电力系统混沌振荡的等效快速终端模糊滑模控制

电力系统混沌振荡被认为是大型互联电力系统停电事故的主要原因, 本文通过相图、 李雅普诺夫指数图和时域波形图分析了二阶电力系统混沌振荡的动力学行为, 并提出了等效快速终端模糊滑模控制来抑制电力系统混沌振荡, 使其恢复到同步运行状态. 仿真结果表明, 所提出的控制方案不仅具有较快的收敛速度, 而且能够柔化控制信号, 减少控制能量, 并且能有效地降低抖振. 关键词： 电力系统混沌振荡 等效滑模控制 模糊滑模控制 快速终端滑模控制     

基于继电特性函数的互联电力系统混沌控制

电力系统中的混沌振荡对整个互联电网具有极大危害.本文利用Lyapunov指数、分岔图、相平面图和功率谱等分析一个简单互联电力系统的动力学行为,研究电力系统对电磁功率扰动幅值的敏感性.同时,提出一种基于继电特性函数的准滑动模态控制方法,对系统进行混沌振荡抑制,使系统快速平滑地到达控制目标.实验表明,该方法不仅能够缩短控制时间,减少因参数过大带来的系统冲击,而且对高频抖动也有很好的抑制作用,具有较强的鲁棒性.     

Dynamic analysis and fractional-order adaptive sliding mode control for a novel fractional-order ferroresonance system

Ferroresonance is a complex nonlinear electrotechnical phenomenon, which can result in thermal and electrical stresses on the electric power system equipments due to the over voltages and over currents it generates. The prediction or determination of ferroresonance depends mainly on the accuracy of the model used. Fractional-order models are more accurate than the integer-order models. In this paper, a fractional-order ferroresonance model is proposed. The influence of the order on the dynamic behaviors of this fractional-order system under different parameters n and F is investigated.Compared with the integral-order ferroresonance system, small change of the order not only affects the dynamic behavior of the system, but also significantly affects the harmonic components of the system. Then the fractional-order ferroresonance system is implemented by nonlinear circuit emulator. Finally, a fractional-order adaptive sliding mode control(FASMC)method is used to eliminate the abnormal operation state of power system. Since the introduction of the fractional-order sliding mode surface and the adaptive factor, the robustness and disturbance rejection of the controlled system are enhanced. Numerical simulation results demonstrate that the proposed FASMC controller works well for suppression of ferroresonance over voltage.     

Fixed time integral sliding mode controller and its application to the suppression of chaotic oscillation in power system

Chattering phenomenon and singularity are still the main problems that hinder the practical application of sliding mode control. In this paper, a fixed time integral sliding mode controller is designed based on fixed time stability theory,which ensures precise convergence of the state variables of controlled system, and overcomes the drawback of convergence time growing unboundedly as the initial value increases in finite time controller. It makes the controlled system converge to the control objective within a fixed time bounded by a constant as the initial value grows, and convergence time can be changed by adjusting parameters of controllers properly. Compared with other fixed time controllers, the fixed time integral sliding mode controller proposed in this paper achieves chattering-free control, and integral expression is used to avoid singularity generated by derivation. Finally, the controller is used to stabilize four-order chaotic power system. The results demonstrate that the controller realizes the non-singular chattering-free control of chaotic oscillation in the power system and guarantees the fixed time convergence of state variables, which shows its higher superiority than other finite time controllers.     

