电压源逆变器混合多矢量预测共模电压抑制方法

近年来,为了减小共模电压对电压源逆变器的影响,模型预测共模电压抑制方法得到广泛研究。然而,常规的电压源逆变器模型预测共模电压抑制方法每个控制周期仅采用一个非零电压矢量作用,导致其电流谐波较大。为此,提出了一种混合多矢量模型预测共模电压抑制方法。首先给出了所提多矢量模型预测共模电压抑制方法的实现原理。其次详细分析了死区和电流纹波对共模电压的影响,并进一步对所提多矢量法进行改进。改进的方法在电流扇区7内使用单个非零电压矢量作用,而在其他扇区内使用多个非零电压矢量作用,从而不仅可以完全将共模电压限制在±Vdc/6之内,而且可以减小电流的总谐波畸变率。仿真和实验结果验证了该方法的有效性。     

机床用永磁同步电机预测电流控制方法研究

近年来,随着数字信号处理器和先进控制理论的发展,模型预测控制得到越来越多的关注和应用。针对数控机床用永磁同步电机常规单矢量模型预测直接电流控制方法存在电流谐波较大的问题,基于两电平电压源逆变器的基本电压矢量构造了6个虚拟电压矢量,并基于所构造的虚拟矢量建立了扩展电压矢量集。然后,设计了一种基于扩展电压矢量集的永磁同步电机预测电流控制方法。与常规的单矢量法相比,所提方法可明显降低电流的谐波,改善永磁同步电机的稳态控制性能。仿真和实验结果均验证了该方法的有效性,能够为同步电机在数控机床或相近的应用场合提供较好的理论支撑。     

NPC型三电平逆变器供电的永磁同步电机矢量控制系统

在分析永磁同步电机矢量控制理论的基础上,结合三电平中点钳位(NPC)逆变器输出谐波含量低、控制性能好等优点,提出了一种基于NPC型三电平逆变器的永磁同步电机(PMSM)矢量控制方法。深入分析了三电平逆变器空间电压矢量脉宽调制(SVPWM)技术,并利用Matlab/Simulink进行了基于三电平逆变器SVPWM算法的PMSM矢量控制仿真实验,结果表明三电平逆变器SVPWM和PMSM矢量控制的有机结合,有效地抑制了转矩脉动,提高了驱动性能。     

无轴承永磁同步电机转子速度自检测复合方法研究

针对单一转速估计方法难以实现全速范围内准确估计转子速度的缺陷,提出一种转速估计复合方法,即在零速及低速运行时,采用脉振高频信号注入法。该方法不依赖于电机模型参数而仅依赖于电机本身的凸极特性,可实现零速及低速时转子速度的准确估计;高速运行时,采用带多重次优渐消因子扩展卡尔曼滤波器（SMFEKF）进行转速估计,利用SMFEKF极强的模型失配鲁棒性和独特的强跟踪能力,有效地提高系统在稳态及突变状态下的跟踪性能。通过设计两种方法的“软切换”,实现低速到高速的平滑切换,并将该复合方法在无轴承永磁同步电机无速度传感器矢量控制系统中进行仿真研究。仿真结果表明：该复合方法能在全速范围内实现转子速度与位置的准确估计;在系统状态突变或负载扰动时,误差更小,鲁棒性更强。     

面向结构形状控制的驱动器结构参数与控制电压协同优化设计

飞机翼面结构形状的控制设计是提高飞机性能的关键技术。本文以压电纤维复合薄膜（Microfiber Composite,MFC）为驱动器,研究了协同优化设计MFC驱动器结构参数与控制电压以使飞机翼面结构具有理想形状的方法。以MFC的电极宽度、电极指间距、MFC厚度、压电陶瓷体积分数等驱动器结构参数以及控制电压为设计变量,以控制偏差最小为优化目标,以驱动器的击穿电压为约束,建立了驱动器结构参数与控制电压协同优化设计的模型;通过分析MFC驱动器结构参数对驱动性能的影响,给出了最优的驱动器结构参数;针对类似机翼翼面形状的平板扭转型面,给出了驱动器结构参数与控制电压协同的最优控制设计。设计结果表明：对于扭转变形,多个不同控制电压控制的型面均方差是相同控制电压控制均方差的45%,分析结果验证了本文所建立的协同优化设计方法的有效性。     

