Adaptive control for speed‐sensorless induction motors with uncertain load torque and rotor resistance

The problem of controlling a speed‐sensorless induction motor is addressed. Smooth reference signals for rotor speed and flux modulus are required to be tracked for any unknown constant values of load torque and rotor resistance within known bounds. A fourth order non‐linear adaptive tracking control is presented which is based on a novel rotor speed observer and on two identifiers for the uncertain parameters; it guarantees asymptotic rotor speed tracking and exponential rotor flux modulus tracking with an explicitly computed domain of attraction. The closed‐loop performances are illustrated by simulation. Copyright © 2005 John Wiley & Sons, Ltd.     

感应电机系统的非线性反推自适应控制

针对感应电机的动态特性,在电机参数未知的前提下,研究了磁链与转速的渐近跟踪特性和整个系统的全局稳定性问题.应用反推技术设计了自适应控制器,对所有参数进行估计,实现了电机对给定信号的输出跟踪控制,保证了整个系统的全局稳定性.系统的转子磁链与转速能渐近跟踪给定的参考信号,仿真结果验证了该控制策略的有效性.     

基于无源性的同步电机自适应滑模控制方法

利用本质上是非线性反馈的无源性控制(PBC)策略,实现同步电机的全局稳定和转矩、转速跟踪控制.建立了同步电机的Euler-Lagrange模型;在此基础上利用无源性滑模控制方法构建转矩、转速动态跟踪控制器,在非线性负载时变未知情形下,实现了转子磁链、转速的期望轨迹渐近跟踪;针对实际运行时同步电机参数具有不确定性的问题,...     

基于磁链与负载观测器的异步电机反步滑模控制

针对参数摄动及负载转矩未知且变化会影响异步电机速度控制的问题,设计了一种改进型指数趋近律的滑模转子磁链观测器,用于估算电机转子磁通值,同时将磁通观测值用于负载转矩的估计。引入磁链误差、转速误差,通过反步滑模控制算法,将转子磁通与负载转矩的观测值用于异步电机控制。在转子电阻摄动与负载转矩未知且变化的情况下,将该控制策略与自适应反步控制方法进行实验结果对比。实验结果表明,该控制策略的响应速度快且跟踪精度高,提高了异步电机速度控制系统的抗干扰性能。最后,提出一种转速软给定方法,实验表明该方法能有效抑制转速变化时刻定子电流与电磁转矩的急剧增加,进一步改善了电机系统的性能。     

Non‐linear adaptive control of induction motors

Given measurements of rotor position, rotor velocity, and stator currents, we design an adaptive control scheme that is free of singularities, does not require rotor flux measurements, and provides for simultaneous asymptotic rotor position/rotor flux tracking despite the uncertainty associated with the mechanical subsystem parameters and the rotor resistance parameter. For the case when the rotor resistance parameter is known exactly, we modify the structure of the controller to achieve global asymptotic rotor position/rotor flux tracking while accommodating for parameter uncertainty associated with the mechanical subsystem parameters and the stator electrical subsystem parameters. Experimental results are presented to illustrate the performance of the control structure. Copyright © 1999 John Wiley & Sons, Ltd.     

Global adaptive linear control of the permanent‐magnet synchronous motor

We contribute with a linear time‐varying controller for the permanent magnet synchronous motor. We solve the open problem of speed‐tracking control by measuring only stator currents and the rotor angular positions, under parametric uncertainty. Integral action is used to compensate for the effects of the unknown load‐torque, and adaptation is employed to estimate the unknown parameters. In the case that parameters are known (except for the load), we show that the origin of the closed‐loop system is uniformly globally exponentially stable. For the case of unknown parameters, we prove uniform global asymptotic stability; hence, we establish parametric convergence. In contrast to other adaptive control schemes for electrical machines, we use a reduced‐order adaptive controller. Indeed, adaptation is used only for the electrical dynamics equations. Moreover, not surprisingly, the closed‐loop system has a structure well‐studied in adaptive‐control literature. Performance is illustrated in a numerical setting. Copyright © 2013 John Wiley & Sons, Ltd.     

Adaptive sliding mode observer for induction motor using two-time-scale approach

This paper presents an original method for the design of a robust adaptive sliding mode current and flux observer for induction motor drive using two-time-scale approach. This approach, based on the singular perturbation theory, decomposes the original system of the observer error dynamics into separate slow and fast subsystems of lower dimensions and permits a simple design and sequential determination of the observer gains. For the proposed observer, the rotor speed signal is assumed to be available. The stator currents and rotor flux are observed on the stationary reference frame using sliding mode concept, and the adaptive rotor time-constant is derived from Lyapunov stability theory using measured and estimated currents and estimated rotor flux. The control algorithm is based on the indirect field-oriented sliding mode control to keep the machine field oriented. The control-observer scheme seeks to provide asymptotic tracking of speed and rotor flux in spite of the presence of an uncertain load torque and unknown value of the rotor resistance. The effectiveness of this control algorithm has been successfully verified through computer simulations.     

