Speed tracking control of a permanent-magnet synchronous motor withstate and load torque observer

This paper is concerned with the speed tracking control problem for a permanent-magnet synchronous motor (PMSM) in the presence of an unknown load torque disturbance. After a brief review of the mathematical model of the PMSM, a speed tracking control law using the exact linearization methodology is introduced. The tracking control algorithm is completed by adding an extended observer which provides, on the one hand, the motor speed and acceleration and, on the other hand, estimates the unknown load torque. The stability of the closed-loop system composed of a nonlinear speed tracking controller and an observer is studied by the way of Lyapunov theory. Furthermore, the decoupling of the state observer and the load torque observer is discussed. Finally, a real-time implementation and the experimental results of the proposed control strategy are presented     

Adaptive positioning control for a LPMSM drive based on adapted inverse model and robust disturbance observer

The adaptive robust positioning control for a linear permanent magnet synchronous motor drive based on adapted inverse model and robust disturbance observer is studied in this paper. First, a model following two-degrees-of-freedom controller consisting of a command feedforward controller (FFC) and a feedback controller (FBC) is developed. According to the estimated motor drive dynamic model and the given position tracking response, the inner speed controller is first designed. Then, the transfer function of FFC is found based on the inverse model of inner speed closed-loop and the chosen reference model. The practically unrealizable problem possessed by traditional feedforward control is avoided by the proposed FFC. As to the FBC, it is quantitatively designed using reduced plant model to meet the specified load force regulation control specifications. In dealing with the robust control, a disturbance observer based robust control scheme and a parameter identifier are developed. The key parameters in the robust control scheme are designed considering the effect of system dead-time. The identification mechanism is devised to obtain the parameter uncertainties from the observed disturbance signal. Then by online adapting the parameters set in the FFC according to the identified parameters, the nonideal disturbance observer based robust control can be corrected to yield very close model following position tracking control. Meanwhile, the regulation control performance is also further improved by the robust control. In the proposed identification scheme, the effect of a nonideal differentiator in the accuracy of identification results is taken into account, and the compromise between performance, stability, and control effort limit is also considered in the whole proposed control scheme.     

Design and Implementation of a Robust Current-Control Scheme for a PMSM Vector Drive With a Simple Adaptive Disturbance Observer

This paper introduces a robust current-control scheme for a permanent-magnet synchronous motor (PMSM) with a simple adaptive disturbance observer. The robust controller is realized by including an adaptive element in the reference-voltage-generation stage using the feedforward control. Due to the time-varying nature and the high-bandwidth property of the uncertainties in a practical PMSM drive system, the adaptive element is simply chosen as the estimated uncertainty function, which adaptively varies with different operating conditions. Subsequently, the frequency modes of the uncertainty function are embedded in the control effort, and a robust current-control performance is yielded. Furthermore, the inclusion of the estimated uncertainty function provides an efficient solution for torque-ripple minimization in PMSM drives. This is because the frequency modes of the disturbances to be eliminated, i.e., the flux harmonics, are included in the stable closed-loop system. To provide a high-bandwidth estimate of the uncertainty function, a simple adaptation law is derived using the nominal current dynamics and the steepest descent method. To guarantee the system's convergence and to properly tune the proposed observer, a stability analysis based on a discrete-time Lyapunov function has been used. Comparative evaluation experiments are presented to demonstrate the effectiveness of the proposed control scheme under different operating conditions.     

