自适应积分逆推滑模励磁控制研究

电力系统参数摄动和外界干扰等因素对励磁系统影响很大,该文选择易于测量的状态变量建立鲁棒励磁控制系统模型,结合逆推设计方法和自适应滑模控制理论设计励磁控制器。按照逆推设计方法,逐步构造了李亚普诺夫函数,在构造虚拟控制信号时引入误差的积分项;给出阻尼系数的自适应律;设计了新的滑模面,从而得到最终的控制规律,对干扰进行抑制。仿真实验结果表明,系统在动静态响应性能上均优于常规逆推控制,说明这种控制方法能够改善系统的电压和功角稳定性。     

具有谐振抑制功能的新型SVC拓扑设计及控制方法

提出一种新型静止无功补偿器的拓扑结构及相应的控制方法。为了提高装置的补偿性能,引入了重复控制。针对10kV电网系统的10MVA不控整流负载,设计了新型静止无功补偿系统。仿真结果表明:新型静止无功补偿器能有效抑制无源滤波器与电网发生的谐振,具有谐波补偿精度高、响应快的特点,适用于高压大容量无功功率和谐波补偿的场合。     

Adaptive asymptotical tracking controller design for uncertain nonaffine nonlinear system with high‐order mismatched disturbances

In this paper, the problem of anti‐disturbance asymptotical tracking control is studied for nonaffine systems with high‐order mismatched disturbances. The disturbances can be described as polynomial functions, which are first estimated by constructing generalized extended state filter. The nonaffine system is changed into an augmented affine system via introducing an auxiliary integrator. A novel adaptive anti‐disturbance tracking controller is recursively designed, where the disturbance estimation is used for feedforward compensation at each step. A sliding mode differentiator is applied to reduce the computational burden taken by the backstepping method. The boundedness of the closed‐loop system is proved based on Lyapunov stability theory and zero error tracking performance is ensured. Finally, a numerical example is provided to show the effectiveness of the proposed scheme.     

Adaptive neural network command filtered backstepping control of pure‐feedback systems in presence of full state constraints

An adaptive neural network (NN) command filtered backstepping control is proposed for the pure‐feedback system subjected to time‐varying output/stated constraints. By introducing a one‐to‐one nonlinear mapping, the obstacle caused by full stated constraints is conquered. The adaptive control law is constructed by command filtered backstepping technology and radial basis function NNs, where only one learning parameter needs to be updated online. The stability analysis via nonlinear small‐gain theorem shows that all the signals in closed‐loop system are semiglobal uniformly ultimately bounded. The simulation examples demonstrate the effectiveness of the proposed control scheme.     

Composite learning fuzzy synchronization for incommensurate fractional‐order chaotic systems with time‐varying delays

This paper presents a composite learning fuzzy control to synchronize two different uncertain incommensurate fractional‐order time‐varying delayed chaotic systems with unknown external disturbances and mismatched parametric uncertainties via the Takagi‐Sugeno fuzzy method. An adaptive controller together with fractional‐order composite learning laws is designed based on both a parallel distributed compensation technology and a fractional Lyapunov criterion. The boundedness of all variables in the closed‐loop system and the Mittag‐Leffler stability of tracking error can be guaranteed. T‐S fuzzy systems are provided to tackle unknown nonlinear functions. The distinctive features of the proposed approach consist in the following: (1) a supervisory control law is designed to compensate the lumped disturbances; (2) both the prediction error and the tracking error are used to estimate the unknown fuzzy system parameters; (3) parameter convergence can be ensured by an interval excitation condition. Finally, the feasibility of the proposed control strategy is demonstrated throughout an illustrative example.     

