首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
    
A sensorless speed/position tracking control scheme for induction motors is proposed subject to unknown load torque via adaptive strictly positive real (SPR) approach design. A special nonlinear coordinate transform is first provided to reform the dynamical model of the induction motor. The information on rotor fluxes can thus be derived from the dynamical model to decide on the proportion of input voltage in the d-q frame under the constraint of the maximum power transfer property of induction motors. Based on the SPR approach, the speed and position control objectives can be achieved. The proposed control scheme is to provide the speed/position control of induction motors while lacking the knowledge of some mechanical system parameters, such as the motor inertia, motor damping coefficient, and the unknown payload. The adaptive control technique is thus involved in the field oriented control scheme to deal with the unknown parameters. The thorough proof is derived to guarantee the stability of the speed and position of control systems of induction motors. Besides, numerical simulation and experimental results are also provided to validate the effectiveness of the proposed control scheme.  相似文献   

2.
    
This paper introduces sensorless hysteresis direct torque control for permanent magnet synchronous motors to provide a reduced torque pulsation profile, which leads to a smaller mechanical vibration. The suggested algorithm utilizes the principle of vehicle steering, which continuously fixes the direction of the vehicle in the track. Moreover, the algorithm efficiently employs the output of torque and the output of flux error controllers used in basic hysteresis direct torque control to select two nonzero adjacent vectors. The initial switching time for the selected vectors is determined by a function that considers the absolute magnitude of the torque error and the magnitude of the flux error in addition to the space angle position of the stator flux. To reduce the processing time in the control signal flow, a suggested structure for switching the initial time of the selected vectors is developed. The final switching time of the vectors is adaptively adjusted according to the minimum required stator voltage to drive the load and according to the stored rotor energy that arises due to the inertia of the mechanical load connected to the motor shaft. The simulation results along with the experimental results show a fast dynamic response of torque, relatively reduced torque ripples, and reduced current harmonics compared to the basic hysteresis direct torque control.  相似文献   

3.
    
Motivated by the energy‐shaping framework and the properties of homogeneous systems, this paper deals with the problem of achieving consensus of multiple Euler‐Lagrange (EL) systems using the energy shaping plus damping injection principles of passivity‐based control. We propose a method to derive a novel family of decentralized controllers that is capable of solving the leaderless and the leader‐follower consensus problems in finite‐time in networks of fully actuated EL systems without employing velocity measurements. As in the energy‐shaping methodology, the controller is another EL system and the plant‐controller interconnection is the gradient of a suitable defined potential function. The potential energy and dissipation functions, of the controller, are provided with some homogeneous properties in order to achieve finite‐time convergence. This paper provides several simulations that corroborate the performance of different controllers.  相似文献   

4.
    
The synthesis of controllers that minimize a performance index subject to a strictly positive real (SPR) constraint is considered. Two controller synthesis methods are presented that are then combined into an iterative algorithm. Each method synthesizes optimal SPR controllers by posing a convex optimization problem where constraints are enforced via linear matrix inequalities. Additionally, each method fixes the controller state‐feedback gain matrix and finds an observer gain matrix such that an upper bound on the closed‐loop ‐norm is minimized and the controller is SPR. The first method retools the standard ‐optimal control problem by using a common Lyapunov matrix variable to satisfy both the criteria and the SPR constraint. The second method overcomes bilinear matrix inequality issues associated with the performance and the SPR constraint by employing a completing the square method and an overbounding technique. Both synthesis methods are used within an iterative scheme to find optimal SPR controllers in a sequential manner. Comparison of our synthesis methods to existing methods in the literature is presented. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

5.
在分析感应电机异步电机无速度传感器控制方法的基础上,讨论了基于模型的速度辨识方法。该速度辨识方案使用常规电流误差和新的伸缩算子来避免已知的不稳定区域,并且获得常数增益。此外还通过寄生直流成分的削除方案,以保证极低定子频率的运行,并在Matlab\Simulink环境下搭建了无速度传感器矢量控制系统的仿真模型,仿真结果证实了该方法的有效性。  相似文献   

6.
    
This article presents a new passivity‐based control law that stabilizes the output voltage of a high‐order DC‐DC converter. Such nonlinear control law assures robust large‐signal stability, provides zero steady‐state error despite uncertainty in converter parameters and has enough degree of freedom to satisfy the usual transient specifications of DC‐DC converters. This new integral control is derived in three steps. First, a static law is obtained. Second, a positive semidefinite storage function is synthesized to guarantee zero steady‐state error of the output voltage. Finally, the storage functions of the first two steps are combined to derive the new control law for high‐order DC‐DC converters. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society  相似文献   

7.
    