An optimal speed controller for permanent-magnet synchronous motordrives

An optimal control system synthesis method which can achieve vector and speed control simultaneously for permanent-magnet synchronous motor (PMSM) drives is proposed in this paper. A state-space multiple-input-multiple-output (MIMO) model for PMSM is first developed and the compensation for the nonlinearities in this model is discussed. A pseudo-linearized PMSM model is dynamically constructed through the state detection, and subsequently an optimal speed controller is developed based on this linearized model. The integral control technique is incorporated to eliminate possible speed offsets. A speed observer is further developed to eliminate the speed sensor from the drive     

Fuzzy adaptive speed control of a permanent magnet synchronous motor

A fuzzy adaptive speed controller is proposed for a permanent magnet synchronous motor (PMSM). The proposed fuzzy adaptive speed regulator is insensitive to model parameter and load torque variations because it does not need any accurate knowledge about the motor parameter and load torque values. The stability of the proposed control system is also proven. The proposed adaptive speed regulator system is implemented by using a TMS320F28335 floating point DSP. Simulation and experimental results are presented to verify the effectiveness of the proposed fuzzy adaptive speed controller under uncertainties such as motor parameter and load torque variations using a prototype PMSM drive system.     

时变扰动下的永磁同步电机滑模控制

时变扰动环境下,永磁同步电机(PMSM)采用鲁棒性较好的滑模控制。根据滑模控制中传统指数趋近律,提出一种改进型的趋近律,并基于改进型趋近律设计了一种PMSM调速系统的滑模速度控制器,提高电机的运行性能。通过仿真结果对比分析,设计的基于改进型趋近律的滑模速度控制器不仅可以提高系统的动态性能,而且削弱了系统的抖振现象,使电机在时变扰动下仍具有较高的运行性能。     

A Hybrid-Type Variable-Structure Instantaneous Torque Control With a Robust Adaptive Torque Observer for a High-Performance Direct-Drive PMSM

This paper describes a novel instantaneous torque control scheme for a high-performance direct-drive permanent-magnet synchronous motor. The scheme consists of a robust adaptive instantaneous torque observer and a hybrid-type variable-structure instantaneous torque controller. First, to robustly obtain the instantaneous electromagnetic torque information, a robust adaptive torque observer is designed by considering all possible current model uncertainties. The observation gains and uncertainties prediction rules are derived in the sense of Lyapunov theory so that the stability of the proposed estimation scheme is fulfilled. Second, to ensure perfect tracking of the output torque and providing means in eliminating torque ripples, the frequency modes of the disturbances to be eliminated should be included in the stable closed-loop system. To achieve this objective, a hybrid-type variable-structure controller with internal model, for the flux harmonics and system uncertainties, is adopted. The hybrid controller shows better disturbance rejection without control chattering. Comparative evaluation results are presented to demonstrate the validity and effectiveness of the proposed instantaneous torque control scheme.     

Control Algorithms for a Fault-Tolerant PMSM Drive

This paper proposes control algorithms for a fault-tolerant permanent-magnet synchronous motor (PMSM) drive. In order to improve the reliability of the drive, an algorithm for achieving a sensorless control that operates properly also in fault mode is proposed. Furthermore, it is shown how a closed-loop field-weakening controller needs to be modified in order to operate properly in fault mode. Automotive applications are in mind and the algorithms presented are verified with experimental results using an in-wheel PMSM. With the proposed modifications, the reliability of the drive can be improved.     

Decoupled stator-flux-oriented induction motor drive with fuzzyneural network uncertainty observer

A stator-flux-oriented induction motor drive using online rotor time-constant estimation with a robust speed controller is introduced in this paper. The estimation of the rotor time constant is made on the basis of the model reference adaptive system using an energy function. The estimated rotor time-constant is used in the current-decoupled controller, which is designed to decouple the torque and flux in the stator-flux-field-oriented control. Moreover, a robust speed controller, which is comprised of an integral-proportional speed controller and a fuzzy neural network uncertainty observer, is designed to increase the robustness of the speed control loop. The effectiveness of the proposed control scheme is demonstrated by simulation and experimental results     

