Robust direct torque and flux control of adjustable speed sensorless induction machine drive based on space vector modulation using a PI predictive controller

A Direct torque and flux control design for a sensorless induction motor, following a Lyapunov-based stator flux observer is presented. In this control scheme, the torque error signal and the amplitude of the stator flux reference vector are delivered to a PI predictive controller. The predictive controller also uses information on the amplitude and position of the actual stator flux vector and measured stator currents to determine the voltage command vector for space vector modulation inverter. In addition, a conventional PI speed controller is used to generate the torque reference signal. Using the fifth order model of the three-phase induction machines in a stationary two axes reference frame, a nonlinear stator flux observer is developed in order to estimate the rotor speed, rotor and stator resistances simultaneously. The stability of this observer is proved by Lyapunov theory. It is shown that if the persistancy of excitation condition is satisfied, the estimated quantities converge to their real values. The effectiveness of the proposed control scheme is verified by computer simulation and experimental results.     

感应电机空间矢量直接转矩控制系统的效率优化

提出了一种感应电机空间矢量直接转矩控制系统的效率最优控制方法。在定子磁链定向坐标系中,建立了计及铁芯损耗的感应电机数学模型。分析了电机损耗与转矩、转速和定子磁链的关系,推导出了不同运行工况条件下效率最优的定子磁链幅值表达式,实现了感应电机直接转矩变频调速系统的效率最优控制。实验结果表明,所提优化控制策略,在保持直接转矩控制快速动态响应特性的同时,可有效提高电机轻载时的运行效率。     

Design of a new adaptive sliding mode observer for sensorless induction motor drive

This paper proposes a new speed and flux estimation method which has the robustness against the variation of the electrical parameters of the motor and the superiority in the dynamic characteristics. In the proposed method, the stator currents and the rotor fluxes are observed on the stationary reference frame using the sliding mode concept. And the rotor speed is estimated using the current estimation errors and the observed rotor fluxes based on the Lyapunov stability theory. Also a design method of the observer gain using H₈ norm is proposed to minimize the effect of the speed estimation error on the rotor flux observation. The experimental results are shown to verify that the proposed method shows the excellent performances under the variations of motor resistance and inductance.     

无速度传感器直接转矩控制系统的MATLAB仿真

采用定子磁链u-n模型计算定子磁链,并在此基础上将模型参考自适应应用于直接转矩控制系统中,实现了系统的无速度传感器运行。针对3kW异步电动机,采用MATLAB/SIMULINK软件进行了仿真。仿真结果表明,该系统对电机定子磁链的观测精度高,速度运算较准确,在全速范围内能保持较高的性能。     

基于优化滑模观测器的无刷直流电机变结构直接转矩控制

本文提出一种由一个优化滑模观测器及一个变结构控制器组成的直接转矩控制系统,应用于永磁无刷直流电机。滑模观测器用来获取绕组反电动势,为减小系统抖振,引入连续光滑的反正切函数,并且证明了观测器的收敛条件及稳定性。然后以转速误差为基准建立滑模切换面,构造出变结构控制器,得到转矩控制的参考值。最终通过转矩误差并参考霍尔位置信号选择合适的空间电压矢量,完成直接转矩控制。该方案的控制效果能够不受制于电机参数变化及干扰影响,具有很强的鲁棒性。实验结果证明了该方案的正确性及有效性。     

一种新型无速度传感器直接转矩控制方案及其仿真研究

在直接转矩控制理论基础上 ,推导出一种基于定子磁链矢量增量来确定定子参考电压矢量的新型控制方案。该方案不仅可以实现无速度传感器的闭环控制 ,而且能够减小转矩和磁链脉动 ,具有良好的动静态性能。计算机仿真结果证明了方案的可行性     

Sliding mode approach applied to sensorless direct torque control of cage asynchronous motor via multi-level inverter

To improve the robustness and performance of the dynamic response of a cage asynchronous motor, a direct torque control (DTC) based on sliding mode control (SMC) is adopted to replace traditional proportional-integral (PI) and hysteresis comparators. The combination of the proposed strategy with sinusoidal pulse width modulation (SPWM) applied to a three-level neutral point clamped (NPC) inverter brings many advantages such as a reduction in harmonics, and precise and rapid tracking of the references. Simulations are performed for a three-level inverter with SM-DTC, a two-level inverter with SM-DTC and the three-level inverter with PI-DTC-SPWM. The results show that the SM-DTC method achieves better performance in terms of reference tracking, while adoption of the threelevel inverter topology can effectively reduce the ripples. Applying the SM-DTC to the three-level inverter presents the best solution for achieving efficient and robust control. In addition, the use of a sliding mode speed estimator eliminates the mechanical sensor and this increases the reliability of the system.     

