基于非线性扰动观测器的三相PWM整流器滑模控制

针对交流微电网中三相PWM整流器的运行状态易受负载扰动、滤波电容参数摄动影响的问题,本文提出一种基于非线性扰动观测器的三相PWM整流器滑模控制方法。首先,将负载扰动、滤波电容参数摄动等视为集总扰动,构建电压环非线性模型。其次,设计非线性扰动观测器,实现集总扰动的在线估计。为实现主动抗干扰控制和滑模抖振抑制,将估计的集总扰动引入到滑模面中,得到了一种含有扰动估计的新型滑模面。最后,基于滑模控制理论设计电压外环滑模控制器,并采用Lyapunov稳定性理论对其进行了稳定性证明。动态性能测试结果表明,非线性扰动观测器能够快速、准确地对集总扰动进行估计;与双环PI控制相比,所提控制的过渡过程时间减少了60%,电压跌落量减少了54%;滤波电容参数变化时,所提控制的动态性能保持良好。稳态性能测试结果表明,与传统滑模控制和双环PI控制相比,所提控制的电流总谐波畸变率分别减少了70%和44%,同时滑模抖振得到了有效地抑制。测试结果证明了所提控制方法的强抗负载扰动能力和良好的滤波电容参数鲁棒性。

扰动康托集子集的Hausdorff维数

讨论了一类与ω相关的扰动康托集E(ω)的子集BP(ω)在相容与不相容两种情况下其Hausdorff维数的相关性质,并得出了子集BP(ω)的Hausdorff维数的具体值。

T_D型扰动值模糊正规子群

将幂等扰动范数TD引入到扰动值空间上,以此为基础定义了TD型扰动值模糊正规子群,并研究了其性质与结构特征,从而拓广了扰动模糊集的代数结构理论。

运筹学中线性规划的鲁棒性

鲁棒线性规划(RLO)是建模方法,结合计算工具,解决当数据不确定和仅仅了解不确定集时的优化问题.本文讨论了线性优化问题所对应的鲁棒线性优化问题的理论与方法.

用DCS实现9^#碳化塔的非常规控制——浅谈两个数学模型在碳化控制过程中的应用

针对优化控制和模糊控制作为自控理论的两大前沿科学,在生产中的应用越来越广泛的状况,本文仅就优化控制在碳化过程中应用的可行性进行探讨。

正规互质因子扰动模型集的闭环辨识与检验

鲁棒控制的系统辨识问题是控制领域一个十分活跃的研究方向。该文综述了具有正规互质因子扰动模型集的辨识与检验的结果。在闭环实验数据已知时 ,给出了正规互质因子频域响应极大似然估计的解析表达式 ,介绍了这一估计的统计特性和最优参数选择。讨论了基于受约束曲线拟合的正规互质因子参数辨识问题 ,给出了其解析解。最后介绍了模型集与控制器和闭环实验数据相匹配的一个充分必要条件。这一条件可表示为一个线性约束和一个复数向量的欧几里德范数。根据这一条件 ,讨论了随机框架下的模型集检验问题 。

LC滤波型逆变器并网电压鲁棒预测控制

近年来,模型预测控制被广泛应用于两电平电压源逆变器以实现并网控制。然而,常规有限控制集模型预测控制(FCS-MPC)存在参数失配时预测精度下降的问题。为此,提出一种适用于LC滤波型逆变器并网电压鲁棒预测控制的无参数FCS-MPC方法。首先分析了参数变化对常规LC滤波型逆变器并网电压预测控制的影响。然后基于超局部建模理论建立了LC滤波型并网逆变器的二阶超局部模型,并研究了2个集总扰动的计算方法。该计算方法省去了网侧电流传感器,节约了成本,并实现了无参数预测控制。实验结果表明,与常规FCS-MPC方法相比,在参数不匹配的情况下,所提无参数FCS-MPC方法仍能达到较好的模型预测控制性能,验证了所提方法的有效性。

基于动态参考规划的鲁棒Tube模型预测跟踪控制

为实现扰动和约束作用下对系统的最优鲁棒跟踪,提出一种动态参考规划(DRP)方法,设计鲁棒Tube模型预测控制器(RTMPC)将系统状态驱动到以最优跟踪点为中心的扰动不变集内.基于DRP的RTMPC控制方法,以多步参考为决策变量,确保在线优化递归可行性的同时,增加在线优化的自由度;另外,通过设定目标函数惩罚标称状态轨迹和参考稳态之间、以及最后一步参考稳态和设定点之间的加权欧式距离,可实现最优鲁棒跟踪.

