DTFC-SVM motion-sensorless control of a PM-assisted reluctance synchronous machine as starter-alternator for hybrid electric vehicles

Permanent magnet-assisted reluctance synchronous machine (PM-RSM) starter alternator systems are credited with good performance for wide speed range in hybrid electric vehicles. This paper proposes a motion-sensorless motor/generator control of PM-RSM from zero speed up to maximum speed, using direct torque and flux control with space vector modulation. A quasioptimal stator flux reference with a flux versus torque functional is proposed. A stator flux observer in wide speed range uses combined voltage-current models for low speeds, and only the voltage model for medium to high speeds, both in proportional-integral closed loop. A novel rotor speed and position observer with a fusion strategy employs signal injection and only one D-module vector filter in stator reference for low speed, combined with a speed observer from the stator flux vector estimation-for medium-high speed. The proposed system is introduced piece by piece and then implemented on a dSpace 1103 control board with a 350-A metal-oxide-semiconductor field-effect transistor-pulse-width modulation converter connected to a 42-Vdc, 55-Ah battery, and a 140-Nm peak torque PM-RSM. Extensive experimental results from very low speed to high speed, regarding observers and drive responses, including artificial loading (motoring and generating), seem very encouraging for future starter-alternator systems.     

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     

Control strategies for power smoothing using a flywheel driven by a sensorless vector-controlled induction machine operating in a wide speed range

This paper presents a novel control strategy for power smoothing. The system is based on a sensorless vector-controlled induction machine driving a flywheel. The problem of regulating the DC-link voltage against input power surges or sudden changes in load demand is addressed. The induction machine is controlled to operate in a wide speed range by using flux weakening above rated speed. A model reference adaptive system observer is used to obtain the rotational speed in the whole speed range. The observer parameters are adapted during flux weakening in order to obtain close tracking of the flywheel speed. Experimental results for the operation of the induction machine between zero to more than twice base speed are presented and discussed.     

异步电机自适应矢量控制系统研究

提出了一种速度自适应的转子磁链闭环观测器,并应用于矢量控制系统中,以取代传统的纯积分器。经过理论证明,该系统是超稳定系统。针对1.1kW感应电机,采用MATLAB／SIMULINK仿真软件对系统进行仿真,仿真结果表明该方案对电机参数变化的鲁棒性较好,磁链观测精度高。同时,基于磁链状态观测器设计的速度辨识方案收敛速度快．精度高,尤其是在较低转速下仍能保持很高的精度。     

A self-tuning closed-loop flux observer for sensorless torquecontrol of standard induction machines

This paper proposes a self-tuning closed-loop flux observer, which provides field-oriented torque control for induction machines without a tachometer. The proposed algorithm combines the best features of harmonic detection and stator voltage integration through the use of a new tuning scheme. The observer accuracy and robustness is augmented by a parameter-independent accurate-speed detector, which analyzes magnetic saliency harmonics in the stator current. The harmonic-detection scheme provides accurate rotor-speed updates during steady-state operation down to 1-Hz source frequency. This additional speed information is used to tune the rotor-resistance parameter of the observer. The tuned observer exhibits improved dynamic performance, accurate steady-state speed control and an extended range of control near zero speed. The algorithm requires no special machine modifications and can be implemented on most existing low- and medium-performance drives. The closed-loop nature of the flux observer, combined with the harmonic-detection scheme, provides flux and speed error feedback, which significantly increases the robustness of sensorless control across the entire speed range     

Robust control using neural network uncertainty observer for linearinduction motor servo drive

A robust controller, that combines the merits of integral-proportional (IP) position control and neural network (NN) observed technique, is designed for a linear induction motor (LIM) servo drive in this study. First, the secondary flux of the LIM is estimated using a sliding-mode flux observer on the stationary reference frame and the feedback linearization theory is used to decouple the thrust and the flux amplitude of the LIM. Then, the IP position controller is designed according to the estimated mover parameters to match the time-domain command tracking specifications. Moreover, a robust controller is formulated using the NN uncertainty observer, which is implemented to estimate the lumped uncertainty of the controlled plant, as an inner-loop force controller to increase the robustness of the LIM servo drive system. Furthermore, in the derivation of the online training algorithm of the NN, an error function is used in the Lyapunov function to avoid the real-time identification of the system Jacobian. In addition, to increase the speed and accuracy of the estimated flux, the sliding-mode flux observer is implemented using a 32 bit floating-point digital signal processor (DSP) with a high sampling rate. The effectiveness of the proposed control scheme is verified by both the simulated and experimental results     

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     

An Adaptive Sliding Stator Flux Observer for a Direct-Torque-Controlled IPM Synchronous Motor Drive

This paper focuses on performance improvements of the stator flux estimation for a direct-torque-controlled interior permanent magnet synchronous motor drive. In this paper, an adaptive sliding observer is presented to estimate the stator flux linkage based on the motor current model. The experimental results show that the proposed observer has been able to deliver more accurate estimation than an open-loop estimator both in the steady state and during transients. The observer has better dynamic behavior, disturbance resistance, and high-accuracy estimation ability. With the integrated flux observer, the drive system can operate at very low speed down to 10 r/min (0.33 Hz) with half full load.     

