基于变分模态分解的低电压电能扰动抑制系统设计

低电压造成的扰动问题会直接影响供电系统正常运行,为了保证居民的用电质量,基于变分模态分解设计了一种新的低电压电能扰动抑制系统。硬件部分由网侧电流互感器、状态反馈控制器、状态观测器、光伏并网逆变器四部分组成,通过网侧电流互感器监测电流数据,利用状态观测器得到电流数据,并传输给状态反馈控制器,由状态反馈控制器反馈给控制系统,光伏并网逆变器则起到保护电流稳定电压的作用。软件部分由低电压电能扰动因子提取程序与低电压电能扰动抑制程序组成,在得到电流数据后,由低电压电能扰动因子提取程序结合变分模态分解来对扰动因子进行提取,判定扰动因子,应用低电压电能扰动抑制程序对电能扰动进行抑制,解决低电压电能扰动问题。实验结果表明,电能扰动故障发生时刻设计系统抑制时间仅为0.05 s,故障清除时刻抑制时间仅为0.02 s,具有很好的抑制能力。     

基于偏差解耦的永磁同步电动机控制研究

在分析永磁同步电动机数学模型的基础上,推导出基于最大转矩电流比的矢量控制,但动态耦合关系依然存在,这造成了动态过程中电流分量互相影响,尤其在高速过渡过程中动态耦合影响更为显著,使电动机的动态性能变差。本文推导出一种偏差解耦控制,并与传统的反馈解耦控制进行了对比分析。仿真结果表明偏差解耦控制具有很好的电流控制特性。     

逆变器无差拍性能控制方案的分析与设计

分析了两种单电压环的无差拍控制方案。通过分析,比较了两者的异同,指出单纯保证输出电压无差拍控制方案的劣势。并详细分析了能够同时实现两个状态无差拍控制的单电压环控制方案。该方案利用输出电压反馈进行极点配置,实现系统对给定无差拍跟踪;利用负载电流进行前馈控制,实现系统对扰动的抑制。并针对控制策略进行了仿真,验证了方案的可行性。     

一种静不稳定无人机快速跃升与俯冲机动控制器设计

针对无人机在快速跃升与俯冲机动中存在的气动耦合、操纵耦合与不确定扰动,以及由于静不稳定性而造成的不稳定俯仰力矩等问题,提出了一种新的鲁棒模型参考自适应非线性逆控制器。首先,通过基于状态反馈的非线性逆控制完成多通道之间的解耦;然后,依据解耦后的线性闭环系统设计鲁棒模型参考自适应控制器,其主要作用是对非线性逆误差与不稳定俯仰力矩进行补偿,并对不确定扰动进行抑制,从而保证无人机在整个快速机动飞行中的稳定性。通过非线性仿真验证了该控制方法在快速跃升与俯冲纵向机动控制中的有效性与可靠性,并与典型的鲁棒伺服LQR最优控制器对比,说明了该控制器的解耦性能以及对于不确定扰动的抑制作用。     

三相电压型PWM变流器的线性化状态反馈解耦控制

三相电压型PWM变流器在实现能量变换的同时可以消除谐波、实现单位功率因数运行,是一个多输入多输出的非线性系统。文章建立了基于开关函数的变流器数学模型,采用非线性变换以及引入变流器交直流侧的动态功率平衡两种方案相结合,得到了线性化的变流器数学模型。在线性化数学模型的基础上,提出了电压型PWM变流器的线性化状态反馈解耦控制。仿真结果表明该控制策略能较好地实现三相电压型PWM变流器有功功率和无功功率的解耦控制,具有较好的动态特性,而且网侧电流谐波含量很低。     

基于直接反馈线性的永磁同化步电机直接转矩控制

文中应用一种基于直接反馈线性化（DFL）理论的非线性控制方法．通过对系统输出变量进行李微分,得到反馈线性化所需的坐标变换和非线性系统状态反馈．实现了永磁同步电机系统的输入输出线性化．并将原系统分解为两个线性子系统：转速线性子系统和励磁电流线性子系统,实现了系统的解耦。仿真结果表明：基于直接反馈线性化解耦的永磁同步电机直接转矩控制系统具有较好的速度跟踪性能并提高了系统对电流扰动的鲁棒性。     

一种新型UPS无互联线并联下垂特性控制

传统的UPS无互联线并联下垂特性控制是采用频率下垂和幅度下垂来调节输出电压。这种控制方法虽然是有效的，但是它容易导致系统正反馈。文中提出了一种基于神经网络解耦控制的下垂特性控制方案。这种新的控制方法能有效地克服传统下垂特性控制的局限性。由仿真结果得，该方案下逆变电源均分负载电流的效果好，而且系统动态响应性能高。     