基于级联有源滤波器与静止无功补偿器的综合补偿控制方案

级联多电平有源滤波器(CS-APF)与静止无功补偿器(SVC)同时运行存在稳定性及无功补偿控制优化等问题。文中提出一种统一控制策略,结合SVC和CS-APF的功能特点,使SVC对负载正序无功分量及负序分量的补偿进行前馈控制和电网电纳(不包含CS-APF分量)反馈控制;CS-APF对晶闸管相控电抗器(TCR)与电网负载谐波的补偿进行前馈控制,并去除SVC中固定电容分量,进行电网电流反馈控制,同时对SVC无功补偿进行二次优化补偿。另外,提出一种TCR谐波电流预计算方法,根据TCR触发角当前值与电网电压锁相环相位,构建TCR谐波电流,实现对TCR谐波的预计算。仿真和实验研究表明,在该综合控制方案下,SVC与CS-APF控制不存在闭环,系统稳定性高,TCR谐波补偿无滞后,无功补偿响应较快,补偿能力强。     

光伏并网逆变器布谷鸟搜索优化反推控制

针对并网逆变器模型非线性和电网扰动的问题,提出一种基于布谷鸟搜索算法优化反推控制技术光伏并网逆变器控制策略。首先,建立考虑参数变化和电网扰动的并网逆变器数学模型,设计并网逆变器反推控制。然后,利用布谷鸟搜索算法对不确定性部分进行在线辨识和补偿,消除模型非线性和外部扰动产生的不确定性部分的影响。利用Lyapunov稳定性理论设计控制器自适应律,证明了布谷鸟搜索算法优化反推控制器的稳定性。实验结果表明该方法能实现逆变器精确并网控制,具有较好的动静态性能和较强的鲁棒性。     

链式静止同步补偿器自适应反步控制器

针对链式静止同步补偿器(STATCOM)系统非线性特性,提出一种链式STATCOM自适应反步控制器。该控制器采用反步法的递归思想获得链式STATCOM的虚拟控制输入,并根据确定性等价原理设计系统的中间控制率,利用该中间控制率完成电压控制器设计。通过中间控制率和实际控制率的偏差量构造系统的李雅普诺夫方程,利用李雅普诺夫的渐近稳定性原理,获得能够保证链式STATCOM系统稳定的控制输入和系统参数的自适应率。实验结果进一步验证了所设计自适应反步控制器的正确性和有效性。     

Decentralized robust adaptive neural dynamic surface control for multi‐machine excitation systems with static var compensator

Focusing on solving the control problem of the multimachine excitation systems with static var compensator (SVC), this paper proposes a decentralized neural adaptive dynamic surface control (DNADSC) scheme, where the radial basis function neural networks are used to approximate the unknown nonlinear dynamics of the subsystems and compensate the unknown nonlinear interactions. The main advantages of the proposed DNADSC scheme are summarized as follows: (1) the strong nonlinearities and complexities are mitigated when the SVC equipment are introduced to the multimachine excitation systems and the explosion of complexity problem of the backstepping method is overcome by combining the dynamic surface control method with neural networks (NNs) approximators; 2) the tracking error of the power angle can be kept in the prespecified performance curve by introducing the error transformed function; (3) instead of estimating the weighted vector itself, the norm of the weighted vector of the NNs are estimated, leading to the reduction of the computational burden. It is proved that all the signals in the multimachine excitation system with SVC are semiglobally uniformly ultimately bounded.     

静止无功发生器与晶闸管投切电容器协同运行混合无功补偿系统

提出一种低成本混合型无功补偿系统(hybrid var compensator,HVC),它由一台较小容量的静止无功发生器(static synchronous compensator,STATCOM)和较大容量的多组晶闸管投切电容器(thyristor switched capacitor,TSC)构成,其中STATCOM用以实现快速连续无功调节,TSC实现无功的大容量分级调节,二者协同工作使HVC系统兼具STATCOM快速连续无功补偿及TSC低成本大容量无功补偿的优势,实现低成本大容量的无功连续补偿。在分析HVC基本工作原理的基础上,提出基于专家决策的HVC协调控制方法,实现离散子系统TSC和连续子系统STATCOM的协调控制,确保HVC能进行快速大容量的无功补偿,针对传统的STATCOM串级电压控制器中调节器多、控制器参数难以设计的缺点,提出基于瞬时功率平衡的电压控制策略,以降低STATCOM控制复杂度,提高可靠性,使系统更易于实现。仿真及现场应用结果证明HVC能够实现无级连续无功补偿,并且成本低,在满足高电耗企业节能降耗需求的基础上,为应用单位减少了投资。     