三电平逆变器SVPWM调速控制系统的研究

为了研究三电平逆变器在高压大容量电机变频调速中的应用，详细分析了三电平逆变器的开关模型和拓扑结构，得到了在三电平逆变器供电下异步电机调速系统的数学模型，提出了一种以空间矢量脉宽调制实现对逆变桥控制的方法。仿真表明，该方法可以有效地实现三电平空间矢量控制，实现高性能异步电机调速控制。     

一种新型自动化仪表用高斯基函数网络算法研究

本文提出一种新型基于高斯基函数网络的内模控制自动化仪表用算法,深入分析了高斯基函数网络内部模型和内模控制器的建立,主要结果考虑了形状参数和可变中心向量的自适应选取,仿真及温度实时控制结果表明该算法有效,具有很好的自适应性和鲁棒性,且易于实现并嵌入自动化仪表中,可应用于具有纯滞后,非线性和时变特性的被控过程。     

An improved approach for robust control of dynamic voltage restorer and power quality enhancement using grasshopper optimization algorithm

This paper presents a novel contribution of a low complexity control scheme for voltage control of a dynamic voltage restorer (DVR). The scheme proposed utilizes an error-driven proportional–integral–derivative (PID) controller to guarantee better power quality performance in terms of voltage enhancement and stabilization of the buses, energy efficient utilization, and harmonic distortion reduction in a distribution network. This method maintains the load voltage close to or equal to the nominal value in terms of various voltage disturbances such as balanced and unbalanced sag/swell, voltage imbalance, notching, different fault conditions as well as power system harmonic distortion. A grasshopper optimization algorithm (GOA) is used to tune the gain values of the PID controller. In order to validate the effectiveness of the proposed DVR controller, first, a fractional order PID controller was presented and compared with the proposed one. Further, a comparative performance evaluation of four optimization techniques, namely Cuckoo search (CSA), GOA, Flower pollination (FBA), and Grey wolf optimizer (GWO), is presented to compare between the PID and FOPID performance in terms of fault conditions in order to achieve a global minimum error and fast dynamic response of the proposed controller. Second, a comparative analysis of simulation results obtained using the proposed controller and those obtained using an active disturbance rejection controller (ADRC) is presented, and it was found that the performance of the optimal PID is better than the performance of the conventional ADRC. Finally, the effectiveness of the presented DVR with the controller proposed has been assessed by time-domain simulations in the MATLAB/Simulink platform.     

Predictive control strategies for wind turbine system based on permanent magnet synchronous generator

In this paper, Model Predictive Control and Dead-beat predictive control strategies are proposed for the control of a PMSG based wind energy system. The proposed MPC considers the model of the converter-based system to forecast the possible future behavior of the controlled variables. It allows selecting the voltage vector to be applied that leads to a minimum error by minimizing a predefined cost function. The main features of the MPC are low current THD and robustness against parameters variations. The Dead-beat predictive control is based on the system model to compute the optimum voltage vector that ensures zero-steady state error. The optimum voltage vector is then applied through Space Vector Modulation (SVM) technique. The main advantages of the Dead-beat predictive control are low current THD and constant switching frequency. The proposed control techniques are presented and detailed for the control of back-to-back converter in a wind turbine system based on PMSG. Simulation results (under Matlab-Simulink software environment tool) and experimental results (under developed prototyping platform) are presented in order to show the performances of the considered control strategies.     