基于ESO的三相PWM整流器电流滑模控制研究

为解决三相PWM整流器在电流滑模控制下的高性能与电流抖振之间的矛盾,提出了一种基于扩张状态观测器(ESO)的新型电流滑模控制方案.采用扩张状态观测器观测系统的总扰动,构建新的滑模控制趋近律,将扰动观测值补偿进滑模控制律中,采用空间矢量脉宽调制的方法产生开关信号,提高系统抗扰动能力的同时削弱电流抖振.仿真和实验结果表明,...     

基于自抗扰技术的三相电力电子负载电流控制

本文提出一种基于自抗扰技术的三相电力电子负载模拟变换器电流控制方法,解决了传统电流控制存在电流解耦困难、参数摄动、抗干扰能力差的问题。通过建立基于同步旋转d/q坐标系下负载模拟变换器的数学模型,分析电流耦合产生的机理以及影响系统的扰动。设计一阶自抗扰控制器,将系统分析得到的问题作为系统扰动并通过自抗扰控制器消除扰动,达到控制效果,并选定该控制器参数整定方法。通过仿真、实验结果表明,所提出的基于自抗扰技术的三相电力电子负载的电流控制方法可确保负载模拟变换器获得较好的稳态和动态性能,特别是针对电流耦合以及系统外部扰动和内部扰动都具有较好的控制效果。     

基于自适应逆控制的有源滤波器输出波形校正

传统的控制系统在设计过程中,需要在动态性能和扰动抑制之间进行一些折衷。自适应逆控制为基于前馈的开环控制,采用特别的反馈结构,可以消除对象的扰动而不改变对象的动态特性,使动态特性控制和对象扰动控制成为两个单独的过程,可以进行独立设计,这个特点也是自适应逆控制的最大优势。论文将自适应逆控制理论应用于有源滤波器（APF）中,用来控制电压源型逆变器输出电流波形的校正。仿真、实验结果验证了理论分析的有效性。     

State-feedback decoupling control of 5-DOF magnetic bearings based on α-order inverse system

In the face of magnetic bearing rotor system multivariable, nonlinear, strong coupling control problems, a novel control decoupling method based on inverse system state feedback decoupling theory for the five degree of freedom of active magnetic bearing is presented. It solved the problem of ignoring the limitation of control parameters in conventional control methods. In this paper, the rigid body dynamics model of magnetic suspension rotor is established and the linearization is carried out. In this study, a decoupling pseudo-linear system is constituted by cascading the α-order inverse system based on the state-feedback with the original system. Moreover, in order to improve the robustness of the whole system and reject the influence of the un-modeled dynamics, the internal model controller is designed to synthesize the whole system. Both simulations and experiments demonstrate the effectiveness in decoupling of magnetically-levitated rotor system, and the disturbance rejection of proposed control scheme can be enhanced compared with un-decoupled control schemes.     

Suppression of line voltage related distortion in current controlled grid connected inverters

The influence of selected control strategies on the level of low-order current harmonic distortion generated by an inverter connected to a distorted grid is investigated through a combination of theoretical and experimental studies. A detailed theoretical analysis, based on the concept of harmonic impedance, establishes the suitability of inductor current feedback versus output current feedback with respect to inverter power quality. Experimental results, obtained from a purpose-built 500-W, three-level, half-bridge inverter with an L-C-L output filter, verify the efficacy of inductor current as the feedback variable, yielding an output current total harmonic distortion (THD) some 29% lower than that achieved using output current feedback. A feed-forward grid voltage disturbance rejection scheme is proposed as a means to further reduce the level of low-order current harmonic distortion. Results obtained from an inverter with inductor current feedback and optimized feed-forward disturbance rejection show a THD of just 3% at full-load, representing an improvement of some 53% on the same inverter with output current feedback and no feed-forward compensation. Significant improvements in THD were also achieved across the entire load range. It is concluded that the use of inductor current feedback and feed-forward voltage disturbance rejection represent cost-effect mechanisms for achieving improved output current quality.     

Decoupling and pole-zero assignment of singular systems with dynamic state feedback

This paper refers to the problem of designing a linear state feedback dynamic controller for single-input, single-output decoupling of linear, time-invariant, singular systems. Sufficient conditions are established for the state-feedback decoupling problem to have a solution. In the case where the system satisfies these conditions, the class of controller matrices which decouple the system is given. Finally a method is presented for pole-zero placement in the decoupled singular system and a structure is described for the realization of the generalized transfer function matrices.     

