基于Lyapunov函数的非线性励磁控制器设计

针对单机无穷大电力系统,将Lyapunov(李亚普诺夫)稳定性理论应用于电力系统的非线性励磁控制,提出了一种实用的发电机非线性优化鲁棒励磁控制律.仿真结果表明,设计的励磁控制器不仅可提高系统的鲁棒性,抑制干扰对系统的影响,而且提高了励磁控制系统的反应速度,改善了电力系统的动态性能.     

一类切换T-S型模糊系统二次镇定保成本控制

针对一类不确定切换T-S型模糊系统,对保成本鲁棒控制问题进行了研究。利用单Lyapunov函数法,给出了混杂状态反馈保成本控制器的设计方案,使得闭环系统对所有允许的不确定性,在所设计的混杂状态反馈控制器下是二次稳定的,应用线性矩阵不等式的可解性给出闭环系统二次稳定的充分条件,同时给出了二次型成本函数的一个上界。模型中的每个切换系统的子系统是不确定模糊系统,取常用的平行分布补偿PDC控制器,主要条件以凸组合的形式给出,具有较强的可解性。仿真结果验证了所设计方法的有效性。     

一类切换系统的动态输出反馈控制器设计

针对一类非线性扰动项不满足匹配条件的蚤确定切换系统鲁棒动态输出反馈镇定问题,采用单李雅普诺夫函数方法和变量替换方法,研究了状态矩阵和控制输入矩阵同时带有未知、时变但有界的不确定性,且有外界干扰的切换系统,给出了不确定切换系统鲁棒可稳的充分备件。仿真结果表明,所设计的动态输出反馈控制器及相应的切换策略保证了闭环系统渐近稳定。     

基于Lyapunov函数的永磁同步电机速度控制器设计

传统的PI速度控制器具有速度超调、动态时间长、跟踪精度低、抗负载转矩扰动能力和恢复能力差等缺点。提出了利用永磁同步电机(PMSM)的运动方程和转矩方程推导出控制系统q轴电流给定量,基于Lyapunov稳定性条件设计出的一种PMSM速度控制器。相比于传统的PI速度控制器,该控制器没有速度超调量、动态时间短、跟踪精度高,抗负载扰动能力和恢复能力有一定的提高。利用MATLAB/Simulink仿真软件,搭建控制系统模型并进行仿真分析。仿真验证了提出的PMSM速度控制器的有效性,获得了很好的速度控制性能。     

一类切换线性中立时滞系统稳定性的分析

提出了切换中立时滞系统的概念.研究了线性切换中立时滞系统渐近稳定性问题,并分别利用单Lyapunov函数法和多Lyapunov函数法,以线性矩阵不等式的形式分别给出一类切换线性中立时滞系统渐近稳定的充分条件及切换律的设计.然后假设存在有限个备选的控制增益已知的控制器,并在任何单一的状态反馈控制器都不能镇定系统时,设计该类系统的混杂状态反馈控制器,使闭环系统渐近稳定.最后用部分元件等效电路（PEEC）的仿真例子验证了结论的有效性.     

带有多胞型摄动的线性切换系统的二次稳定性

研究了带有多胞型摄动的线性切换系统的二次稳定性问题。这种摄动是由若干已知常数矩阵所张成的多胞构成的。利用完备性给出二次稳定的充要条件和切换律的设计方法,利用凸组合技术给出了二次稳定的一个充分条件。这些方法能够分析含有不稳定子系统的多胞型切换系统的稳定性。仿真例子说明了文中结果的正确性。     

基于Lyapunov函数的全数字锁相环的优化设计

对三相输入电压畸变条件下的矢量型数字锁相环工作原理及其非线性动态模型进行了研究,给出了一种基于Lyapunov函数的具有高稳定性和相位跟踪能力的三相数字PLL的设计方法。对环路滤波控制器和具有自动复位功能的压控振荡器分别进行离散化,解决了数字化过程中处理器有限字长的问题。对三相输入相不平衡、谐波、偏移等畸变条件下的PLL误差进行了计算和分析,采用PI控制器取代传统的环路滤波器,提高了三相数字锁相环抑制畸变的能力和跟踪响应的速度。采用DSP实现三相数字锁相环技术,并用于6kW逆变器功率因数的控制中,仿真和实验均验证了理论分析的正确性。     

一类不确定线性切换系统的二次鲁棒稳定性

为了研究一类线性切换系统及其带有非线性扰动系统在任意切换律下的二次鲁棒稳定性问题,采用Riccati不等式导出了带有时变扰动的在任意切换律下二次鲁棒稳定的充分条件,利用线性矩阵不等式研究了其带非线性扰动项的系统在任意切换律下的二次鲁棒稳定的充分条件,并用数值例子对所得结果加以仿真。结果表明,所得的结果是正确的。     

一种新的Lyapunov函数及其大规模动态系统稳定性分析

本文构造了一个新的Lyapunov函数,提出了大规模电力系统暂态稳定分析方法和稳定判据。用该方法对一个试验电力系统进行了模拟计算,结果是令人满意的,保守住得到了很大的改进,有较好的实用价值。     