一种新的移动机器人跟踪控制方法

以前轮转向、后轮驱动的四轮移动机器人为研究对象 ,建立了它的运动学模型 ,提出了一种鲁棒性好 ,实时性强 ,易于实现的跟踪控制方法。此方法将被跟踪路径划分成若干微小线段 ,应用以微小直线段代替曲线的方法 ,来进行分段跟踪。理论分析表明 ,该方法能保证系统的稳定性。采用此方法 ,计算简单 ,实现容易 ,并使得移动机器人跟踪的实时性、精确性得到提高。通过多种参考路径跟踪的仿真计算和实时跟踪控制试验 ,其结果均说明此方法是正确和有效的。     

面向结构形状控制的压电纤维复合薄膜驱动器布局方式与控制参数协同优化设计

能够根据工作环境改变翼面形状的自适应变形能力是未来航空、航天飞行器结构设计追求的重要目标。研究驱动器布局方式以及控制参数的设计技术是实现该目标的关键。以压电纤维复合薄膜(Macro fiber composites,MFC)作为驱动器,研究在一定数量的MFC驱动器条件下,通过驱动器布局与控制参数的协同设计,以实现类翼面平板结构具有理想形状的最优控制设计方法。以驱动器的铺设位置、铺设角度、层数、对称性以及控制电压为设计变量,以驱动器的击穿电压、铺设位置限制等为约束,建立多参数下的协同优化设计模型。数值算例以类机翼平板的弯曲、扭转、弯扭型面作为理想型面,以实际型面与理想型面在81个参考点位置的均方差为评价指标,设计获得弯曲、扭转和弯扭组合型面的均方差分别为9.977×10–5、4.394×10–4和5.308×10–4,实现了较高的变形控制精度。研究了驱动器数量对变形精度的影响,制作了具有6个驱动器的类翼面平板结构测试平台,仿真与试验结果高度吻合,从而验证了所提出的驱动器布局与控制电压协同优化设计模型的有效性和可行性。     

Multi-loop control of UPS inverter with a plug-in odd-harmonic repetitive controller

This paper proposes an improved multi-loop control scheme for the single-phase uninterruptible power supply (UPS) inverter by using a plug-in odd-harmonic repetitive controller to regulate the output voltage. In the suggested control method, the output voltage and the filter capacitor current are used as the outer and inner loop feedback signals, respectively and the instantaneous value of the reference voltage feedforwarded to the output of the controller. Instead of conventional linear (proportional-integral/-resonant) and conventional repetitive controllers, a plug-in odd-harmonic repetitive controller is employed in the outer loop to regulate the output voltage, which occupies less memory space and offers faster tracking performance compared to the conventional one. Also, a simple proportional controller is used in the inner loop for active damping of possible resonances and improving the transient performance. The feedforward of the converter reference voltage enhances the robust performance of the system and simplifies the system modelling and the controller design. A step-by-step design procedure is presented for the proposed controller, which guarantees stability of the system under worst-case scenarios. Simulation and experimental results validate the excellent steady-state and transient performance of the proposed control scheme and provide the exact comparison of the proposed method with the conventional multi-loop control method.     

基于矢量场法的无人机三维路径跟踪控制

为实现固定翼无人机自主跟踪预定的三维路径,提出了一种基于矢量场法的三维路径跟踪算法.建立了固定翼无人机的运动学模型,并介绍了用于三维路径跟踪的矢量场法,分别推导得出了直线路径和螺旋线路径跟踪所需的期望速度矢量,得到跟随路径所需的期望航向角和航迹角,为无人机横向通道控制和纵向通道控制提供输入,将无人机引导到预定的轨迹上.此外,针对航段切换问题,提出了一种基于圆角几何的切换策略,采用螺旋线来拟合相邻航段,根据无人机是否通过半平面作为切换准则,实现无人机平滑过渡相邻航段.通过仿真实验评估该算法在不同初始条件下的性能,结果表明该方法能使无人机跟踪预定的三维路径,且具有良好的跟踪性能.     