Disturbance rejection control method for permanent magnet synchronous motor speed-regulation system

The speed-regulation problem for permanent magnet synchronous motor (PMSM) system is studied in this paper. To guarantee the disturbance rejection ability of the closed loop system, most of the existing advanced control methods develop disturbance rejection control laws only for speed loop. To further improve the disturbance rejection ability, a control scheme which employs disturbance rejection control laws for not only speed loop but also the q-axis current loop, is developed here. Considering the dynamics of q-axis current, the coupling between rotor speed and d-axis current as well as the back electromotive force are regarded as lumped disturbances for the q-axis current loop, which are estimated by introducing an extended state observer (ESO). Thus a composite control law consisting of proportional feedback and disturbance feedforward compensation is developed to control the q-axis current. Simulation and experiment comparisons are presented to verify the effectiveness of the proposed method.     

导引头隔离度对寄生回路稳定性的影响

为研究隔离度对制导控制系统稳定性的影响,提出了隔离度传递函数的概念,建立了隔离度传递函数模型和隔离度寄生回路模型。基于此模型,利用频域法分析了隔离度传递函数的特性,利用劳斯判据研究了制导参数对寄生回路稳定域的影响以及制导系统阶数对寄生回路失稳频率的影响。结合某红外图像导引头实例,对隔离度传递函数和寄生回路稳定性进行了深入分析,最后提出了提高隔离度寄生回路稳定性的措施。研究表明:隔离度寄生回路稳定性最严重的区域位于中频段,而提高导引头稳定回路在该段的增益可有效提高导引头隔离度水平,增加寄生回路的稳定性。     

基于自抗扰控制半潜平台动力定位控制器设计

本文采用自抗扰控制技术,设计了半潜式平台动力定位控制器.跟踪微分器实现给了平台定位置的快速稳定跟踪;非线性扩张观测器能进行平台运动位置、速度和系统扰动的估计,通过非线性反馈控制对系统总扰动进行补偿,实现了平台定位的精确控制.经仿真实验验证：该控制器具有响应快、精度高、稳定性好,抗干扰能力强、鲁棒性强等优点.     

全捷联对地攻击制导武器导引头隔离度对制导系统性能的影响

针对全捷联图像导引头隔离度问题,分别推导了由探测器和角速率陀螺之间的刻度尺系数误差及动力学偏差引起的隔离度传递函数;采用系数冻结法及劳斯判据分析了含有隔离度寄生回路的制导系统稳定区域,给出了不同无量纲末导时间下制导系统稳定时刻度尺误差和动力学偏差的取值范围;利用伴随函数法研究了隔离度对制导精度的影响。以上研究结果可以为全捷联制导武器制导控制系统参数设计提供参考,对于隔离度正反馈的情况应予以更多关注。     

采用自抗扰控制的空间激光通信精跟踪系统

空间激光通信的视轴稳定是激光通信链路建立的前提。针对通信终端载体的非线性扰动和扰动模型未知造成视轴稳态误差较大的问题,设计了自抗扰控制方法,并采用模糊控制理论自适应调整非线性状态误差反馈控制律中的相关参数。实验结果表明,与自适应PID控制方法相比,采用模糊自抗扰控制方法可以有效抑制平台的非线性扰动,并且具有较快的响应速度与较强的鲁棒性,可以满足系统的稳态精度要求。     

Integrated MIMO fault detection and disturbance observer-based control

This paper presents a new method of disturbance observer-based control (DOBC) for multi-input-multi-output (MIMO) highly-coupled unstable systems. In contrast to the current input–output approach for stable single-input-single-output (SISO) systems, the Youla parameterization of stabilizing controllers by full order state observer (FOSO) feedback control is shown more appropriate for general MIMO systems, while retaining the intuitive aspects of DOBC design. We propose a general MIMO DOBC expanded from this single FOSO stabilizing control, where a parallel number of FOSOs for fault detection, state estimation, and disturbance observer are integrated to achieve the relevant operational requirements and performance. Within this integrated control system, we propose a MIMO disturbance observer design method by a game-theoretic detection filter (GTDF) design. The DOBC design features GTDF disturbance decoupling followed by H-infinity model matching to establish the desired bandwidth for each channel of the decoupled disturbance observer. The proposed DOBC is applied to an open-loop unstable MIMO Active Magnetic Bearing Spindle (AMBS). Experimental results are presented to demonstrate the design method and control performance.