出控制器使得误差系统最后趋向零。仿真结果表明该方法有效可行。 相似文献
6.
阐述了电力系统励磁控制系统目标全息反馈的方法,将系统中非线性因素转换到含有控制输入的状态方程中.提出了李雅普诺夫函数函数,对应的滑模控制器保证了全局收敛性;设计了扩张状态观测器,使系统能够实时跟踪并补偿扰动,使设计的控制器具有自适应性.MATLAB的仿真结果证明了该方法的有效性. 相似文献
7.
直流微电网运行稳定性是近几年来微电网研究领域的重点课题之一.针对直流微电网非线性特点,提出了采用李雅普诺夫方法来进行系统稳定性分析.首先,介绍了直流微电网发展背景并对比分析了其他研究成果;其次,建立了直流微电网模型,给出了状态空间方程来表征非线性直流微电网;在此基础上用李雅普诺夫直接法详细分析证明了所搭建系统的稳定性,通过证明过程确定了系统稳定性约束条件;最后,在MATLAB/Sim-ulink环境下对直流微电网模型实例进行仿真,仿真结果与理论分析在平衡点处有较好的一致,证明了所提出的李雅普诺夫方法在直流微电网稳定性分析中的有效性与正确性. 相似文献
8.
对于带锁相环的并网VSC大扰动稳定性问题,首先依据VSC的内环电流控制和外环功率控制响应速度差异得到简化二阶非线性模型,然后分别定义了两个李雅普诺夫函数。第一个李雅普诺夫函数具有清晰的动能和势能概念,但推导的稳定域较小,第二个李雅普诺夫函数推导的稳定域较大但缺乏清晰的物理概念。最后结合这两个李雅普诺夫函数,得到实用的稳定性判据,兼具明确的物理意义和较宽的稳定域。如果在系统最后一次动作时已知锁相环状态量,则可以预测系统稳定性。仿真结果验证了该判据的正确性。 相似文献
9.
10.
采用李雅普诺夫函数法,设计了一个信号综合形式的模型参考自适应控制器,该控制器算法简单,易于微机实现,文中给出了部分实验结果。 相似文献
11.
Liu Yu-sheng Chen Jiang Li Xing-yuan 《Frontiers of Electrical and Electronic Engineering in China》2006,1(3):259-264
Many physical systems such as biochemical processes and machines with friction are of nonlinearly parameterized systems with
uncertainties. How to control such systems effectively is one of the most challenging problems. This paper presents a robust
adaptive controller for a significant class of nonlinearly parameterized systems. The controller can be used in cases where
there exist parameter and nonlinear uncertainties, unmodeled dynamics and unknown bounded disturbances. The design of the
controller is based on the control Lyapunov function method. A dynamic signal is introduced and adaptive nonlinear damping
terms are used to restrain the effects of unmodeled dynamics, nonlinear uncertainties and unknown bounded disturbances. The
backstepping procedure is employed to overcome the complexity in the design. With the proposed method, the estimation of the
unknown parameters of the system is not required and there is only one adaptive parameter no matter how high the order of
the system is and how many unknown parameters there are. It is proved theoretically that the proposed robust adaptive control
scheme guarantees the stability of nonlinearly parameterized system. Furthermore, all the states approach the equilibrium
in arbitrary precision by choosing some design constants appropriately. Simulation results illustrate the effectiveness of
the proposed robust adaptive controller.
__________
Translated from Journal of Sichuan University (Engineering Science Edition), 2005, 37(5): 148–153 (in Chinese) 相似文献
12.
13.
14.
采用模糊神经网络作为非线性逼近器,针对一类一阶非线性多入多出系统,提出了一种具有扰动抑制的鲁棒自适应控制方法,给出了高阶多入多出系统具有扰动抑制的自适应后推(backstepping)设计方法。在鲁棒项合理简化的情况下,给出了系统Lyapunov意义下的稳定性证明,简略分析了各设计参数的物理意义及其对系统性能的影响。理论分析和仿真实验均显示,本方法可以保证系统的全局渐近稳定性,且若选取恰当的设计参数可保证系统对输入信号的跟踪达到任意精度;由于鲁棒项的引入可使系统的设计更具灵活性。 相似文献
15.
16.
Mengru Liu Weihai Zhang Limin Ma 《International Journal of Adaptive Control and Signal Processing》2022,36(1):69-87
The article investigates the finite-time adaptive fuzzy control for a class of nonlinear systems with output constraint and input dead-zone. First, by skillfully combining the barrier Lyapunov function, backstepping design method, and finite-time control theory, a novel adaptive state-feedback tracking controller is constructed, and the output constraint of the nonlinear system is not violated. Second, the fuzzy logic system is used to approximate unknown function in the nonlinear system. Third, the finite-time command filter is introduced to avoid the problem of “complexity explosion” caused by repeated differentiations of the virtual control signal in conventional backstepping control schemes. Meanwhile, a new saturation function is added in the compensating signal for filter error to improve control accuracy. Finally, based on Lyapunov stability analysis, all the signals of the closed-loop are proved to be semi-globally uniformly ultimately bounded, and the tracking error converges to a small neighborhood region of the origin in a finite time. A simulation example is presented to demonstrate the effectiveness for the proposed control scheme. 相似文献
17.
基于动态面控制的间接自适应神经网络块控制 总被引:1,自引:0,他引:1
针对一类可转化为"标准块控制形"的多输入多输出的非线性系统,基于动态面控制技术,提出一种间接自适应神经网络控制器的设计方案.该方法通过引入1阶滤波器,消除了后推设计中由于反复对虚拟控制的求导而导致的复杂性问题,同时完全避免了反馈线性化方法中可能出现的控制器奇异性问题,且无需控制增益矩阵正定、可逆的条件.利用李亚普诺夫方法,证明了闭环系统是半全局一致终结有界,通过适当选取设计常数,跟踪误差可收敛到原点的一个小邻域内.仿真结果表明所提控制方法的有效性. 相似文献
18.
Indirect adaptive fuzzy control for input and output constrained nonlinear systems using a barrier Lyapunov function 下载免费PDF全文
Yongming Li Tieshan Li Xingjian Jing 《International Journal of Adaptive Control and Signal Processing》2014,28(2):184-199
In this paper, a novel indirect adaptive fuzzy controller is proposed for a class of uncertain nonlinear systems with input and output constrains. To address output and input constraints, a barrier Lyapunov function and an auxiliary design system are employed, respectively. The proposed approach is explored by employing fuzzy logic systems to tackle unknown nonlinear functions and combining the adaptive backstepping technique with adaptive fuzzy control design. Especially, the number of the online learning parameters are reduced to 2n in the closed‐loop system. It is proved that the proposed control approach can guarantee that all the signals in the closed‐loop system are bounded, and the input and output constraints are circumvented simultaneously. A numerical example with comparisons is provided to illustrate the effectiveness of the proposed approach. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
19.
不确定性电力系统鲁棒自适应励磁控制 总被引:3,自引:0,他引:3
为降低电力系统不确定参数和外部干扰在建模和控制设计中对系统品质的影响,利用Backstepping方法,递归构造闭环系统耗散不等式的能量存储函数,进而得到具有干扰抑制的反馈控制.推证了存储函数又是Lyapunov函数,保证闭环系统渐进稳定.设计过程用估计值代替不确定参数,故系统对不确定参数具有适应能力.仿真结果表明,该... 相似文献