精馏模糊解耦控制系统探究

本文介绍了精馏塔的精馏工艺,分析了精馏塔塔顶和塔底温度控制回路的耦合关系,提出了模糊解耦控制应用的必要性。针对精馏塔塔顶和塔底温度的控制特点,设计了一种双输入双输出模糊解耦控制系统,具体分析了系统中该模糊解耦控制器的结构以及模糊控制各环节的具体实现方法,应用Simulink对控制系统进行仿真研究,得到了较好的控制效果。     

STATCOM非线性交叉解耦控制研究”

为了克服静止同步补偿器(STATCOM)进行动态补偿时有功电流和无功电流的非线性、强耦合问题,建立了d-q坐标下STATCOM的数学模型,提出了非线性交叉解耦控制方法,利用MATLAB/SIMULINK仿真软件对系统进行了仿真,通过实验结果验证了静止同步补偿器在解耦控制下,有良好的无功电流跟踪特性,能有效改善电网质量。     

对称迟后-超前校正的一体化设计方法

本文首先分析了一类迟后-超前校正环节的频率特性,严格证明了在半对数坐标系下,其幅频特性是轴对称的,其相频特性是中心对称的,进而将此类校正环节称为对称迟后-超前校正环节。在校正环节的参数满足一定条件下,本文指出：对称迟后-超前校正环节在超前环节作用的频段内,能提供正的相角和负的幅值。进一步,给出了该校正环节所能提供的近似最大相角和所对应频率,并给出了在该频率点该校正环节的近似幅值。基于这些结论,给出了利用对称迟后-超前环节进行校正的两种一体化设计方法。     

多变量系统辨识及其PID解耦控制的研究

现代工业过程中面临越来越多的结构复杂的多变量系统,传统的单变量PID控制方法已无法满足要求,为了解决多变量系统的控制问题,以两输入两输出系统为例,提出一种基于阶跃响应的多变量频域模型辨识方法,并将此种方法与对角矩阵解耦控制方法相结合应用于多变量PID控制系统中.最后对滞后环节近似部分和对角矩阵解耦方法进行仿真验证.结果表明该方法能够更好的控制系统变量,误差减小50%以上.     

空间光通信的粗精复合轴解耦技术研究

国内外的空间光通信系统都采用粗精复合轴结构实现大视场、高精度、高闭环带宽的跟踪系统.粗精控制环解耦问题是复合轴结构控制系统中很重要的问题,它会影响整个APT系统的性能.通过软件仿真和桌面实验,对双探测器的复合轴解耦问题进行了深入的研究,在桌面实验系统中实现了空间光通信要求的3urad的控制精度.     

三电平PWM整流器双闭环控制系统的研究

基于三电平PWM整流器的数学模型,建立dq旋转坐标系中的解耦状态方程。为了实现有功和无功的结构,运用前馈解耦方案。同时,双闭环控制系统能够实现输入侧近似单位功率因数及直流母线电压稳定。最后,为实现三电平PWM整流器双闭环控制系统,本文设计一套硬件实验装置并且可在DSP下编写控制软件。     

数字信号频谱编码传输中基于一阶保持的软同步方法

该文提出了一种应用于数字信号频谱编码传输中的完全利用软件来实现的同步方法,并对该方法进行了详细的理论描述,提出了实现同步的步骤和方法。并且与传统的载波同步相比较,阐述了这种用软件来实现同步的优点。     

基于神经网络的VAV空调系统多区域解耦控制

分析变风量空调系统多区域运行时的耦合关系,针对变风量空调参数多变、强耦合的特点,提出了一种改进的误差反向传播算法的神经网络分散解耦控制方法,对送风量-室内温度进行解耦;然后采用基于BP神经网络的PID控制方法对解耦后的2个近似独立的单输入单输出系统进行控制。仿真结果表明,神经网络分散解耦算法具有很强的自学习功能和自适应解耦能力,控制系统响应快,稳态误差小,有效提高变风量空调系统的控制精度及性能指标。     

单电机驱动椭偏双补偿器旋转结构及系统控制

针对目前双伺服电机控制补偿器旋转的椭偏测量技术中电机同步旋转控制复杂,且探测器同步信号触发采集困难、长时间运行稳定性差等缺点.提出一种基于单电机驱动的双相位补偿器旋转结构以及控制方法.该结构中与伺服电机连接的同步齿轮的直径比为5∶3,不同的齿轮直径是为实现对双旋转补偿器的差速控制,结合双旋转补偿器椭偏测量理论,实现样品的多维度信息获取;且基于控制理论设计伺服电机驱动电路和信号触发采集电路,完成相关硬件方面设计.最终实现系统在长时间运行过程中补偿器转速稳定可控,一次测量可得穆勒矩阵16个参数,为椭偏测量样品各维度信息提供理论依据及技术支撑.     

变速恒频双馈风力发电系统仿真研究

阐述变速恒频双馈风力发电系统工作原理,在分析双馈异步发电机的动态数学模型的基础上,介绍了一种基于定子磁链定向的矢量控制方法,实现对电机的有功功率和无功功率的解耦控制,进而实现最大风能追踪。在DFIG转子励磁电源的研究中,重点讨论基于电网电压定向矢量控制技术的网侧变换器的控制方法,以实现网侧变换器交流侧单位功率因数控制和直流环节电压控制。Matlab仿真结果证明了控制策略的正确性和有效性。     

基于自适应遗传算法的去耦电容器自动选择

针对在电源分配网络设计过程中,人工选择去耦电容器个数会导致反复设计的问题,提出了基于自适应遗传算法的去耦电容器自动选择的方法。该方法模拟达尔文生物进化论的自然选择过程,在满足目标阻抗的同时,选择出使用去耦电容器总个数最少的方案,以实现自动选择的目的。仿真结果与PCB全波仿真软件结果对比表明,该方法能够满足工程应用的要求,并已被某大型IT企业所采用。     