The by‐now standard formulation of interconnection and damping assignment passivity‐based control (for input‐affine systems) proposes the solution of a partial differential equation (PDE) that defines the assignable energy functions and computes the control using the input matrix pseudo‐inverse. However, in its original formulation—a more general design procedure was proposed, which was essentially abandoned because of the difficulties in solving the PDE. In this note, a new family of interconnection and damping assignment passivity‐based controls is proposed by extending this method in the following directions: (i) It allows the desired interconnection and damping matrices to depend on the control signal, giving the possibility to shape the PDE to ensure its solvability; (ii) the PDE directly generates the control signal that have, in general, simpler expressions; and (iii) it is applicable for general nonlinear systems possibly not affine in the control. The technique is illustrated with three examples, including the well‐known boost power converter for which it yields a simple, high‐performance controller. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

8.
    
This paper deals with the problem of control of partially known nonlinear systems, which have an open‐loop stable equilibrium, but we would like to add a PI controller to regulate its behavior around another operating point. Our main contribution is the identification of a class of systems for which a globally stable PI can be designed knowing only the systems input matrix and measuring only the actuated coordinates. The construction of the PI is carried out invoking passivity theory. The difficulties encountered in the design of adaptive PI controllers with the existing theoretical tools are also discussed. As an illustration of the theory, we consider a class of thermal processes. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

9.
    
In this paper, we propose a new passivity-based controller design technique for discrete-time fully actuated systems. The controller establishes finite-time and fixed-time convergence of dynamical system trajectories to an equilibrium state. A new form of a dissipation function, selected a priori, is introduced to design a feedback control rule to achieve such convergence properties. An energy shaping and damping injection methodology is extended to achieve non-asymptotic stabilization. A numerical example to validate the proposed methods is provided.  相似文献   

10.
    
A solution to the longstanding problem of sensorless control of an electrical machine is provided in this paper. That is, the construction of an asymptotically stable controller that regulates the mechanical speed of the motor, measuring only the electrical coordinates. The result is presented for a non‐salient permanent magnet synchronous motor perturbed by an unknown constant load torque. The proposed scheme is a fourth order nonlinear observer‐based controller that does not rely on—intrinsically nonrobust—operations like open‐loop integration of the systems dynamical model nor signal differentiation and can be easily implemented in real time. The controller is easy to commission, with the tuning gains directly determining the convergence rates of the position, speed, and load torque observers. Simulation and experimental results are presented. In particular, a comparison with a sensorless field‐oriented controller, recently proposed in the drives literature, is carried out. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

11.
    
This paper solves the asymptotic stabilization problem for a magnetically levitated flexible beam using a nested‐loop passivity‐based controller design. Passivity analyses reveal that the system can be decomposed into two passive subsystems: a mechanical subsystem that consists of a flexible beam with both ends free and that defines a passive map from external forces to the velocity of the points on the flexible beam at which the external forces act; and an electrical subsystem that consists of a pair of electromagnets and that defines a strictly output‐passive map from voltages applied across the electromagnets to magnetic fluxes. The standard method for designing passivity‐based controllers leads to a nonlinear feed‐forward controller for the electrical subsystem, which enables the electrical subsystem to generate given desired magnetic forces, and an output feedback compensator for the mechanical subsystem, which computes the desired forces required to regulate the position and vibration of the beam. The asymptotic stability of each controller may be proven using Lyapunov's stability theory and LaSalle's invariant set theorem. Numerical simulations confirm the asymptotic stability of the equilibrium configuration of the closed‐loop system formed by the magnetically levitated flexible beam together with the proposed controllers. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

12.
    
This article investigates the control problem for underactuated port‐controlled Hamiltonian systems with multiple linearly parameterized additive disturbances including matched, unmatched, constant, and state‐dependent components. The notion of algebraic solution of the matching equations is employed to design an extension of the interconnection and damping assignment passivity‐based control methodology that does not rely on the solution of partial differential equations. The result is a dynamic state‐feedback that includes a disturbance compensation term, where the unknown parameters are estimated adaptively. A simplified implementation of the proposed approach for underactuated mechanical systems is detailed. The effectiveness of the controller is demonstrated with numerical simulations for the magnetic‐levitated‐ball system and for the ball‐on‐beam system.  相似文献   

13.
    