负载转矩和转子电阻未知任意情形下感应电机转矩无源性跟踪控制

应用无源性控制方法研究了在负载转矩和转子电阻为未知时变情形下感应电机期望转矩的跟踪控制问题。基于感应电机的Euler-Lagrange(E-L)模型,通过设计控制器、期望轨道、期望转矩、转子电阻估计器、负载转矩估计器、转子状态观测器,在理论上证明了可以实现对任意时变期望转矩的渐近跟踪,以及对负载转矩和转子电阻的快速估计。基于MATLAB/Simulink的仿真结果,证明了理论结果的正确性、有效性和高性能。     

自适应FC的无速度传感器感应电机矢量控制系统

设计了一种二维自适应模糊控制器(FC)作为无速度传感器感应电机矢量控制系统的速度调节器.这种自适应模糊控制器可以根据速度给定和负载转矩的变化实时调节解模糊的比例因子.系统使用定转子自适应磁通观测器和转速动态估计器来估算转子磁通和转速,有两个PID控制器分别控制转矩和磁通的电流分量,输出电压空间矢量控制电机.仿真结果表明,与PID控制器比较,FC具有更好的动态性能和稳态性能,鲁棒性得到很大提高.     

无速度传感器的感应电机神经网络鲁棒自适应控制

针对感应电机定子电阻和负载转矩参数的不确定性,提出了无速度传感器的感应电机神经网络鲁棒自适应控制方案。用反步法设计了一种可以将各状态变量跟踪误差和神经网络各权值限制在规定范围内的神经网络鲁棒自适应控制器,提出了相应的算法,用Lyapunov定理对其稳定性进行了证明。提出了一种可以估算转子磁链和转速的观测器及相应的算法。仿真研究表明,所提出的感应电机无速度传感器控制方案对电机定子电阻、负载转矩的鲁棒性强,动态性能好,速度估算较精确。     

Robust sliding mode control and flux observer for induction motor using singular perturbation

This paper proposes a sequential methodology for designing a robust adaptive sliding mode observer for an induction motor drive using a two-time-scale approach. This approach is based on the singular perturbation theory. The two-time-scale decomposition of the original system of the observer error dynamics into separate slow and fast subsystems permits a simple design and sequential determination of the observer gains. In the proposed method, the stator currents and rotor flux are observed on the stationary reference frame using the sliding mode concept. The control algorithm is based on the indirect field oriented sliding mode control with an on-line adaptation of the rotor resistance to keep the machine field oriented. The control–observer scheme seeks to provide an asymptotic tracking of speed and rotor flux in spite of the presence of an uncertain load torque and an unknown value of rotor resistance. The validity for practical implementation has been verified through computer simulations.     

感应电动机系统的变结构反推控制研究

感应电动机系统的矢量控制为了进行电流(或电压)的3/2(或2/3)坐标变换需要进行转子转差或磁链角的计算，转子转差的计算容易受转子电阻变化的影响，而磁链角的直接计算容易受定子电阻变化的影响，因此避免转子转差或磁链角的计算对于感应电动机系统的控制是非常有意义的。文中把变结构反推控制运用于感应电动机系统的转矩和磁链控制，设计方法避开了转子转差或转子磁链角的计算，通过一定的坐标变换，基于定子侧的静止坐标系实现转矩和磁链的解耦控制。变结构反推控制设计能够实现快速的速度、转矩和磁链的渐近跟踪，同时系统控制器能够保证系统性能在电动机参数和外部负载变化时具有强的鲁棒性，通过Matlab仿真验证了系统设计的有效性和可行性。     

Nonlinear adaptive state-feedback speed control of a voltage-fed induction motor with varying parameters

An adaptive nonlinear-state-feedback speed control scheme of a voltage-fed induction motor has been developed in which the control of torque and flux is decoupled. The inputs to the control algorithm are the reference speed, the reference flux, the measured stator currents, the measured rotor speed, the estimated rotor flux, and estimates of the rotor resistance, stator resistance, and load torque, which may vary during operation. The controller outputs are the reference stator voltages in rotor-flux rotating reference frame. An accurate knowledge of the rotor flux and machine parameters is the key factor in obtaining a high-performance and high-efficiency induction-motor drive. The rotor flux is estimated using the induction-motor rotor-circuit model. Although the estimated rotor flux is insensitive to the stator-resistance variation, it does depend on the rotor resistance. A stable model reference adaptive system (MRAS) rotor-resistance estimator insensitive to stator-resistance variation has been designed. Stable stator-resistance and load-torque MRAS estimators have also been developed. These estimators have been developed to constitute a multi-input-multi-output (MIMO) decoupled-cascade structure control system. This simplifies the design problem of the estimators for a stable operation from a MIMO design problem to a single-input-single-output (SISO) design problem. The continuous adaptive update of the machine parameters and load torque ensures accurate flux estimation and high-performance operation. Simulation and experimental results are presented to verify the stability of the induction-motor drive in various operating modes.     