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     

异步电机全阶自适应磁链观测和速度辨识

针对传统的直接转矩控制系统采用纯积分的电压模型作为磁链观测器,存在着误差积累以及直流偏移,导致电流和转矩的波动问题,提出了一种基于定子磁链的自适应全阶观测器的直接转矩控制系统,并实现了速度辨识。仿真实验表明：采用自适应磁链观测器具有较高的观测精度和较好的鲁棒性。     

基于改进的电流模型磁链观测器的异步电机矢量控制

本文首先讲述了交流调速的现状,阐述了矢量控制原理,采用转子磁链定向搭建磁链电流模型,最后搭建了带转矩内环的转速、磁链闭环矢量控制系统仿真模型。使用MATLAB仿真软件进行了仿真,并在原来仿真基础上修改了相关仿真参数,结果验证了基于电流模型磁链观测器的矢量控制策略的优越性能。     

Sliding-mode MRAS speed estimators for sensorless vector control of induction Machine

This paper presents two novel sliding mode (SM) model reference adaptive system (MRAS) observers for speed estimation in a sensorless-vector-controlled induction-machine drive. Both methods use the flux estimated by the voltage model observer as the reference and construct SM flux observers that allow speed estimation. Stability and dynamics of the two proposed SM flux observers are discussed. The observers are compared with the classical MRAS observer. The proposed estimators seem very robust and easy to tune. Unlike the classical MRAS, the speed-estimation process is based on algebraic calculations that do not exhibit underdamped poles or zeros on the right-hand plane. Simulations and experimental results on a 1/4-hp three-phase induction machine confirm the validity of the approaches.     

Speed-sensorless sliding-mode torque control of an induction motor

Novel induction motor control optimizing both torque response and efficiency is proposed in the paper. The main contribution of the paper is a new structure of rotor flux observer aimed at the speed-sensorless operation of an induction machine servo drive at both low and high speed, where rapid speed changes can occur. The control differs from the conventional field-oriented control. Stator and rotor flux in stator fixed coordinates are controlled instead of the stator current components in rotor field coordinates i_sd and i_sq. In principle, the proposed method is based on driving the stator flux toward the reference stator flux vector defined by the input command, which are the reference torque and the reference rotor flux. The magnitude and orientation angle of the rotor flux of the induction motor are determined by the output of the closed-loop rotor flux observer based on sliding-mode control and Lyapunov theory. Simulations and experimental tests are provided to evaluate the consistency and performance of the proposed control technique     

Adaptive pseudoreduced-order flux observer for speed sensorlessfield-oriented control of IM

An adaptive pseudoreduced-order flux observer for speed sensorless field-oriented control is presented. In comparison with the adaptive full-order flux observer, the proposed method consumes less computational time and illustrates better speed performance. Simulations and experiments on a 3-hp induction motor verify the validity of the proposed method     

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.     

Hybrid rotor position observer for wide speed-range sensorless PM motor drives including zero speed

This paper addresses the problem of wide speed-range sensorless control of a surface-mount permanent-magnet (SMPM) machine including zero-speed operation. A hybrid structure integrating a flux observer and signal-injection techniques is proposed, which results in a rotor position signal independent of motor parameters at low and zero speed. Although the SMPM machine typically has a very low geometric saliency, the injection technique is effective in tracking the saturation-induced saliency produced by the stator flux. Experimental results are presented showing an excellent performance for both the sensorless speed and position control using an off-the-shelf SMPM machine.     

New sensorless vector control using minimum-order flux state observer in a stationary reference frame for permanent-magnet synchronous motors

This paper proposes a new sensorless vector control method that can be applied to both of salient-pole and nonsalient-pole permanent-magnet synchronous motors (PMSMs). The proposed method estimates the phase of a rotor flux by a newly developed state observer in a stationary reference frame for sensorless vector controls of PMSMs. The flux state observer has the following attractive features: 1) it requires no steady-state conditions for the dynamic mathematical model of the motor; 2) its order is the minimum second; 3) a single observer gain is simply constant over a wide operating range and can be easily designed; 4) it utilizes motor parameters in a very simple manner; and 5) its structure is very simple and can be realized at a very low computational load. The proposed speed-estimation method, which exploits the inherent physical relation of integration/derivation between phase and speed, is very simple and can properly estimate rotor speed. The usefulness of the proposed method is examined and confirmed through extensive experiments.     

基于Matlab／Simuljnk的无速度传感器直接转矩控制的仿真

本文介绍了异步电动机直接转矩控制的基本原理，提出了基于自适应全阶磁链观测器的速度估算方法，实现了无速度传感器的速度辨识。并应用Matlab／Simulink软件对该系统进行了建模和仿真，仿真结果表明，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。     

基于MRAS的无速度传感器异步电机矢量控制研究

本文依据异步电机矢量控制的基本原理,构建了无速度传感器的矢量控制系统。该系统中采用了转子磁链观测器方法,并运用模型参考自适应法进行了转子速度的估计。文中通过了Matlab/Simulink构建系统仿真模型,结果表明了系统的正确性与可行性。     

基于全阶观测器的异步电动机矢量控制系统

磁链观测一直是异步电机无速度矢量控制的难点,本文以异步电动机本身为参考模型,设计了全阶观测器的可调模型来估算异步电机的磁链和速度。利用Matlab软件构造了按转子磁场定向的矢量控制系统的仿真模型,采用全阶观测器的方法在逆变器仿真平台和实验平台上实现了异步机的无速度矢量控制。通过仿真和试验验证了模型的正确性,结果表明所建立的调速系统具有良好的动态性能。