In this article, we propose a general controller structure for asymptotic position regulation of electromechanical systems derived using the Interconnection and Damping Assignment Passivity‐Based Control methodology recently proposed in the literature. The controller is applicable to arbitrary fully actuated electromechanical systems with linear magnetic materials consisting of inductances, permanent magnets, and one mechanical co‐ordinate. We assume linear magnetic materials and fully actuated electrical dynamics; however, no restrictions are imposed on the particular form of the parameters that define the system dynamics, i.e. the inductance matrix, the magnetic coupling or the potential energy function. This allows us to treat—in a unified framework and without any additional simplifying assumptions—very diverse applications, including magnetic suspensions, and stepper and permanent magnet synchronous motors. Instrumental for our developments is the inclusion of ‘virtual’ couplings between the electrical and the mechanical subsystem, which is naturally suggested in this control methodology. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

14.
This paper reports the basic concept and recent industrial applications of a sensorless vector-controlled speed-control system for an inverter-fed induction motor in Japan. The vector control artificially gives the linear torque controllability, which is inherent for a separately excited DC motor, to the induction motor drive. First, in this paper, the fundamental concept of vector control is introduced. Next, representative speed-sensorless vector-control systems will be related. Also, a method for the automatic measurement of the electrical parameters of the induction motor is introduced. To know the motor parameters precisely is especially important for a speed-sensorless vector-control system. Finally, several examples of industrial applications of the sensorless speed control are described.  相似文献   

15.
In this paper, we design an output‐feedback, rotor position/rotor flux controller for the full‐order, nonlinear dynamic model of an induction motor. The singularity free controller does not require measurement of rotor flux or rotor velocity and yields global exponential rotor position and rotor flux tracking. The proposed controller is termed output‐feedback due to the inexpensive/simplistic manner in which stator current measurements can be obtained (e.g., the most primitive method of measuring current can be achieved through simple voltage measurements across known resistive elements). Experimental results are included to verify the effectiveness of the proposed controller.  相似文献   

16.
    
The problem of robustification of interconnection and damping assignment passivity‐based control for underactuated mechanical system vis‐à‐vis matched, constant, and unknown disturbances is addressed in the paper. This is achieved adding an outer‐loop controller to the interconnection and damping assignment passivity‐based control. Three designs are proposed, with the first one being a simple nonlinear PI, while the second and the third ones are nonlinear PIDs. While all controllers ensure stability of the desired equilibrium in spite of the presence of the disturbances, the inclusion of the derivative term allows us to inject further damping enlarging the class of systems for which asymptotic stability is ensured. Numerical simulations of the Acrobot system and experimental results on the disk‐on‐disk system illustrate the performance of the proposed controller. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

17.
基于DSP的自适应速度辨识直接转矩控制系统研究   总被引:4,自引:1,他引:4  
异步电机直接转矩控制能产生快速且良好的鲁棒性响应,采用自适应磁链观测器,取代传统的积分器,构造了新型的速度估计器,并结合模糊控制器,实现对定子磁链准确观测和系统无速度传感器运行状态。基于DSP(TMS320LF2407A)核心芯片建立数字化控制系统。仿真与实验表明,该系统对电机定子磁链的观测精度高,转速估算准确,尤其在低速下能保持很高的性能。  相似文献   

18.
    
In this article, a sensorless output feedback controller is designed in order to drive the induction motor (IM) without the use of flux and speed sensors. First, an observer that uses only the measured stator currents is synthesised to estimate the mechanical variables (speed and load torque) and the magnetic variables (fluxes) by structurally taking into account the unobservability phenomena of the sensorless IM (SIM) and the parametric uncertainties. Second, a current-based field-oriented sliding mode control that uses the flux and the speed estimates given by the former observer is developed so as to steer the estimated speed and flux magnitude to the desired references. Since the observer error dynamic is independent from the known input control and depends on the IM parametric uncertainties, a kind of separation principle is introduced to guarantee the practical stability of the whole closed-loop system ‘observer–controller’ (‘O-C’) according to observability and unobservability time variation. A significant benchmark taking into account the unobservability phenomena of the SIM is presented to show the performances of the whole control scheme against experimental set-up.  相似文献   

19.
    
This paper is concerned with the problem of feedback passification for switched stochastic time‐delay systems with multiple disturbances subject to mode‐dependent average dwell‐time switching. The multiple disturbances are composed of two parts: one is given through an exogenous system and the other is described in the form of norm‐bounded vector. A disturbance observer is constructed to estimate an exogenous disturbance. Then, a state feedback controller that includes the estimation value is designed to guarantee the passivity of the closed‐loop system. The observer and controller gains are developed via linear matrix inequalities. The effectiveness of the proposed method is verified through a numerical example and an application example to PWM‐driven boost converter.  相似文献   

20.
    
In this paper two new schemes for induction motor control are proposed and compared. Both approaches are based on the concept of adaptive passivity. First, a technique using the scheme of field oriented control (FOC) is proposed, and by means of an adaptive state feedback, a passive equivalent system is obtained. Furthermore, making use of the novel torque‐flux control principle (TFCP), the proposed scheme is greatly simplified. Second, a technique based on energy shaping approach, which does not make use of the FOC scheme, is proposed. The technique is based on interconnection and damping assignment (IDA) control transforming the original system into a passive one. Since this technique does not use the FOC scheme, it gives more flexibility in the implementation. Both techniques are then implemented at laboratory level and compared from experimental viewpoint using as benchmark the standard FOC scheme with PI controllers. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号