基于自适应观测器的无速度传感器感应电机控制

针对采用极点配置的自适应速度观测器存在不稳定区域的问题,建立了全阶自适应状态观测器并给出了观测器的速度辨识律.应用Lyapunov稳定性理论,观测器的增益借助于MATLAB LMI工具箱求解两个双线性矩阵不等式得到.在MATLAB 6.5/SIMULINK环境下,建立了无速度传感器感应电机直接转矩控制的仿真实验平台,给出了无速度传感器直接转矩控制的仿真结果.仿真结果表明本文给出的自适应观测器在全速范围内具有很好的稳态性能,并具有很好的鲁棒性.同时,在以TMS320F240为核心的感应电机直接转矩控制系统上进行了速度辨识实验,实验结果验证了方案的有效性.     

牵引电机无速度传感器的间接转矩控制的应用

分析了基于静止坐标系的间接转矩控制原理．在定子坐标系内分别对定子磁链与电机转矩进行计算并得到定子磁链增量值,包括定子磁链的幅值增量和相位增量,由定子磁链增量计算出异步电机定子的空间电压矢量．通过选择适当的定子磁链、转子磁链状态变量,构建一个感应电机的全阶闭环磁链观测器,实现转子转速的自适应辨识．实验结果表明,定子电流为正弦波且谐波小,电磁转矩的稳动态性能好,电机的辨识速度能够快速而准确地收敛到真实转速．     

基于PSO的全阶状态观测器转速辨识系统

对基于全阶状态观测器的异步电机矢量控制系统进行了研究与改进.通过对系统数学模型的深入分析,将改进的重心聚焦在全阶状态观测器反馈增益系数的优化上.以粒子群算法(Particle Swarm Optimization,PSO)作为优化手段,实现反馈增益系数的自寻优.在此基础上,论文通过对粒子速度更新公式的改进,使算法收敛速度明显提高.在Matlab/Simulink仿真环境下,进行了仿真验证.结果表明,基于改进型粒子群算法全阶状态观测器的异步电机矢量控制系统具有更加准确的转速估算精度与良好的运行性能.     

感应电机高阶终端滑模磁链观测器的研究

提出了基于高阶非奇异终端滑模的感应电机转子磁链观测方法,用于实现感应电机的按转子磁链定向控制. 设计了非奇异终端滑模面及观测器的控制策略,利用所设计的控制策略推导出电机转子磁链信息. 为了抑制常规滑模存在的抖振现象,设计了定子电流观测器的高阶滑模控制律,可将控制信号直接用于电机转子磁链的估计. 较常规滑模观测器,所提方法具有较高的观测精度,并对电机参数变化具有良好的鲁棒性.仿真结果验证了方法的有效性.     

一种用于感应电机的鲁棒变结构观测器

提出一种同时实现感应电机转速和转子电流观测的方法。针对感应机这一多变量耦合非线性时变对象,以Ｌｙａｐｕｎｏｖ稳定判据作为设计基础,通过变结构项的引入来抵消不可知部分,确保Ｌｙａｐｕｎｏｖ稳定判据的条件成立,从而得到原系统的鲁棒非线性观测器。理论分析表明,由于变结构项的引入,保证了所设计的观测器具有收敛性和对参数变动的鲁棒性。感应电机的仿真实验说明了该方法的可行性和良好性能。     

感应电机矢量控制系统的神经网络转速辨识

为解决感应电机无速度传感器矢量控制系统的转速辨识问题,在给定的无速度传感器感应电机间接矢量控制系统中,根据感应电机的数学模型,经过一定的变换,利用电机易于检测到的定子电压和电流,以及基于BP算法的两层神经网络,用期望状态与实际状态之间的偏差来调整神经网络模型的权值,达到实时辨识电机转速的目的。该方法简单、直观,不仅利用了神经网络的优点,又能适应感应电机调速系统实时控制的要求。仿真结果验证了该方法的有效性。     