An improved sensorless vector-control method for an induction motor drive

In the present paper, a new improved sensorless vector-control method for an induction motor drive is presented. The proposed method is based on an improved closed-loop stator-flux estimator, based on the dynamic model of the asynchronous motor, which achieves precise stator-flux estimation over a wide area of operation. This new stator-flux estimator ensures stability of the overall control scheme in a very-wide-speed operation area, as it will be shown in this paper. The rotor-speed-estimation method is based on an observer based on the model reference adaptive systems (MRAS) theory. The control scheme is based on a stator-flux-oriented direct vector-control method, where both flux and speed controllers are optimal tuned. In addition, implementation of the proposed method is based on a simplified algorithm capable of running in a low-cost microcontroller, which is discussed in detail. Also, the motor-drive system, including the stator-flux estimator, the speed estimator, and the control logic are simulated and some characteristic simulation results are presented. These results reveal that the proposed method is able to obtain precise flux and speed control over a wide operation area, including very low operating frequencies.     

On Sensorless Induction Motor Drives: Sliding-Mode Observer and Output Feedback Controller

In this paper, a sensorless output feedback controller is designed in order to drive the induction motor (IM) without the use of flux and speed sensors. First, a new sliding-mode observer that uses only the measured stator currents is synthesized to estimate the speed, flux, and load torque. Second, a current-based field-oriented sliding-mode control is developed so as to steer the estimated speed and flux magnitude to the desired references. A stability analysis based on the Lyapunov theory is also presented in order to guarantee the closed-loop stability of the proposed observer-control system. Two experimental results for a 1.5-kW IM are presented and analyzed by taking into account the unobservability phenomena of the sensorless IM.      

基于DSP和FPGA的望远镜伺服控制系统设计

针对交流永磁同步电机驱动的大型望远镜的高精度、低速平稳运行问题,研制了一套基于浮点数字信号处理器（DSP）和现场可编程逻辑门阵列（FPGA）的驱动控制器。该控制器以DSP 作为主控制器,FPGA 作为协控制器,主控制器完成控制算法、接受指令等功能,协控制器实现PWM 产生、电流采集、速度检测等功能。根据永磁同步电机矢量控制原理建立了永磁同步电机的数学模型,进行了永磁同步电机控制器的硬件设计;在硬件设计的基础上,采用自适应PI 对望远镜的低速控制性能进行了研究。实验结果表明:当望远镜以32.4 （）/s 匀速运行时,速度波动范围为0.648 （）/s;当对望远镜做最大速度为1（）/s,最大加速度为1（）/s2 的正弦引导时,最大引导误差为9.72 ,引导误差RMS 值为3.24 ;该驱动控制系统能够实现望远镜的低速平稳运行,满足大型望远镜伺服控制系统的性能要求。     

A fault-tolerant control architecture for induction motor drives in automotive applications

This paper describes a fault-tolerant control system for a high-performance induction motor drive that propels an electrical vehicle (EV) or hybrid electric vehicle (HEV). In the proposed control scheme, the developed system takes into account the controller transition smoothness in the event of sensor failure. Moreover, due to the EV or HEV requirements for sensorless operations, a practical sensorless control scheme is developed and used within the proposed fault-tolerant control system. This requires the presence of an adaptive flux observer. The speed estimator is based on the approximation of the magnetic characteristic slope of the induction motor to the mutual inductance value. Simulation results, in terms of speed and torque responses, show the effectiveness of the proposed approach.     

基于重复滑膜控制的PMSM的矢量控制系统

针对永磁同步电机(PMSM)在负载突变时产生的抖振现象,文中提出了一种重复滑模控制方法。首先,详细介绍了永磁同步电机的数学模型和滑膜变结构的基本原理,并在PMSM速度环上采用滑膜控制方法代替传统的PI控制。其次,具体分析了重复控制的基本原理,在滑膜控制的基础上加入重复控制,提出了一种新型的重复滑膜控制策略,建立了基于MATLAB/Simulink的电机仿真模型。仿真结果表明,此控制方法在电机转速上升阶段具有较好的系统响应性;在电机突加负载时,电机转速最大突变值比使用滑膜控制时减少了74.55%,且电机恢复到稳定状态用时为使用滑膜控制时的37.5%;验证了所提出的重复滑膜控制方法具有较强的抗负载性和系统稳定性。     