方块脉冲函数用于动态系统辨识

应用方块脉冲函数系给出了一个动态系统辨识的新方法，方法应用到单输入单输出系统中，而且证明了精度以及收敛性。     

Robust controller for a class of uncertain switched fuzzy systems

A robustness control of uncertain switched fuzzy systems is presented. Using the switching technique and the Lyapunov function method, a continuous state feedback controller is built to ensure that for all allowable uncertainties the relevant closed-loop system is asymptotically stable. Furthermore, a switching strategy that achieves system global asymptotic stability of the uncertain switched fuzzy system is given. In this model, each subsystem of the switched system is an uncertain fuzzy system, and a common parallel distributed compensation controller is presented. The main condition is given in the form of convex combinations which are more solvable. This method transforms a certain switched system and has strong robustness for various system parameters. Simulations show the feasibility and the effectiveness of this method. Translated from Journal of Northeastern University, 2006, 27(7): 713–715 [译自: 东北大学学报 (自然科学版)]     

Stabilization of switching Takagi–Sugeno systems by switched Lyapunov function

This paper presents sufficient conditions for the stabilization of switching T‐S fuzzy discrete‐time linear systems. These conditions are obtained when state feedback control laws are used. The obtained results are formulated in terms of LMIs. A numerical example illustrates the technique. Copyright © 2011 John Wiley & Sons, Ltd.     

Adaptive state tracking of switched systems based on a hyperstability criterion

The adaptive state tracking problem of switched systems is studied in this paper. The desirable state trajectory is generated by a switched reference model. First, a condition for asymptotical hyperstability of switched systems is proposed and a switching law is designed, which is a generalization of the classical hyperstability condition for non‐switched systems. Then, the result is applied to uncertain switched systems to achieve state tracking. An individual adaptive law is designed for each subsystem such that the Popov inequality is satisfied. Asymptotical state tracking is achieved under non‐persistent exciting input when the error system switches in a certain way. The result is demonstrated by a numerical example and a practical system of Highly Maneuverable Aircraft Technology vehicle, respectively. Copyright © 2013 John Wiley & Sons, Ltd.     

Switched adaptive stabilization of switched nonlinearly parameterized cascade systems and its application to a two inverted pendulums

This paper studies adaptive control of switched nonlinearly parameterized cascade systems. No solvability of the adaptive control problem for subsystems is required. By exploiting the multiple Lyapunov functions method and the parameter separation technique and the tool of adding a power integrator, we develop a new switched adaptive control approach for the explicit construction of adaptive controllers of subsystems and a proper switching law that solves the adaptive stabilization problem. A key feature of the proposed adaptive controllers is its switched property, namely, each subsystem has its individual update law. A two‐inverted pendulum as a practical example is also provided to demonstrate the effectiveness of the proposed design method. Copyright © 2014 John Wiley & Sons, Ltd.     

Fuzzy adaptive optimal control for nonlinear switched systems with actuator hysteresis

This article considers the issue of fuzzy adaptive dynamic programming control of nonlinear switched systems with arbitrary switchings and unknown uncertain functions and actuator hysteresis nonlinearities. The whole control approach is made of switching feedforward controller and optimal switching feedback controller. To get over the hardness of arbitrary switching structure and the issue of “explosion of complexity”, the common Lyapunov function theory and dynamic surface control method are utilized in the recursive design technique. By using fuzzy logic systems to model unknown inner dynamics and unknown cost functions, a novel fuzzy adaptive optimal switching control strategy is developed. Meanwhile, uniformly ultimately boundedness of all weights in the controlled systems are proved by the proposed control method, and the tracking performance is guaranteed in an optimal manner. Subsequently, a numerical simulation study is used to test the effectiveness of the presented control strategy.     

Design of controllers for a class of switched nonlinear systems based on backstepping method

The backstepping method is applied to a certain class of switched nonlinear systems to design state feedback controllers and a switching law based on multi-Lyapunov functions. The state feedback controllers and the switching law that can stabilize the system are developed. The switched nonlinear systems with uncertainties can be stabilized robustly by using the proposedmethod. Finally, simulation results show the effectiveness of the method. __________ Translated from Control and Decision, 2007, 22(12): 1373–1376 [译自: 控制与决策]     

An adaptive design for quantized feedback control of uncertain switched linear systems

This paper addresses the problem of asymptotic tracking for switched linear systems with parametric uncertainties and dwell‐time switching, when input measurements are quantized due to the presence of a communication network closing the control loop. The problem is solved via a dynamic quantizer with dynamic offset that, embedded in a model reference adaptive control framework, allows the design of the adaptive adjustments for the control parameters and for the dynamic range and dynamic offset of the quantizer. The overall design is carried out via a Lyapunov‐based zooming procedure, whose main feature is overcoming the need for zooming out at every switching instant, in order to compensate for the possible increment of the Lyapunov function at the switching instants. It is proven analytically that the resulting adjustments guarantee asymptotic state tracking. The proposed quantized adaptive control is applied to the piecewise linear model of the NASA Generic Transport Model aircraft linearized at multiple operating points.