三相电压型PWM整流器分数阶PID直接功率控制

研究了一种基于分数阶PID控制器的三相电压型PWM整流器直接功率控制方案,在瞬时功率理论的基础上设计了功率内环、直流电压外环的控制结构.由于基于整数阶PI控制器的抗扰性能差且对系统参数变化较敏感,在直接功率控制方法的直流侧电压控制环节引入分数阶PID控制器进行直流侧电压控制,根据系统功率模型采用分数阶控制器频域设计方法设计了分数阶P1D控制器.仿真实验证明,分数阶PID控制方案优于PI控制方案,具有良好的动态性能和较强的鲁棒性,响应速度更快,控制结果更精确.     

基于分数阶滑模控制的高精度印刷机纠偏系统研究

目的 解决卷对卷印刷收卷不齐的问题，提高收卷精度。方法 对印刷机收卷纠偏原理进行分析，建立收卷纠偏系统数学模型，提出基于分数阶滑模控制的纠偏算法，分析其稳定性。在不同收卷线速度、不同跑偏干扰输入信号的条件下进行仿真。搭建收卷纠偏实验平台，对2种控制方法进行收卷纠偏控制实验。结果 仿真结果表明，分数阶滑模控制器比传统PID控制器具有较好的动态性能和稳态性能。实验结果表明，分数阶滑模控制算法比传统PID控制具有更高的纠偏精度。结论 分数阶滑模控制算法可以有效提高印刷机收卷纠偏精度，满足高精度印刷要求。     

Extended Chen: a new class of chaotic fractional-order systems

A new class of chaotic fractional-order systems is introduced and its necessary conditions for chaotic behaviour of this class have been provided. These chaotic systems are constructed based on the extension of fractional-order chaotic Chen system by addition of a general function term, satisfying some necessary conditions. This property makes the chaotic behaviour of the extended system, to large extent, independent of the selected function and so a vast range of chaotic systems can be synthesized. The main application of the proposed chaotic systems may be in secure communication systems. To make the subject clearer and in order for validation of the proposed model, five examples are provided and their results are simulated. The results confirm the theoretic analyses very well.     

New state-space approach and its application in thermoelasticity

In this work, a new state-space approach in the context of fractional-order theory of thermoelasticity is introduced. This new method utilizes the diagonalization of a square matrix by the use of its eigenvalues and vectors. This new approach is applied to a 1-D problem for a half-space subjected to a thermal shock. Laplace transform technique is used throughout. The inversion of the transforms is performed using a numerical inversion technique based on the Fourier series expansion technique. The effects of the time and the fractional parameter on variable field distributions are discussed and represented graphically.     

一类分数阶非线性时滞系统的稳定性与镇定（英）

稳定性是控制系统分析与设计的基础．探索分数阶系统,特别是分数阶时滞非线性系统的稳定性条件是控制理论与工程领域中的难点问题．本文研究了一类分数阶非线性时滞系统的稳定性和镇定．通过将原系统转化成等价的分数阶积分系统,再借助不等式放缩技术,提出了一个有效且形式简单的确保该类系统稳定新的时滞无关稳定性准则．根据所得的稳定条件,提出了基于时滞线性反馈控制器的镇定控制方法．最后,数值实例验证了所得结果的有效性．此外,本文所使用的方法可以推广和应用于其他类型的分数阶系统的稳定性和镇定控制．     

Intelligent Networks for Chaotic Fractional-Order Nonlinear Financial Model

The purpose of this paper is to present a numerical approach based on the artificial neural networks (ANNs) for solving a novel fractional chaotic financial model that represents the effect of memory and chaos in the presented system. The method is constructed with the combination of the ANNs along with the Levenberg-Marquardt backpropagation (LMB), named the ANNs-LMB. This technique is tested for solving the novel problem for three cases of the fractional-order values and the obtained results are compared with the reference solution. Fifteen numbers neurons have been used to solve the fractional-order chaotic financial model. The selection of the data to solve the fractional-order chaotic financial model are selected as 75% for training, 10% for testing, and 15% for certification. The results indicate that the presented approximate solutions fit exactly with the reference solution and the method is effective and precise. The obtained results are testified to reduce the mean square error (MSE) for solving the fractional model and verified through the various measures including correlation, MSE, regression histogram of the errors, and state transition (ST).     

基于FO-PI控制器的直流微网母线电压控制策略

为改善直流微电网母线电压稳定性及动态性能,提出一种基于自适应参数整定的FO-PI控制器控制直流母线电压方法。该方法在传统PI控制策略的基础上引入具有多参数可调的FO-PI控制器,并将带有自适应权重策略的粒子群算法运用于FO-PI控制器,从而解决控制器在具有多个参数时不可同时调节这些参数的问题。让直流微电网电压控制系统达到更优的可控性及灵活度。实验结果表明,所提出的控制策略在不增加系统成本的同时,能够使母线电压抗负载扰动能力更强,而且其整体性能优于传统控制方法。     

Partial fraction expansion–based realizations of fractional-order differentiators and integrators using active filters

Approximations of the fractional-order differentiator and integrator operators s^±r are proposed in this work. These approximations target the realization of these operators using standard active filter transfer functions. Hence, circuit implementations in integrated circuit form or in discrete component form are significantly facilitated. Complementary metal-oxide-semiconductor (CMOS) realizations of the proposed approximations are given and validated via simulations using the AMS 0.35 μm CMOS technology, while experimental results using operational amplifier circuits are tested and confirm the proposed theory.     

指标函数终端自由和受函数约束的分数阶系统的最优控制

将求解整数阶系统最优控制的方法和步骤拓展到分数阶系统的最优控制中,对由Caputo定义的分数阶微分方程描述的分数阶系统提出了求解性能指标函数在始端固定的条件下,终端时间固定而终端状态自由和始端固定、终端时间固定而终端状态受函数约束的最优控制的状态方程、伴随方程、控制方程、横截条件和终端约束方程,并给予了证明.     

分数阶超混沌系统的自适应函数投影同步

研究一类具有不确定性参数的分数阶超混沌系统的自适应函数投影同步问题。基于分数阶系统稳定性理论和自适应控制策略,设计自适应控制器和参数更新规则,实现了系统的自适应函数投影同步,并对系统进行稳定性分析,数值仿真结果验证了该控制器和参数更新规则的有效性和正确性。