基于DSP的新型无速度传感器直接转矩控制系统的研究

将磁链状态预测器应用于直接转矩控制系统中,取代了传统的积分器,同时与一种简单实用的速度估计器成功地结合在一起,实现了系统的无速度传感器运行状态,针对1.1kW异步电机,采用数字信号处理器DSP（TMS320C232）进行了数字化实现,仿真与实验结果表明,该系统对电机定子磁链的观测精度高,速度估算准确,尤其是在较低转速下仍能保持很高的性能。     

交流伺服系统的积分模糊滑模控制

针对交流伺服系统，提出一种积分模糊控制方法，把模数控制和滑模型控制有机结合起来，并且引入积分环节，使系统不仅具有很强的鲁棒性和良好的控制性能，而且完全消除了滑模控制的高频库动现象。仿真研究结果表明了这一方法的有效性。     

基于改进滑模观测器的SPMSM无位置传感器矢量控制系统

将用于预测永磁同步电机转子位置和转速的滑模观测器进行了改造,并构建了无位置传感器的矢量控制系统;并在此基础上提出了一种用于补偿转子位置角预测误差的改进方法。最后用Matlab仿真验证了算法的有效性,对结果进行了分析讨论。     

一种用于异步电机无速度传感器控制的自适应滑模观测器

针对异步电机无速度传感器中存在的对参数变化鲁棒性差的问题,研究了一种基于自适应滑模观测器的异步电机无速度传感器的矢量控制方案。自适应滑模观测器根据电机静止坐标系下的数学模型构造了转子磁链观测器,定子电流观测值与实际值的误差构成观测器的滑模面,在滑模运动下该观测器的观测值最终趋近于实际值,从而实现转子磁链的估计。电机转速由自适应方法估算得到,滑模观测器的稳定性可由李雅普诺夫稳定性证明。与其他方案相比,该方法的优点在于实现简单,对参数变化具有鲁棒性。仿真和实验对控制方案的正确性和可行性给出了验证,该观测器可以实现对转子磁链和转速的观测,且在负载扰动和给定转速变化的情况下该滑模观测器具有鲁棒性。     

基于PLL自适应滑模观测器的PMSM无传感器控制

针对传统滑模观测器无传感器控制方法反电动势基波中高频谐波含量高、抖振严重以及转子位置估计误差大等问题,提出了一种锁相环结构(PLL)自适应滑模观测器永磁同步电机无传感器控制方法。首先,在满足Lyapunov稳定性的前提下,推导并建立了反电动势的自适应律,通过构造自适应滑模观测器,使得反电动势观测误差迅速衰减;同时采用带有消除旋转影响环节的锁相环得到转子位置,消除了转速变化的影响,进一步提高了观测精度;最后,在一台2.9 kW表贴式永磁同步电机上进行了实验验证。实验结果表明,该方法有效地抑制了滑模抖振,降低了反电动势中的高频谐波,提高了转子位置的观测精度。     

永磁同步发电机的无传感器滑模辨识及控制

针对坐标旋转法永磁同步发电机无速度传感器控制中忽略定子电流微分项带来的估计偏差大等问题,提出基于旋转坐标系的自适应锁相环和滑模辨识方法.采用近似滑模控制对模型电机定子电流进行控制,使发电机和模型电机电流相等,从而获得两电机转子相位差的正弦和余弦分量.建立直驱式永磁同步电机无速度传感器辨识模型和自适应锁相环模型,并利用基于反步法的自适应锁相环进行速度和相位观测,在此基础上利用Lyapunov函数设计法设计控制器.采用近似滑模辨识使模型电机电流快速逼近原电机电流且到近似正弦的控制量,自适应数字锁相环相位收敛快,采用Lyapunov函数设计的控制器能保证系统收敛.仿真结果验证了该方法的可行性和有效性.     