利用半导体pn结结电容构成的沟道式电容器

为满足对电子系统中元器件性能提升、面积减小、成本降低等需求,利用感应耦合等离子体刻蚀技术(ICP),对低阻p型硅采用刻蚀、扩散、磁控溅射Al电极等工艺,使之形成凹槽状三维结构,制造出一种特殊的具有高密度电容量的硅基电容器。其特点是结构简单,电容量大(电容密度可达2.2×10–9F/mm2),容值可调,与现有微电子工艺兼容,可用于200MHz至数GHz的退耦或其他场合。同时由于半导体pn结固有的特性,该电容器可取代传统的贴片电容广泛用于电子系统中的退耦、滤波、匹配、静电和电涌防护等场合。     

An Efficient Power-Delivery Method for the Design of the Power Distribution Networks for High-Speed Digital Systems

In this paper, a new power distribution network (PDN) design method from a power delivery viewpoint is proposed. Two new parameters, the power delivery delay and the $Delta V$ time constant, are introduced to characterize the effects of the lead inductors and decoupling capacitors on the timely power delivery respectively for a high-speed PDN. The decoupling time of a PDN is accurately estimated from the power delivery delay introduced by the inductance of the discontinuities, the charge delivery speed, and the charge supply capacity of the decoupling capacitors are accurately characterized by the $Delta V$ time constant. Based on the two parameters, a complete and systematic power-delivery method for the design of a PDN is developed. The proposed design method is verified by SPICE, full-wave simulations, and measurements. For completion, some specific design considerations are also discussed in detail.      

Using fuzzy controller for improvement of power decoupling performance in PV systems

ABSTRACT

In photovoltaic systems in order to ensure the stable operation of the module, ripple value of the input voltage should be mitigated to a small value; for this purpose, the power decoupling circuit can be used. In this work, considering the four-switch-based power decoupling circuit developed, the conventional Proportional-Integral (PI) controller has been replaced with well-known fuzzy controller, which enjoys a wide range of control gain variation, both linear and nonlinear rules' capability, robustness and more flexibility. The operating modes of the circuit are addressed and accordingly the space state model is derived. Then, the proposed controller has been replaced and the performance of the system will be analysed. The power decoupling circuit along with the proposed controller is implemented by MATLAB/Simulink software. The simulation results show the ability of the proposed fuzzy controller to improve the performance of the system in comparison to the conventional PI controller. A deeper comparison of two controllers confirms that the system would experience more accuracy, faster response and lower total harmonic distortion (THD) in presence of the proposed fuzzy controller.     

基于元数据和反射的面向方面软件演化方法

面向方面软件中的基础程序的结构信息发生变化后,会导致意外的连接点丢失问题.其原因在于连接点的定义紧紧地依赖于基础程序的结构,这种紧密的耦合严重阻碍了面向方面软件的演化.提出一种基于元数据和反射的面向方面软件演化方法.在连接点定义和基础程序之间加入概念层,以实现连接点定义和基础程序结构的解耦.概念层模型用于描述基础程序的...     

Decoupling internal model control for the robust engagement of clutches

Research on the robustness of clutch engagement control is attracting considerable interest because of its wide applications in advanced powertrains. Internal model control (IMC) is advantageous because it can handle model errors and external disturbances with light computational loads. However, during clutch engagement, two control inputs (engine output torque and clutch transmitted torque) and two system outputs (driving speed and the driven part of the clutch) are coupled; moreover, the two reference inputs are considerably different. A method for directly decoupling and stabilizing multi-input multi-output systems controlled by a two-degree-of-freedom (2DOF) IMC is proposed based on the construction of V-canonical matrices. The proposed method allows simple expressions for the control algorithm to be obtained without computing an inverse matrix that is used conventionally. Two filters, considering both the reference inputs and system characteristics, are independently designed considering the decoupling operation. The simulation results show that the proposed decoupling 2DOF IMC gains a considerably less tracking error and better robustness to model error and disturbance compared to classical 2DOF IMC and model predictive control. The performance is validated via dynamometer experiments.     

Tensor methods for MIMO decoupling and control design using frequency response functions

Decentralized control design is commonly applied to design controllers for multi-variable control applications. The success of decentralized control design methodologies hinges on the quality of decoupling of the system. The aim of this paper is to develop a decoupling procedure that applies to multi-variable systems and only requires a frequency response function of the system. The proposed method builds on recent tensor decomposition methods. The potential of the method is shown both in a simulation and using experimental data. When applied on noisy data and on real-life systems, which are not possible to be exactly decoupled, the proposed method typically performs better compared to eigen-decomposition based method.     

IDL: Evaluating software quality based on PageRank algorithm

In the traditional method, the software quality is measured by various metrics of the software, such as decoupling level (DL), which can be used to predict software defect. However, DL, which treats all the ?les equally, has not taken file importance into consideration. Therefore, a novel software quality metric, named as improved decoupling level (IDL), based on the importance of documents was proposed. First, the PageRank algorithm was used to calculate the importance of ?les to obtain the weights of the dependencies, and then defect prediction models was established by combining the software scale, dependencies, scores and software defects to assess the software quality. Compared to most existing module-based software quality evaluation methods, IDL has similar or even superior performance in the prediction of software quality. The results indicate that IDL measures the importance of each ?le in the software more accurately by combining the PageRank algorithm in DL, which indirectly re?ects the quality of software by predicting the bug information in software and improves the accuracy of prediction result of software bug information.