Design of adaptive backstepping congestion controller for TCP networks with UDP flows based on minimax

The congestion control problem of TCP network systems with user datagram protocol (UDP) flows is investigated in this paper. A nonlinear TCP network model with strict-feedback structure is first established. The unknown UDP flow is regarded as the external disturbance, and the maximum UDP flow is calculated by using the minimax approach. And then, a congestion control algorithm is proposed by using the adaptive backstepping approach. Meanwhile, the adaptive law is employed to estimate the unknown link capacity. The design of the adaptive law is to introduce a parameter mapping mechanism to limit the parameter identification range to a specified interval, thereby improving the estimation efficiency of the parameters. Furthermore, a state-feedback congestion controller is presented to make sure that the output of the system tracks the desired queue. The simulation results show the superiority and feasibility of the proposed method.     

三相电压型整流器SVPWM控制简化算法研究

提出了应用于三相电压型脉宽调制整流器的空间矢量简化算法。该算法采用输入电压空间矢量定向,合成所需参考电压,结合直接电流控制的方法进行电流跟踪控制,提高了整流器的整体性能,实现了单位功率因数整流。     

基于矢量分析的数控加工轨迹设计方法研究

描述了基于矢量分析和NURBS的数控加工轨迹设计方法。基于给定的被加工曲面在其参数域上的优化走刀方向集合,并依据标量场与梯度场的转化关系,建立了精确逼近离散方向矢量的走刀矢量场拟合模型,由此给出了数控加工轨迹的矢量表达形式。以NURBS作为发生矢量场的流函数并借助其较强的局部调控能力,通过调整控制点列,可望实现数控加工轨迹拓扑形状的整体优化调控。验证实例表明该方法能够进行复杂形状数控加工轨迹的精细设计,有利于保证精度指标下曲面加工效率的最大化。     

DTC和SFOC相结合的交流调速方法的研究

本文提出了一种将直接转矩控制（DTG）与定子磁场定向控制（SFOC）相结合的电压调节方式,一方面采用定子磁场定向控制,将交流量转化成直流流量以便于调节,另一方面又采用直接转矩控制技术调节转矩和磁通的偏差以加快响应,同时使用电压调节法避免了电流的解耦,而转矩和磁通的连续调节方式则克服了传统的直接转矩控制带来的转矩脉动。并通过仿真证明了该调速系统的性能。     

即时学习型迭代学习控制在励磁控制中的应用

将即时学习算法型迭代学习控制引入发电机的励磁控制。运用即时学习算法来解决系统的迭代学习控制初值问题,有效地估计初始控制量,加快了算法的收敛速度。仿真结果表明,所设计的励磁控制器与常规PID控制器和非即时学习型励磁控制器相比其收敛速度明显加快,具有更强的维持机端电压的能力。     

Control of a permanent magnet synchronous motor with a fuzzy sliding-mode controller

This paper is concerned with the topics in the speed control of a permanent magnet synchronous motor (PMSM). First, the vector control scheme in the synchronously rotating reference frame is used to formulate the PMSM model as the system plant. Then, the modern control theory using a sliding mode with fuzzy controller is presented to design the corresponding closed-loop system and Matlab/Simulink software is used for computer simulation. The original PMSM is stable, sluggish with large overshoot deficiency. It can be shown that the proposed fuzzy sliding-mode controller not only can delete the overshoot problem and achieve very good tracking performance without zero steady-state errors, but can also obtain good robustness to system parameter uncertainty. This proposed fuzzy-sliding mode controller for PMSM can be applied to the positioning control of the robot arms to suppress unnecessary vibrations. For assembly lines, this proposed controller can be used to obtain fast tracking ability, less steady-state errors, and robustness for different velocity movements.     

电动车用交流异步电机宽速域控制策略

针对异步电机转速控制中传统电压型磁链观测方法引起的直流偏移问题,设计了通过截止频率实时调整的饱和反馈低通滤波磁链观测器。为解决传统弱磁计算不准确问题,提出了一种恒压弱磁控制方法,有效地实现了恒转矩区和弱磁区的平稳调速。在建立基于转子磁场定向的交流异步电机矢量控制数学模型的基础上,制定了一种综合考虑恒转矩区和弱磁区的基于MRAS系统的转速控制策略。对所提出的控制策略进行了仿真与实验,结果表明系统获得了良好的控制效果,验证了算法的合理性和有效性。