非线性规划的KKT点的强Lipschitz稳定性

本文讨论的是经典的扰动非线性规划问题的扰动KKT点集XKKT。我们的主要目的是研究XKKT在初始化问题的KKT点(0,x0)出的强Lipschitz稳定性。

THE ENERGETIC AGGREGATION AND RESLEASE IN THE HEAVY RAIN REGION

Using the new formula of moist available energy (MAE), the value of the MAE’s key terms ofthree heavy rainfall cases in Guangdong province in 1998 was calculated. The energetic aggregation andenergetic discharge are analyzed. It shows that the value of the key terms in the formula appears different featureclearly in the different precipitation period, as well as the function of each term presents in the heavy rain region.

基于事件触发和状态翻转的布尔控制网络输出跟踪

利用矩阵半张量积研究事件触发和翻转控制共同作用下布尔控制网络的输出跟踪问题.首先,基于布尔控制网络代数状态空间表示,构造增广系统将输出跟踪问题转化为状态集镇定问题;其次,得到布尔控制网络在两种控制下输出跟踪问题有解的充要条件,并在满足该条件时提出一种基于最小翻转节点集时间最优控制设计方法,进一步给出有限时间内寻找翻转节点集的计算过程;最后,给出一个算例说明结果的可行性.

Zeros of Perturbed m-Accretive Operators

In this paper, we give a full answer to a question posed by Kartsatos [1], and weaken the conditions of Kartsatos' theorem，

A SVD-based ensemble projection algorithm for calculating the conditional nonlinear optimal perturbation

Conditional nonlinear optimal perturbation(CNOP) is an extension of the linear singular vector technique in the nonlinear regime.It represents the initial perturbation that is subjected to a given physical constraint,and results in the largest nonlinear evolution at the prediction time.CNOP-type errors play an important role in the predictability of weather and climate.Generally,when calculating CNOP in a complicated numerical model,we need the gradient of the objective function with respect to the initial perturbations to provide the descent direction for searching the phase space.The adjoint technique is widely used to calculate the gradient of the objective function.However,it is difficult and cumbersome to construct the adjoint model of a complicated numerical model,which imposes a limitation on the application of CNOP.Based on previous research,this study proposes a new ensemble projection algorithm based on singular vector decomposition(SVD).The new algorithm avoids the localization procedure of previous ensemble projection algorithms,and overcomes the uncertainty caused by choosing the localization radius empirically.The new algorithm is applied to calculate the CNOP in an intermediate forecasting model.The results show that the CNOP obtained by the new ensemble-based algorithm can effectively approximate that calculated by the adjoint algorithm,and retains the general spatial characteristics of the latter.Hence,the new SVD-based ensemble projection algorithm proposed in this study is an effective method of approximating the CNOP.

On the properties of some sets of von Neumann algebras under perturbation

Let L be a type II1 factor with separable predual and r be a normal faithful tracial state of c~. We first show that the set of subfactors of L with property F, the set of type II1 subfactors of L with similarity property and the set of all McDuff sub/actors of t are open and closed in the Hausdorff metric d2 induced by the trace norm; then we show that the set of all hyperfinite von Neumann subalgebras of L is closed in d2. We also consider the connection of perturbation of operator algebras under d2 with the fundamental group and the generator problem of type II1 factors. When M is a finite yon Neumann algebra with a normal faithful trace, the set of all von Neumann subalgebras B of M such that B ∪→ M is rigid is closed in the Hausdorff metric d2.

General Admissibility for Linear Estimators of Multivariate Random Regression Coefficients and Parameters with Respect to a Restricted Parameter Set

This paper considers the linear model effected by random disturbance,Y=XB+ε,where [~B_ε]～([^(AΘ)_0],VΣ),and ΘTATX TN XAΘΣ.It gives a definition for general admissible estimator of a linear function SΘ + GB of random regression coefficients and parameters.The necessary and sufficient conditions for LY and LY + C to be general admissible estimators of SΘ + GB in the class of both homogenous and non-homogenous linear estimators are obtained.The conclusion is not dependent of whether or not SΘ + GB is estimable.