他励直流电动机精确线性化自适应控制

基于他励直流电动机数学模型,研究了输出函数对于非线性控制器设计的影响。通过选择不同输出函数,应用精确线性化理论和极点配置方法,设计了转速状态反馈线性化控制器和输入输出反馈线性化控制器。理论推导发现,输入输出线性化控制器是全局稳定的,而状态反馈线性化控制器由于存在奇点,而不是全局能控的。将两种控制器的控制效果进行仿真对比,结果表明,输入输出反馈线性化控制器与状态反馈线性化控制器相比,控制器结构简单、动态性能好、运行稳定。在输入输出反馈线性化控制器的基础上,设计了输入输出反馈线性化控制器的自适应控制器。仿真结果表明,自适应控制器的抗系统参数变化干扰能力相比于输入输出反馈线性化控制器有明显提高。     

输入输出反馈精确线性化他励直流电动机转速控制

基于精确线性化理论,设计了他励直流电动机非线性转速控制器。从他励直流电动机数学模型出发,对系统的两个平衡点进行了研究。在此基础上,运用输入输出线性化方法,通过选择不同的输出函数,设计了两种非线性转速控制器,并研究了控制器内动态的稳定性。仿真结果表明,直接选择电机转速为输出函数设计的控制器,无法将系统控制到期望平衡点,选择转速和电枢电流线性组合为输出函数设计的非线性控制器,可以使系统稳定到期望的平衡点,实现电动机转速精确控制,且具有很好的控制精度、动态性能和抗干扰能力     

直流微电网内DC/DC变换器非线性控制策略研究

针对直流微电网内储能DC/DC变换器的非线性特性和输出电压扰动较大等问题。基于精确反馈线性化理论提出一种新颖的非线性级联控制器。在所提出的控制策略中,外部电压采用鲁棒性强的PI控制器,内部电流环采用非线性控制。在此基础上,对所提出的级联控制器策略进行Matlab/Simulink仿真,实验结果表明,所提方法具有良好的动态响应和鲁棒特性,在负载出现波动的情况下输出母线电压仍能保持恒定运行,并极大地提高了直流微电网内储能变换器的抗干扰能力。     

基于微分几何的永磁直线同步电机非线性控制方法研究

为了实现永磁直线同步电机在垂直升降系统运行过程中的良好控制性能,从电机学原理出发,分析了永磁直线同步电机的数学模型,提出了一种微分几何非线性最优控制的方法。通过状态反馈精确线性化把直线电动机的非线性系统转换为线性系统,并在此基础上应用非线性最优控制理论设计控制器。最后,通过MATLAB对控制系统进行仿真,仿真结果验证了此控制方法提高了系统的运动性能,增强了系统对参数摄动和外在扰动的鲁棒性。     

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。     

直流电动机的非线性控制研究

在实际应用中,直流电机本身就是一个非线性系统,它的运行状态是一个多变量、非线性、强耦合的控制对象,从电机电流和励磁的非线性变化来看,运用非线性的控制方法应该更加合理、准确。在此,以微分几何理论为基础,采用非线性控制方法,设计了一种直流电动机的输入/输出线性化控制器,并且进行了仿真,以分析其零动态特性。对被控对象精确线性化,并给出系统所需的控制规律,具有很好的调节能力和鲁棒性。     

共模反馈环路稳定性分析及电路设计

系统介绍了全差分运放中的共模反馈原理,并对采用一级共模反馈的两级运放的拓扑结构进行了分析,从而推导出了环路的稳定条件,并基于这个条件设计了一种成本低、匹配好的共模反馈电路．该电路可避免由于共模外环正反馈导致电路出现的“锁死状态”。本电路的设计基于TSMC0．5um Bi—CMOS工艺。Spectre仿真结果表明：运放工作性能良好,可稳定输出共模电平。     

海上风电直流输电的控制策略研究

海上风电场的功率输出使得新型直流输电技术成为近期研究热点之一。在分析含VSC的交直流混合输电系统模型后,得出VSC-HVDC直流输电系统的数学模型,并对系统的非线性模型进行了线性化分析,通过运用分散协调控制理论得出系统的最优控制规律,依照此规律设计了VSC-HVDC的非线性控制器。最后使用仿真软件PSCAD/EMTDC,对文中设计的非线性控制器进行了仿真研究。仿真结果表明文中采用的控制策略是有效的,并能改善输电系统的动态性能。     

基于SPWM逆变器控制系统的建模与仿真

在双环控制中,为了获得更好的控制效果,逆变器要实现状态反馈解耦。文章在状态反馈解耦的基础上,首先建立了SPWM数学模型,接着对提出的两种控制方案进行了比较,通过分析指令传函的动态跟踪性能和扰动传函的扰动抑制能力,选择了负载电流解耦的电感电流反馈,它是控制效果较好的一种方案,最后对所选的控制方案进行了系统仿真,结果表明输出电压波形质量高,动态响应好,扰动抑制能力强。     