感应电机无速度传感器直接转矩控制系统研究

直接转矩控制技术以容差形式的Bang-Bang控制模式给系统的稳态运行带来了转矩脉动大、电流谐波成分重、定子磁链轨迹畸变等严重问题,大大限制了其应用领域,这一点已经成为传统直接转矩控制技术不可逾越的缺陷。本文基于模型参考自适应系统（MRAS）原理设计了一种自适应速度磁链观测器,把磁链观测和速度辨识结合在一起,将定子磁链观测值直接应用于直接转矩控制算法。运用SIMULINK中的库元件和S-function构建了感应电机无速度传感器直接转矩控制系统仿真模型,仿真波形验证了上述控制模型可行性。     

一种新型的感应电机速度辨识策略

介绍了一种基于神经网络的感应电机速度估计策略。应用反向传播算法的神经网络实时辨识电机速度 ,其目标函数是目标模型和神经网络模型输出之间差的平方和。速度作为神经网络的一个权值 ,通过反向传播算法来调节使之精确地跟踪实际的电机速度。实验结果表明此方案是可行和有效的     

采用MRAS速度观测器的异步电机无电压传感器DTC研究

为提高系统的抗干扰能力,降低运行成本,提出无电压传感器控制策略,通过逆变器的导通状态和直流侧电压估算三相定子电压,采用模型参考自适应系统（ MRAS）方法设计速度观测器,基于异步电机数学模型得到转子磁链的两种模型,根据合适的自适应机构得到精确的实际转速,实时调节模型参数,该控制方法简单,保持较高的控制精度。最后通过实验验证了控制策略的可行性。     

基于重置算法的感应电机转速自适应观测器

常规并联双模型转速自适应观测器在电机启动、加速或突加负载时存在观测转速滞后性大、精度低的问题, 使得感应电机无速度传感器控制系统的调速性能变差. 针对上述问题, 提出一种重置自适应转速观测器对转子磁链进行观测, 同时通过自适应机构得到电机转速, 并利用Lyapunov 稳定性定理证明了系统的稳定性. 仿真和实验结果表明, 所提出的重置自适应观测器的观测误差小、稳定性好, 改善了在电机启动、加速或突加负载时的转速观测性能.

     

Adaptive interconnected observer for sensorless induction motor

An adaptive interconnected observer for induction motor (IM) drive without mechanical sensors (speed sensor and load torque sensor) is presented. The observer estimates the fluxes, the angular velocity, the load torque and the stator resistance even under or near unobservable conditions. Practical stability based on Lyapunov theory is proved to guarantee the strongly uniformly practical stability of the estimation error dynamics. A contribution of this article is the experimental validation of the observer on reference trajectories of a sensorless IM observer benchmark. The trajectories of this benchmark are chosen to test the motor near and under conditions of unobservability. Robustness with respect to parameters variations is proved and experimentally verified.     

Nonlinear speed observer for the PM stepper motor

A nonlinear observer for the permanent magnet (PM) stepper motor is considered. Specifically, the method of A.J. Krener and W. Respondek (1985) is used to construct a nontrivial full-order speed observer that has linear error dynamics. The procedure is validated by experimental results. Reduced-order observers are constructed by inspection     

Robust sensor faults detection for induction motor using observer

Current sensor is one of the key elements in the control system of induction motor.Whether the accurate measurement of variables reflecting motor operation status can be made will directly affect the control effect on motor system and therefore the timely,accurate detection of sensor fault is necessary.This paper brings forward an observerbased method of residual generation and fault detection on the basis of the mathematical model of the induction motor.As whether or not the nonlinear part satisfies the Lipschitz conditions does not limit the observer design,the application of such an observer is expanded.Meanwhile,the contradiction between robust error and fault sensitivity is also settled.The correctness and effectiveness of such method are verified by experimental testing on the simulated fault which also casts light on engineering practice.     

