基于系统浸入和流形不变自适应方法的静止无功补偿器非线性鲁棒自适应控制方法

本文提出一种将系统浸入和流形不变(I&I)自适应控制方法与L2-增益抑制鲁棒控制方法相结合的静止无功补偿器(SVC)的非线性鲁棒自适应控制方法.所提方法首先通过参数估计误差和鲁棒控制律的设计,使得所构造的表示参数估计误差函数的流形不变且吸引,从而使参数估计误差在这一流形上收敛于零.然后,通过所设计的可调参数对参数估计误差的收敛性能进行控制,以此来保证参数估计器对不确定参数的自适应估计能力.最后,采用自适应逆推算法推导鲁棒控制律,并通过使不确定外部扰动满足从输入到输出的耗散性来保证系统对不确定扰动的鲁棒性.仿真结果表明,利用所提方法设计的SVC控制器和参数替换律在参数估计、发电机功角动态响应方面优于传统自适应逆推算法,从而提高了输电系统的稳定水平.     

非最小相位区间系统鲁棒稳定补偿器

研究了非最小相位区间系统鲁棒稳定补偿器的设计问题，得到了一个补偿器存在的充分条件，并利用保形映射及Ｎｅｖａｎｌｉｎｎａ－Ｐｉｃｋ插值定理提出了一个可行的补偿器设计方法。     

具有鲁棒稳定性的伺服补偿器设计

本文发展一种鲁棒控制器设计方法,并将该法用于一个大型精馏塔的控制,利用该法设计的控制器,能使闭环系统满足稳定性,渐近调节和跟踪,以及某些瞬态性能指标,即使在结构性建模不确定的情况下,这些性能指标仍能满足。     

SISO区间系统鲁棒稳定补偿器设计

本文研究了ＳＩＳＯ最小相位区间系统鲁棒稳定补偿器设计问题，基于Ｋｈａｒｉｔｏｎｏｖ定理及其推广，我们提出了一种利用胡尔维茨矩阵进行设计的方法，从而克服了某些设计理论用于区间系统设计时的局限性及技术处理上的困难性。     

结构不确定广义系统的鲁棒动态补偿器

对给定的不确定模式，得出了为保证广义闭环系统Ｈ稳定（或Ｄ稳定）动态补偿器所能容许的不确定上界。     

用动态补偿器实现鲁棒对角优势

该文讨论了用动态补偿器实现鲁棒对角优势问题.给出了用动态补偿器实现鲁棒对角优势的条件和求取动态补偿器的具体算法.最后给出了一个具体算例.     

一种区间系统鲁棒稳定补偿器设计的映射方法

研究了一类区间系统的四条棱边同时稳定的问题 ,利用保形映射及Nevanlinna-Pick插值定理提出了一个可行的补偿器设计方法.     

包含SVC和非线性负荷的电力系统耗散实现与控制

采用Hamilton函数方法研究了包含静止无功补偿器(SVC)和非线性负荷的电力系统的反馈控制问题. 首先建立了系统的非线性微分代数方程模型, 通过预置状态反馈完成了耗散Hamilton实现. 然后利用该耗散实现结构,通过阻尼注入方式设计了基于能量的SVC非线性控制器. 本文所设计的控制器结构简单, 物理意义明确. 仿真结果表明该控制器能有效提高电力系统的暂态稳定性.     

非线性不确定系统的鲁棒镇定与HJI微分不等式

研究一类带模有界条件的非线性不确定系统的鲁棒镇定,定义了Ｌｙａｐｕｎｏｖ意义下的鲁棒镇定概念,得到了系统鲁棒镇定的充分必要条件。结果说明,在带模有界条件下,非线性不确定系统的鲁棒可镇定性与一个扩展的Ｈａｍｉｌｔｏｎ Ｊａｃｏｂｉ－Ｉｓａａｃｓ（ＨＪＩ）微分不等式是否存在正解完全等价。     

Decentralized robust control of multiple static var compensators via Hamiltonian function method

Using the energy-based Hamiltonian function method, this paper investigates the decentralized robust nonlinear control of multiple static var compensators (SVCs) in multimachine multiload power systems. First, the uncertain nonlinear differential algebraic equation model is constructed for the power system. Then, the dissipative Hamiltonian realization of the system is completed by means of variable transformation and prefeedback control. Finally, based on the obtained dissipative Hamiltonian realization, a decentralized robust nonlinear controller is put forward. The proposed controller can effectively utilize the internal structure and the energy balance property of the power system. Simulation results verify the effectiveness of the control scheme.     

Hybrid adaptive robust control of static var compensator in power systems

To improve the transient response of an electric power transmission system, a hybrid adaptive robust control method is proposed in this paper for the static var compensator by incorporating the immersion and invariance adaptive (I&I adaptive) and L₂‐gain control. In contrast to the standard I&I adaptive control algorithm, establishing a target system is not required in constructing the robust control law with the proposed method. Thus, the procedure of solving PDEs to satisfy the immersion condition can be avoided. In addition, both parametric and non‐parametric uncertainties, which commonly exist in electric power transmission systems, are considered. The parametric uncertainty induced by the damping coefficient of the system is estimated by the designed adaptive law, which is constructed by ensuring the estimation error converges to zero. The non‐parametric uncertainty is caused by external disturbances and approximation errors in modeling the uncertain structure. By assuming that the L₂‐gain of the system to the non‐parametric uncertainties satisfies a dissipation inequality, we found that the robustness of the controller can be guaranteed. It is proved that all the system states are globally bounded and converge to a new stable equilibrium. Simulation results are also presented to show the effectiveness of the proposed control method in improving the transient response of the system and the convergence speed of the system states. Copyright © 2013 John Wiley & Sons, Ltd.     