受扰统一混沌系统基于RBF网络的主动滑模控制

针对受外扰影响的统一混沌系统,提出一种基于径向基函数(RBF)神经网络的主动滑模自适应控制方法.将被控系统分解为受控子系统和自由子系统,利用主动控制思想,建立受控子系统在目标点处的状态误差的可控标准型,设计出一个结构简单的基于滑模趋近率在线参数整定的RBF函数神经网络控制器,并且基于Lyapunov稳定性理论分析了系统的稳定性.仿真结果表明该控制器对系统参数突变和外部干扰具有鲁棒性,同时抑制了抖振. 关键词： 统一混沌系统 主动控制 滑模控制 RBF网络     

Finite-time modified combination synchronization of memristive FitzHugh–Nagumo circuit with unknown disturbances

The memristor-based FitzHugh-Nagumo neuron system shows special dynamical behaviors, which make it have a good application in the fields of image processing and signal transmission. The accurate dimensionality reduction model of the system is established, which facilitates the internal interpretation and physical control of the multistability that depends on the initial values. The dynamical behavior analyses of the dimensionality reduction memristive system with different original initial states are developed through bifurcation diagram and Lyapunov index spectrum. Multistability and antimonotonicity with periodic-chaotic bubbles are investigated. The sliding mode control method with a smooth function is designed to achieve the finite-time synchronization of the multistable memristive neuron systems, which make three different behaviors of systems synchronized. The sliding mode controller can enable the system to quickly and smoothly implement combination synchronization within finite time. Numerical simulations show the effectiveness of the sliding mode controller designed.     

浮球式惯导平台悬浮稳定问题的动力学建模与控制

以浮球式惯导平台的悬浮稳定为研究对象, 全面分析了平台的干扰特性, 建立了液浮支撑模型, 推导了在受扰条件下稳定部件的六自由度运动方程. 针对外部环境、流场阻力、模型参数不确定、未建模动态和测量噪声等干扰问题, 设计了基于高增益扩张观测器的滑模控制器. 数值仿真表明, 液浮稳定结构可以有效隔离外界干扰的影响, 提高平台的抗干扰能力; 所提出的控制方法可以有效抑制系统的抖振, 实现平台的高精度快速稳定控制. 与前期的研究相比, 控制器的动态响应和稳定性能提升了50%. 关键词： 浮球式惯导平台 悬浮稳定 高增益扩张观测器 滑模控制     

Controlling chaos based on a novel intelligent integral terminal sliding mode control in a rod-type plasma torch

An integral terminal sliding mode controller is proposed in order to control chaos in a rod-type plasma torch system.In this method, a new sliding surface is defined based on a combination of the conventional sliding surface in terminal sliding mode control and a nonlinear function of the integral of the system states. It is assumed that the dynamics of a chaotic system are unknown and also the system is exposed to disturbance and unstructured uncertainty. To achieve a chattering-free and high-speed response for such an unknown system, an adaptive neuro-fuzzy inference system is utilized in the next step to approximate the unknown part of the nonlinear dynamics. Then, the proposed integral terminal sliding mode controller stabilizes the approximated system based on Lyapunov's stability theory. In addition, a Bee algorithm is used to select the coefficients of integral terminal sliding mode controller to improve the performance of the proposed method. Simulation results demonstrate the improvement in the response speed, chattering rejection, transient response,and robustness against uncertainties.     

冠状动脉系统高阶滑模自适应混沌同步设计

针对冠状动脉系统混沌同步问题, 系统模型受到有界但未知的不确定干扰条件下, 利用几何齐次性理论和积分滑模面设计高阶滑模自适应控制器, 使响应系统在有限时间内跟踪驱动系统, 该方法无需提前预知扰动边界. 采用Lyapunov理论对闭环系统进行分析并证明该控制器保证该系统能够在有限时间内镇定, 从仿真实验结果可以看出所设计的控制器在不确定干扰的情况下系统具有良好鲁棒性和未知参数的自适应性, 为能够有效治疗心肌梗死等冠状动脉疾病提供了一定的理论依据.     