高空电推进系统的积分滑模反演速度控制

针对高空电推进系统用永磁同步电机的转速跟踪控制问题,提出一种基于反演的积分滑模控制器.对控制器所采用的数学模型、控制算法、稳定性条件等进行研究.在反演法的基础上,将积分因子引入速度环,对转速误差进行补偿;采用指数趋近律构造电流误差的滑模面方程,以减小反演法对系统参数的敏感性;设计全局Lyapunov函数保证控制器的渐进收敛;基于SIMULINK和dSPACE实验平台完成反演和积分滑模反演控制系统的仿真和实验分析.仿真和实验结果表明,相比于反演控制,当参考转速由300 r/min上升到400 r/min时,积分滑模反演控制系统的转速动态响应时间由0.2s减小到0.1s;突加1N·m负载时,转速超调由8 r/min减小到2 r/min,在系统参数摄动条件下,电机稳态运行时无转速静态误差.     

Adaptive backstepping repetitive learning control design for nonlinear discrete‐time systems with periodic uncertainties

This paper addresses a tracking problem for uncertain nonlinear discrete‐time systems in which the uncertainties, including parametric uncertainty and external disturbance, are periodic with known periodicity. Repetitive learning control (RLC) is an effective tool to deal with periodic unknown components. By using the backstepping procedures, an adaptive RLC law with periodic parameter estimation is designed. The overparameterization problem is overcome by postponing the parameter estimation to the last backstepping step, which could not be easily solved in robust adaptive control. It is shown that the proposed adaptive RLC law without overparameterization can guarantee the perfect tracking and boundedness of the states of the whole closed‐loop systems in presence of periodic uncertainties. In addition, the effectiveness of the developed controller is demonstrated by an implementation example on a single‐link flexible‐joint robot. Copyright © 2014 John Wiley & Sons, Ltd.     

基于多汇集风电场SVC无功补偿的研究

随着风电场大量接入电网,常见的接入电网方式有两种:各个风电场直接接入电网、各个风电场汇集在风电场群汇集站再并入电网。由于多数风电场均位于电网末端,远离负荷中心,周围缺少火电和水电等其他电源的支撑和调节,可能会对地区电网线路传输功率及电压稳定性产生较大的影响。目前,常见的解决方法有3种:在风电场群汇集站处加装静止无功补偿器进行无功补偿、在各个风电场加装静止无功补偿器进行无功补偿、在各个风电场和风电场群汇集站均加装静止无功补偿器进行无功补偿。为了使无功补偿装置安装合理化以及无功补偿最优化,并基于这3种补偿方法,研究了在风电场接入容量不同以及地理距离不同的情况下,静止无功补偿器(SVC)的安装位置以及补偿容量的问题,并通过PSASP仿真程序验证了最优补偿的合理性,提高了系统电压的稳定性以及风电送出能力,为风电场建设提出借鉴和理论参考依据。     

An adaptive nonlinear output feedback controller using dynamic bounding with an aircraft control application

An adaptive output feedback control scheme is developed for a class of nonlinear systems with uncertain nonlinearities, which are bounded by both static and dynamic functions of the system output, and with actuator failures whose failure time instants, patterns and values are unknown, as motivated from an aircraft flight control application. An adaptive backstepping control law using dynamic bounding is constructed to deal with unknown actuator failures as well as system parameter and dynamics uncertainties to guarantee desired system performance. Complete stability and performance analysis and illustrative simulation results of an application to aircraft flight control are presented. Copyright © 2008 John Wiley & Sons, Ltd.     