A brand new nonlinear robust control design of SSSC for transient stability and damping improvement of multi-machine power systems via pseudo-generalized Hamiltonian theory

Nonlinear robust control of static synchronous series compensator (SSSC) is investigated in multi-machine multi-load power systems by using the pseudo-generalized Hamiltonian method. First, the uncertain nonlinear differential algebraic equation model is constructed for the power system. Then, the dissipative pseudo-generalized Hamiltonian realization of the system is established by means of variable transformation and prefeedback control. Finally, based on the obtained dissipative pseudo-generalized Hamiltonian realization, a brand new nonlinear robust controller is put forward. The proposed controller can effectively use the internal structure and the energy balance property of the power system. Simulation results demonstrate the effectiveness and robustness of the control scheme.     

Coordinated nonlinear robust control of TCSC and excitation for multi-machine systems

An advanced nonlinear robust control scheme is proposed for multi-machine power systems equipped with thyristor-controlled series compensation (TCSC). First, a decentralized nonlinear robust control approach based on the feedback linearization and H∞ theory is introduced to eliminate the nonlinearities and interconnections of the studied system, and to attenuate the exogenous disturbances that enter the system. Then, a system model is built up, which has considered all the generators‘ and TCSC‘s dynamics, and the effects of uncertainties such as disturbances. Next, a decentralized nonlinear robust coordinated control law is developed based on this model. Simulation results on a six-machine power system show that the transient stability of the power system is obviously improved and the power transfer capacity of long distance transmission lines is enhanced regardless of fault locations and system operation points. In addition, the control law has engineering practicality since all the variables in the expression of he control strategy can be measured locally.     

Voltage control for static var compensator using novel optimal nonlinear PI

Static var compensators (SVCs) are used for voltage and reactive power control in power systems. In this paper, we will consider the structure of SVCs that mainly consists of Y -connection of mechanically-switched capacitor (MSC) and delta connection of thyrister-controlled reactor (TCR). First, the control model of SVC was established in this paper. Then, a novel optimal nonlinear voltage controller for SVCs is proposed. The proposed SVC voltage controller consists of a nonlinear function and a conventional PI controller. The improved simplex method (SPX) is presented to adjust and optimize the parameters of the nonlinear PI controller in real-time, and to make transient state response procedure of SVC optimum. The integration of time multiplied absolute error (ITAE) is adopted as the optimized objective function of SPX. Simulation and engineering application results show that the proposed voltage control method is able to track reference voltage value of SVC immediately. It also demonstrates that the whole SVC control system can synthetically compensate reactive power.     

Feedback control of nonlinear differential algebraic systems using Hamiltonian function method

Many complex dynamic systems, such as power systems, robotic systems, etc. can be modeled as the following nonlinear differential algebraic systems (NDAS) [1-4](1) where the vector 1 x1 ∈ X 1 ? Rn represents the state variable, and x2 ∈X2? Rn2 is the al…     

Nonlinear adaptive robust control design for static synchronous compensator based on improved dynamic surface method

In view of single machine to infinite bus system with static synchronous compensator, which is affected by internal and external disturbances, a nonlinear adaptive robust controller is constructed based on the improved dynamic surface control method(IDSC). Compared with the conventional DSC, the sliding mode control is introduced to the dynamic surface design procedure, and the parameter update laws are designed using the uncertainty equivalence criterions. The IDSC method not only reduces the complexity of the controller but also greatly improves the system robustness, speed and accuracy. The derived controller cannot only attenuate the influences of external disturbances against system output, but also has strong robustness to system parameters variance because the damping coefficient is considered in the internal parameter uncertainty. Simulation result reveals that the designed controller can effectively improve the dynamic performances of the power system.     

Digital self-triggered robust control of nonlinear systems

In this paper, we develop novel results on self-triggered control of nonlinear systems, subject to perturbations, and sensing/computation/actuation delays. First, considering an unperturbed nonlinear system with bounded delays, we provide conditions that guarantee the existence of a self-triggered control strategy stabilizing the closed-loop system. Then, considering parameter uncertainties, disturbances and bounded delays, we provide conditions guaranteeing the existence of a self-triggered strategy that keeps the state arbitrarily close to the equilibrium point. In both cases, we provide a methodology for the computation of the next execution time. We show on an example the relevant benefits obtained with this approach in terms of energy consumption with respect to control algorithms based on a constant sampling with a sensible reduction of the average sampling time.     

静止无功补偿器的自适应逆推无源反馈控制设计

通过将耗散系统理论和自适应逆推(adaptive backstepping)非线性控制算法相结合, 克服了无源反馈方法只能为输入输出相对阶为1的系统设计控制律的限制, 为带有静止无功补偿器的单机无穷大电力系统设计了鲁棒自适应控制器. 设计中兼顾了系统遭受不确定扰动以及阻尼系数难以精确测量情况下控制器的鲁棒性和自适应能力. 理论分析证明所提算法可保证系统内所有状态变量一致有界且渐近稳定, 系统误差全局渐近稳定. 仿真结果也表明, 所提算法使系统母线电压, 发电机功角以及转子角速度的暂态响应性能优于传统逆推算法, 系统误差迅速收敛至零, 与理论证明结果一致.