飞行模拟转台非线性干扰观测器反步滑模控制器设计

本文针对考虑不确定性的飞行模拟转台伺服系统,提出了一种基于非线性干扰观测器的反步全局滑模补偿控制方法。该方法采用反步控制方法设计转速期望虚拟控制,然后利用非线性干扰观测器观测系统不确定干扰,进而对引入非线性干扰观测器的系统设计自适应全局滑模控制器,实现了飞行模拟转台伺服系统期望转角信号的鲁棒跟踪控制,仿真结果表明,该方法控制效果良好,具有很好的工程应用价值。     

基于脉冲宽度调制的滑模变结构控制的一阶H桥逆变器的分岔和混沌行为研究

滑模变结构控制是一种在宽工作范围具有快速响应和高稳定性的鲁棒控制, 因而被广泛地应用于逆变器控制中. 滑模控制的逆变器本质上是一种由非线性控制方式控制的时变非线性系统, 具有复杂的动力学行为. 本文以基于脉冲宽度调制的滑模变结构控制的一阶H桥逆变器为例, 首先观察不同滑模变结构控制器参数下系统的输出波形, 发现了一种多种倍数的倍周期同时存在的新型分岔现象; 其次, 使用频闪映射方法建立系统的离散迭代模型, 并利用折叠图法分析输出波形. 通过分析可知系统不能以这种新型分岔为道路通向混沌. 此外, 在工程应用中十分关心系统稳定性, 但是由于滑模变结构控制器的非线性特性, 常规解析方法都已不再适用于对系统进行分析, 而图解法又难以满足精度要求. 因此, 本文提出了一种新的适用于滑模变结构控制的逆变器的快变尺度稳定性的判断依据, 经验证该判据可以准确地判断系统是否处于稳定运行状态, 进而为滑模变结构控制器的参数设计提供可靠依据. 关键词： H桥逆变器 滑模变结构控制 新型分岔 稳定性判据     

基于模糊滑模的有限时间混沌同步实现

提出了混沌同步有限时间实现问题.应用全程滑模控制技术，选择指数型终端滑模趋近律来设计滑模控制器，以实现一类混沌系统的状态同步.该设计方案针对混沌系统的参数不确定性和外界扰动，引入模糊基函数网络，在线估计不确定性和外部扰动的界值.同时该方案消除了滑模控制的到达阶段，状态始终保持在滑模面上，并能在有限时间内趋近于原点.最后以Duffing系统为例研究验证同步策略的可行性和有效性.     

考虑模型不确定性和时延的静止无功补偿器自适应滑膜控制器设计

静止无功补偿器(static var compensator,SVC)不仅可以为电力系统提供无功支撑、稳定电压,其附加控制还可以有效提高系统暂态稳定性,但SVC模型参数的不确定性以及广域测量信号时延等外部干扰给附加控制器的设计带来很大的难度.提出了一种基于自适应滑模变结构理论的SVC鲁棒控制器设计方法,所设计控制器能有效提高系统暂态稳定性,并且其对于模型不确定性以及时延有较好的鲁棒性.首先根据区域惯量中心的运动方程建立了包含SVC的电力系统模型;然后将滑模变结构理论应用于电力系统模型中,求得SVC附加控制律,并通过自适应律优化控制器参数;最后通过四机两区域系统以及IEEE9节点系统对SVC控制器效果进行了仿真验证.结果表明,SVC自适应滑模控制器可以有效提升系统暂态稳定性,并且其性能优于传统的线性控制方法.     

基于径向基函数神经网络的Lorenz混沌系统滑模控制

针对受参数不确定和外扰影响的混沌Lorenz系统，提出一种基于径向基函数（RBF）神经网 络的滑模控制方法.基于被控系统在不稳定平衡点处状态误差的可控规范形，设计滑模切换 面并将其作为神经网络的唯一输入.单入单出形式的RBF控制器隐层只需7个径向基函数，网 络的权值则依滑模趋近条件在线确定.仿真表明该控制器对系统参数突变和外部干扰具有鲁棒性，同时抑制了抖振. 关键词： 混沌控制 滑模 径向基函数神经网络 Lorenz系统     