Nonlinear control of a series DC motor: theory and experiment

The control problem for a series DC motor is considered. Based on a nonlinear mathematical model of a series-connected DC motor, it is shown that the combination of a nonlinear transformation and state feedback (feedback linearization) reduces the nonlinear control design to a linear control design. To demonstrate its effectiveness, an experimental study of this controller is presented. These experimental results are also compared with a simulation of the closed-loop system. Finally, it is shown that a nonlinear observer (with linear error dynamics) for speed and load torque can be constructed based only on measurements of the motor current. Experimental results of this speed and load-torque estimator are also presented     

三相PWM整流器的前馈解耦控制与仿真研究

基于前馈解耦控制策略,研究了三相电压型PWM整流器的建模与控制问题。首先,在d-q旋转坐标系下建立了三相电压型PWM整流器的数学模型,给出了三相电压型PWM整流器的双闭环控制结构,按此方法确定了电压、电流PI调节器的设计方法。仿真结果表明该方法能使所设计的PWM整流器运行于单位功率因数,输出的直流电压稳定在期望值且具有快速的动态响应,满足了设计要求。     

A nonlinear speed control for a PM synchronous motor using a simpledisturbance estimation technique

A nonlinear speed control for a permanent-magnet (PM) synchronous motor using a simple disturbance estimation technique is presented. By using a feedback linearization scheme, the nonlinear motor model can be linearized in the Brunovski canonical form, and the speed controller can be easily designed based on the linearized model. This technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions. An adaptive linearization technique and a sliding-mode control technique have been reported. Although good performance can be obtained, the controller designs are quite complex. To overcome this drawback, the controller parameters are estimated by using a disturbance observer theory where the disturbance torque and flux linkage are estimated. Since only the two reduced-order observers are used for the parameter estimation, the observer designs are considerably simple and the computational load of the controller for parameter estimation is negligibly small. The nonlinear disturbances caused by the incomplete linearization can be effectively compensated by using this control scheme. Thus, a desired dynamic performance and a zero steady-state error can be obtained. The proposed control scheme is implemented on a PM synchronous motor using a digital signal processor (TMS320C31) and the effectiveness is verified through the comparative simulations and experiments     

一种不依赖状态估计的自适应输出反馈控制方法

研究了一种不依赖状态估计的自适应输出反馈控制方法。首先引入伪控制信号使系统反馈线性化，然后设计一个线性动态补偿器和在线神经网络，自适应消除不确定性和建模所引起的误差。对一含有末建模动态的非线性系统的仿真结果表明，该控制方法能够消除系统的稳态误差，提高系统动态性能，并且具有较好的鲁棒性。     

Nichtlineare Trajektorienfolgeregelung für einen Laborhelikopter

This contribution is devoted to the nonlinear tracking control problem of the laboratory experiment helicopter 3DOF distributed by Quanser. The laboratory experiment belongs to the class of mechanical systems with three degrees-of-freedom and two control inputs. It is well known that the systematic design of nonlinear controllers for underactuated mechanical systems is a challenge compared to fully actuated systems. On certain simplifying assumptions, which very well apply to the operating range of practical interest, we can show that the mathematical model is configuration flat. Thereby, a mechanical system is said to be configuration flat if it is differential flat and the flat outputs solely depend on the generalized coordinates of the mechanical system. The controller design is based on a formulation of the mechanical system on a Riemannian manifold where the kinetic energy serves as a natural Riemannian metric. In a first step a nonlinear tracking controller including an integral part in the linear error system is designed by means of a quasi-static state feedback. In a second step the design of the tracking controller is based on the theory of exact linearization utilizing the so-called dynamic extension algorithm. The experimental results of both controllers are compared and discussed in detail. In particular, the quasi-static state feedback controller shows an excellent tracking behavior. The performance as being obtained by the nonlinear controlled cannot be achieved by conventional linear control strategies.     

Robust Passive Control for Uncertain Time-Delay Singular Systems

This paper investigates the problem of robust passive control for singular systems which contain structure uncertainties and time delay. Three types of controllers are considered, namely, state feedback controller, observer-based state feedback controller, and dynamic output feedback controller, and the controllers are constructed such that closed-loop systems are generalized quadratically stable and passive with dissipation $eta$. Design procedures and the algorithm are given for obtaining the maximum dissipation, and at the same time, the maximum guaranteed dissipation controllers are proposed. Illustrative examples are presented to show the validity and applicability of the proposed methods.