负载转矩未知时变情形下异步电动机的无源性跟踪控制

应用无源性控制理论和方法,研究了在转子电阻确定已知,负载转矩和期望转矩任意时变的情形下异步电动机期望转矩的渐近跟踪控制问题.首先分析负载已知的情形,然后主要研究了负载转矩时变未知的情形,给出了此时负载转矩的实时估计方法和控制器设计方法.最后进行了仿真验证,证明这样设计的控制器性能良好.     

感应电机高性能鲁棒速度跟踪控制器设计

针对系统模型不确定性和干扰对矢量控制性能的影响,利用Q-参数化理论设计控制器,设计了一种简单有效的感应电机速度控制策略。该速度控制器由鲁棒转子磁链估计器(RRFE)以及参考模型跟踪控制器(RMTC)两个部分构成。RRFE主要用于转子磁链估计,以确保转子磁链获得快速准确的定向,而RMTC则在电机参数发生变化和出现干扰的情况下,获得磁链和转速的渐进跟踪性能。仿真试验结果表明,干扰得到有效抑制,系统具有较好调速性能。     

A nonlinear tracking control for sensorless induction motors with uncertain load torque

We propose a novel nonlinear tracking control algorithm for induction motors with uncertain load torque in which only stator currents are used for feedback: rotor speed and flux sensors are not required; no open‐loop integration of flux dynamics is used. For a class of reference signals, for sufficiently small computable time‐varying load torque uncertainty and for any initial condition belonging to an explicitly computed region, closed‐loop boundedness is guaranteed while, under persistency of excitation, local exponential rotor speed and flux modulus tracking are achieved in the case of constant load torque. Copyright © 2007 John Wiley & Sons, Ltd.     

具有效率优化计算的异步电动机自抗扰与滑模直接转矩控制

为了克服异步电动机直接转矩控制中转矩和电流脉动大等缺点,设计改进的自抗扰速度控制器取代传统的比例积分(PI)控制器。根据异步电动机的数学模型以及滑模变结构控制理论设计了一种基于转矩误差和磁链平方误差的新型滑模控制器。考虑电机运行过程中负载转矩未知问题,设计了一种基于Super-twisting算法的负载转矩观测器。Super-twisting定子磁链观测器的应用提高了观测精确度。通过效率优化计算得出稳态时最优定子磁链,并将其引入调速系统。仿真试验结果表明,该控制策略有效地减小了转矩和电流脉动,并且对外部扰动具有较强抑制作用,同时能够降低电机运行损耗,具有良好的动态和稳态性能。     

同步电动机任意设定转速的无源性跟踪控制

建立了同步电动机基于E-L(Euler-Lagrange)方程的无源性控制数学模型,基于此模型,针对任意时变且未知的负载转矩,对任意设定的期望转速,通过设计负载转矩估计器和期望轨迹设计器,给出了同步电动机无源性转速跟踪控制器的一般设计方法.这种控制器无需转子阻尼绕组电流观测器,无需磁场定向.仿真证明这种控制器能很好地实现期望的跟踪控制目标,具有较好的跟踪控制效果.     

Speed sensorless torque control of an IPMSM drive with online stator resistance estimation using reduced order EKF

Speed sensorless control of an interior permanent magnet synchronous motor (IPMSM) based on direct torque control (DTC) is proposed in this paper. The rotor speed and position of the IPMSM are estimated based on an active flux concept, where, the active flux vector position is identical to the rotor position. The proposed algorithm does not require neither high frequency injection signal nor complicated schemes even at vary low speed operation. Torque/ flux sliding mode controller (SMC) combined with space vector modulation is proposed to improve the performance of the classical DTC. Stator resistance value is required for a stator flux and electromagnetic torque estimation. Its variation due to temperature or frequency degrades the scheme performance, especially, at low speed operation. To overcome this problem, a reduced order extended Kalman filter (EKF) is proposed to update online the stator resistance. The advantages of the direct torque control, sliding mode controller, and speed sensorless control are incorporated in the proposed scheme. Simulation works are carried out to show the ability of the proposed scheme at different operating conditions. The results demonstrate the activity of the scheme at wide range speed operation with load disturbance and parameters variation.     

感应电机无源性分析及自适应控制

感应电机由于其变量非线性耦合、转子电量难以测量、电机参数时变性这3方面的问题，导致交流调速控制复杂。无源性控制理论应用于感应电机控制是一种全新的方法，其控制律是全局定义的，无输入输出线性化解耦奇点问题，是间接磁场定向控制。证明了感应电机转子磁链子系统的无源性，找到系统能量耗散特性方程中的无功力，它不会影响系统的稳定性，得出无需转子磁链观测反馈即能稳定跟踪转子磁链的参考值，同时考虑电机转子电阻在运行中发生未知变化，设计自适应调节器使系统对转子电阻呈现鲁棒性，构建了带电流内环速度控制系统。该方案保证转矩、转子磁链及转速的渐进跟踪，使调速系统具有良好的动静态性能，易于实现。仿真验证了设计的控制系统的有效性和先进性。