Sensorless speed control of nonsalient permanent-magnet synchronous motor using rotor-position-tracking PI controller

This paper presents a new velocity estimation strategy of a nonsalient permanent-magnet synchronous motor (PMSM) drive without a high-frequency signal injection or special pulsewidth-modulation (PWM) pattern. This approach is based on the d-axis current regulator output voltage of the drive system that has the information of rotor position error. Rotor velocity can be estimated through a rotor-position-tracking proportional-integral (PI) controller that controls the position error to zero. For zero and low-speed operation, the PI controller gains of rotor position tracking controller have a variable structure according to the estimated rotor velocity. In order to boost the bandwidth of the PI controller around zero speed, a loop recovery technique is applied to the control system. The proposed method only requires the flux linkage of the permanent magnet and is insensitive to parameter estimation error and variation. The designers can easily determine the possible operating range with a desired bandwidth and perform vector control even at low speeds. The experimental results show the satisfactory operation of the proposed sensorless algorithm under rated load conditions.     

Robust motion controller design for high-accuracy positioningsystems

This paper presents a controller structure for robust high speed and accuracy motion control systems. The overall control system consists of four elements: a friction compensator; a disturbance observer for the velocity loop; a position loop feedback controller; and a feedforward controller acting on the desired output. A parameter estimation technique coupled with friction compensation is used as the first step in the design process. The friction compensator is based on the experimental friction model and it compensates for unmodeled nonlinear friction. Stability of the closed-loop is provided by the feedback controller. The robust feedback controller based on the disturbance observer compensates for external disturbances and plant uncertainties. Precise tracking is achieved by the zero phase error tracking controller. Experimental results are presented to demonstrate performance improvement obtained by each element in the proposed robust control structure     

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     

基于TMS320F2812的永磁同步电机双闭环矢量调速系统

根据永磁同步电机的数学模型和坐标变换的原理,介绍了矢量调速系统,利用数学方程推导了电流环和速度环PI控制器的传递函数和参数解析计算式。基于TMS320F2812平台,结合实际系统,考虑误差和参数补偿,完成双闭环调速系统的设计。实验结果表明,该永磁同步电机双闭环矢量调速系统能够稳定运行,并有良好的控制性能,快速、准确完成闭环调速功能。     

Observer-Based Ripple Force Compensation for Linear Hybrid Stepping Motor Drives

This paper describes our research on a force ripple compensation and closed-loop position control scheme using linear hybrid stepping motors (LHSMs) with significant thrust vibrations. In order to estimate unobservable force ripple components, we propose the Jacobian linearization observer that guarantees the convergence of state estimates into true states. For the precise control of velocity and position, an input-output feedback linearization controller is derived from a nonlinear position-dependent model of the LHSM based on elaborate reluctance network analysis. In addition, we discuss the separation principle used to separate the observer design from the controller design. Common problems associated with the force ripple, such as the positioning error, mechanical stress, and acoustic noise, are efficiently handled using the proposed active damping control scheme. Experimental results show that the positioning accuracy is significantly improved through a closed-loop control while restraining the thrust ripple.     

High performance ultra-low speed servo system based on doubly coprime factorization and instantaneous speed observer

This paper proposes a new speed servo system for a wide speed range based on doubly coprime factorization and instantaneous speed observer. The proposed speed controller is a new two-degrees-of-freedom speed servo system considering the robust stability according to inertia variation, which is designed on the basis of doubly coprime factorization and disturbance observer. In an ultra-low speed range, a speed sensor based on a rotary encoder cannot detect a motor speed. In this paper, a speed information in a very low speed range is estimated by the proposed instantaneous speed observer which mounts the parameter identification algorithm to cancel out the estimation error caused by parameter variation. Therefore, the two-degrees-of-freedom speed servo system connecting the instantaneous speed observer regulates a motor speed robustly in a wide speed range including an ultra-low speed range, and it keeps the desired speed response for all speed reference including an ultra-low speed range.