一类刚性负载双轴伺服系统的非线性观测器控制设计策略

提出了一种基于非线性观测器的命令滤波自适应反步控制(OCFABC)方法,以解决具有LuGre摩擦模型的双轴伺服系统中的位置跟踪和速度同步问题。观测器用于系统摩擦补偿。命令滤波器作用于虚拟控制信号,解决反步法中的计算爆炸问题,建立误差补偿方程,提高跟踪精度。此外,还设计了速度同步信号,以达到更好的系统同步效果。利用Lyapunov理论分析了闭环系统的稳定性。最后,通过仿真和试验结果证明了所设计方法的有效性和优越性。     

A new adaptive backstepping control algorithm for motion control systems — an implicit and symbolic computation approach

A new adaptive integral backstepping control algorithm for motion control systems is proposed. The design approach is non‐conventional in that it only implicitly incorporates error states into a design Lyapunov function and computes time derivative of the Lyapunov function symbolically to the point of getting parameter estimate update laws on which desirable structures are imposed. The closed‐loop error system turns out to be linear and time‐varying and can be reformulated as a linear–non‐linear cascade system. Uniform exponential stability or absolute stability can be achieved. The design is robust against system parameter variations. The effectiveness and robustness of the control algorithm are verified by numerical examples. Copyright © 2002 John Wiley & Sons, Ltd.     

矿热炉混合无功补偿系统优化协调控制研究

为解决矿热炉给电网中其他用户带来的电能质量问题,尤其是电压跌落和电压闪变,提出了一种由FC、SVC和STATCOM组成的混合无功补偿系统。其中FC负责低层低成本无功补偿;SVC负责跟踪补偿无功功率变化,改善三相不平衡;STATCOM则通过快速响应来补偿SVC由于响应速度慢而导致的补偿误差,从而提高整个混合补偿系统的补偿精度。三者通过系统规则判断进行协调控制。对混合无功补偿系统进行仿真试验,分析对比了系统投入前后的电压波形,证明其补偿效果等效于等容量的STATCOM。     

电网电压稳定与无功功率补偿的研究

从电压稳定的基本概念和现有的研究成果出发,分析了电压稳定的机理和无功功率补偿的方法,明确现今电网无功问题的三个特点,说明系统的无功功率平衡与电压稳定和电压崩溃是密不可分的,并就无功补偿的不同方式,对防止电压崩溃的发生提出了相应的对策。分析了静止无功补偿器（SVC）与静止无功发生器（SVG）的工作特性与基本原理,对SVC与SVG进行了比较与述评,得出了应用SVG可以更好地控制无功功率的分布,提高电网的电压稳定水平,有效地避免电压崩溃的结论。     

Mapping filtered forwarding‐based robust adaptive control for uncertain nonlinear systems with input constraint

This work develops a robust adaptive control algorithm for uncertain nonlinear systems with parametric uncertainties and external disturbances satisfying an extended matching condition. This control method is implemented in the framework of a mapping filtered forwarding‐based technique. As an attractive alternative of the adaptive backstepping method, this bottom‐up strategy forms a virtual controller and a parameter updated law at each step of the design, where Lyapunov functions and the prior knowledge of system parameters are not required. The boundedness of all signals is guaranteed by using Barbalat's lemma. According to immersion relationship, a compliant behavior of systems behaves accordingly to the lower‐order target dynamics. Furthermore, input constraints are handled by estimating a saturated scaling. A spring, mass, and damper system is used to demonstrate the controller performances via simulation results.     

Online data‐driven composite adaptive backstepping control with exact differentiators

This paper presents an online data‐driven composite adaptive backstepping control for a class of parametric strict‐feedback nonlinear systems with mismatched uncertainties, where both tracking errors and prediction errors are utilized to update parametric estimates. Hybrid exact differentiators are applied to obtain the derivatives of virtual control inputs such that the complexity problem of integrator backstepping can be avoided. Closed‐loop tracking error equations are integrated in a moving‐time window to generate prediction errors such that online recorded data can be utilized to improve parameter adaptation. Semiglobal asymptotic stability of the closed‐loop system is rigorously established by the time‐scales separation and Lyapunov synthesis. The proposed composite adaptation can not only avoid the application of identification models and linear filters resulting in a simpler control structure, but also suppress parametric uncertainties and external perturbations via the time‐interval integral. Simulation results have demonstrated that the proposed approach possesses superior control performances under both noise‐free and noisy‐measurement environments. Copyright © 2015 John Wiley & Sons, Ltd.