参数不定的旋转圆盘在有界扰动下混沌振动的滑模变结构控制

为了消除具有不确定参数的旋转圆盘横向混沌振动,克服其对整个系统及工作状况的不利影响,假设作用在旋转圆盘上的集中力不确定且有界,并鉴于干扰的普遍存在性,对有界扰动下的旋转圆盘横向振动的四维非线性方程进行了复杂动力学特征分析,包括相轨迹图、Lyapunov指数和庞加莱映射图,这些特征加深了对其的认识,同时也证明该四维动力系统含有混沌吸引子.为了保证系统控制的鲁棒性,利用滑模变结构法,将旋转圆盘从混沌轨道先后控制到任意固定点和周期轨道,并用MATLAB模拟验证其有效性.结果证明,用滑膜变结构法能够使系统严格地跟 关键词： 旋转圆盘 混沌 滑模变结构控制 有界扰动     

Control of a fractional-order economical system via sliding mode

This paper deals with designing a sliding mode controller (SMC) for a fractional-order chaotic financial system. Using the sliding mode control technique, a sliding surface is determined. The sliding mode control law is derived to make the states of the fractional-order financial system asymptotically stable. The designed control scheme is robust against the system’s uncertainty and guarantees the property of asymptotical stability in the presence of an external disturbance. An illustrative simulation result is given to demonstrate the effectiveness of the proposed sliding mode control design.     

Sliding Mode Control of Fractional-Order Delayed Memristive Chaotic System with Uncertainty and Disturbance

In this paper, a simplest fractional-order delayed memristive chaotic system is proposed in order to control the chaos behaviors via sliding mode control strategy. Firstly, we design a sliding mode control strategy for the fractionalorder system with time delay to make the states of the system asymptotically stable. Then, we obtain theoretical analysis results of the control method using Lyapunov stability theorem which guarantees the asymptotic stability of the noncommensurate order and commensurate order system with and without uncertainty and an external disturbance. Finally,numerical simulations are given to verify that the proposed sliding mode control method can eliminate chaos and stabilize the fractional-order delayed memristive system in a finite time.     

一种新颖的滑模非线性比例积分混沌控制方法

一种新颖的滑模非线性比例积分控制方法（SMNPIC）被提出用于高精度驱动一类时变不确定混沌系统到任意期望轨道。SMNPIC区别于以前的滑模控制技术之处在于滑动模的一个非线性比例积分函数被包含在控制率中，因此不仅稳态误差和高频抖振都被减小，同时鲁棒性和快速性也能被保证。此外，SMNPIC实际上能被作为一类非线性PID控制器，不仅仅跟踪误差及其直到n-1阶微分被考虑，而且跟踪误差的积分也被考虑，因此有比传统PID更多的有用信息能被使用，因此更好的动静态特性能被获得。通过不确定Duffing-Holmes系统的仿真实例证实了SMNPIC用于混沌控制能获得好的性能。     

Synchronization Scheme for Uncertain Chaotic Systems via RBF Neural Network

A sliding mode adaptive synchronization controller is presented with a neural network of radial basis function （RBF） for two chaotic systems. The uncertainty of the synchronization error system is approximated by the RBF neural network. The synchronization controller is given based on the output of the RBF neural network. The proposed controller can make the synchronization error convergent to zero in 5s and can overcome disruption of the uncertainty of the system and the exterior disturbance. Finally, an example is given to illustrate the effectiveness of the proposed synchronization control method.     

Robust sliding mode control for fractional-order chaotic economical system with parameter uncertainty and external disturbance

This paper presents a modified sliding mode control for fractional-order chaotic economical systems with parameter uncertainty and external disturbance. By constructing the suitable sliding mode surface with fractional-order integral, the effective sliding mode controller is designed to realize the asymptotical stability of fractional-order chaotic economical systems. Comparing with the existing results, the main results in this paper are more practical and rigorous. Simulation results show the effectiveness and feasibility of the proposed sliding mode control method.