A new scheme for sensorless induction motor control drives operating in low speed region

A novel simple stator resistance estimation technique for high-performance induction motor drives is proposed. It makes use of a synchronously revolving reference frame aligned with the stator current vector, so that the resistance can be straightforwardly derived from the mathematical model of the induction motor. A sensorless direct field orientation scheme is employed to validate the proposed solution, with the drive operating in the critical area of low speeds. A combination of two observers is used: a Kalman filter observer to estimate the rotor flux, and a MRAS observer for speed estimation. The stator resistance estimator alleviates the usual performance degradation of MRAS-based drives at low speeds, caused by the thermal drift of stator resistance. Computer simulations, including realistic disturbances, show high effectiveness of the described approach.     

Hybrid control for speed sensorless induction motor drive

The dynamic response of a hybrid-controlled speed sensorless induction motor (IM) drive is introduced. First, an adaptive observation system, which comprises speed and flux observers, is derived on the basis of model reference adaptive system (MRAS) theory. The speed observation system is implemented using a digital signal processor (DSP) with a high sampling rate to make it possible to achieve good dynamics. Next, based on the principle of computed torque control, a computed torque controller using the estimated speed signal is developed. Moreover, to relax the requirement of the lumped uncertainty in the design of a computed torque controller, a recurrent fuzzy neural network (RFNN) uncertainty observer is utilized to adapt the lumped uncertainty online. Furthermore, based on Lyapunov stability a hybrid control system, which combines the computed torque controller, the RFNN uncertainty observer and a compensated controller, is proposed to control the rotor speed of the sensorless IM drive. The computed torque controller with RFNN uncertainty observer is the main tracking controller and the compensated controller is designed to compensate the minimum approximation error of the uncertainty observer instead of increasing the rules of the RFNN. Finally, the effectiveness of the proposed observation and control systems is verified by simulated and experimental results     

基于滑模与自适应观测器的感应电机非线性控制新策略

提出一种结合滑模变结构和自适应观测技术的感应电机非线性控制新方法. 以定子电流与定子磁链为状态变量建立感应电机模型, 采用非线性分析方法建立转矩与磁链误差方程, 使用自适应滑模技术设计转矩与磁链控制器, 推导出定子电压控制量. 基于模型参考技术设计自适应观测器, 向控制器提供准确的转速辨识与磁链观测值,并给出了控制系统的稳定性证明. 该方法具有转矩脉动小、定子磁链畸变不明显的优点, 低速时也具有良好的控制性能, 且对参数与负载变化有较强的鲁棒性. 仿真与实验结果证明了该控制策略的正确性与有效性.     

The intelligent integrated speed controller of DTC for induction motor

The parameters selection of proportional coefficient and integral coefficient (PI) for speed controller is important for direct torque control system. However, it is difficult to adjust these parameters. In this paper, firstly, we use particle swarm optimization to search the appropriate PI values of the speed controller. Secondly, based on the optimized PI parameters, the fuzzy-PI speed control strategy is presented to solve the poor self-adaptability problem. Thus, the proportional coefficient k _p and integral coefficient k _i can be adjusted dynamically to adapt to the speed variations. And finally, to obtain the high-speed parallel processing ability, the well-trained RBF neural network replaces the fuzzy-PI speed controller. The comparison with conventional PI speed controller shows that the proposed intelligent integrated speed controller brings good benefits of fast speed response and good stability and reduces the torque ripple. The validity of the proposed intelligent integrated speed controller is verified by the simulation results.     

感应电机二阶滑模次优算法定子磁链观测器设计

提出了基于二阶滑模次优算法的感应电机定子磁链观测方法,设计了定子磁链观测器,并应用到感应电机直接转矩控制中.本文设计的磁链观测器,通过准确的跟踪电流及其变化率,从而实现对转子磁链的准确估算,然后利用转子磁链与定子磁链的关系,估算出定子磁链.由于本文设计的定子磁链观测器是一个多输入多输出(MIMO)系统,稳定性分析非常复杂,为此将磁链估算误差的微分看作扰动处理,从而将MIMO的观测器模型分解成两个独立的单输入单输出(SISO)系统,简化了稳定性分析.将该观测器用于感应电机直接转矩控制中,达到了很好的控制效果.仿真和实验验证了该方法的有效性.