两级滤波滑模观测器的永磁同步电机无位置传感器控制

实现永磁同步电机矢量控制的前提在于电机转速与转子位置信息的准确获取,为此设计了一款基于两级滤波的滑模观测器用来对电机的转子位置和速度进行估算。第一级滤波的输出反馈给电流观测器,第二级滤波的输出用来计算转子的位置,并采用分段线性补偿对位置估算误差进行补偿。给出了永磁同步电机无位置传感器控制系统方案,分别对滑模观测器的电流观测、反电势观测、位置和速度估算、负载扰动和动态过程进行了仿真分析,验证了该滑模观测器算法的可行性。搭建了控制系统实验平台,分别对启动过程、反电势观测、位置和速度估算以及变参数控制进行了实验研究,验证了该滑模观测器算法的正确性。仿真和实验结果表明:该滑模观测器能够快速和准确的跟踪电机转子的位置和速度,系统具有响应快、鲁棒性强的特点。     

Development of torque and flux ripple minimization algorithm for direct torque control of induction motor drive

Direct torque control (DTC) is known to produce quick and robust response in AC drives. However, during steady state, notable torque and flux ripple occur. They are reflected in speed estimation, speed response and also in increased noise. This paper proposes a new control algorithm, which provides decoupled control of the torque, and flux with constant inverter switching frequency and a minimum torque and flux ripple. Compared to the other DTC methods, this algorithm is much simpler and has less mathematical operations, and can be implemented on most existing digital drive controllers. Algorithm is based on imposing the flux vector spatial orientation and rotation speed, which defines the unique solution for reference stator voltage. This paper contributes (a) Calculation of stator flux vector, torque and flux increments (b) The position of new stator flux vector determination (c) Calculation of the stator reference voltage (d) comparison of errors of different control strategies. In this paper, computer simulations and experimental results have been discussed for the proposed algorithm.     

感应电机磁链和转矩的非奇异终端滑模控制

针对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的转矩脉动大、电流谐波成分重、定子磁链轨迹畸变等问题,将非奇异终端滑模控制应用到了转矩和磁链控制中.为了提高传统滑模控制的收敛性,分别独立设计了转矩控制器和磁链控制器的非奇异终端滑模平面.转矩控制器和磁链控制器由等效控制项和非线性切换项组成,非线性切换项中的符号函数sgn(S)通过积分作用削弱了控制量的抖振.仿真结果表明,非奇异终端滑模变结构直接转矩控制具有动态响应快、转矩波动和转速波动小、鲁棒性强、低抖振的特点.     

双滑模统一控制在交流伺服系统中的应用

针对强耦合数学模型的伺服系统抗干扰问题,提出了一种位置、电流双滑模统一设计的方法。这种方法可以采用控制电压向量的方法,使位置、速度、电流误差都以滑模规律自动衰减,并且电压向量的选择加入模糊控制,使控制柔化,减少了系统在滑模线附近的抖动现象,使系统鲁棒性好,响应速度快。通过Matlab6．5的仿真,验证了这种方法的可行性。     

Research on a direct torque control for an electrically excited synchronous motor drive with low ripple in flux and torque

The electrically excited synchronous motor (ESM) has typically small synchronous inductance values and quite low transient values because of the damper windings mounted on the rotor. Therefore, the torque and stator flux linkage ripples are high in the direct torque control (DTC) drive of the ESM with a torque and flux linkage hysteresis controller (basic DTC). A DTC scheme with space vector modulation (SVM) for the ESM was investigated in this paper. It is based on the compensation of the stator flux linkage vector error using the space vector modulation in order to decrease the torque and flux linkage ripples and produce fixed switching frequency under the principle that the torque is controlled by the torque angle in the ESM. Compared with the basic DTC, the results of the simulation and experiment show that the torque and flux linkage ripples are reduced, the maximum current value is decreased during the startup, and the current distortion is much smaller in the steady-state under the SVM-DTC. The field-weakening control is incorporated with the SVM-DTC successfully. __________ Translated from Proceedings of the Chinese Society for Electrical Engineering, 2006, 26(7): 152–157 [译自: 中国电机工程学报]     

永磁同步电机滑模调速控制及其实现

永磁同步电机（PMSM）的模型是一个多变量,非线性,强耦合的系统,而滑模变结构控制（SMC）具有快速响应,对参数变化及扰动不灵敏,算法简单,易于工程实现等优点,这为复杂工业控制问题提供了一种很好的解决途径。本文中的PMSM调速系统,以TMS320F2812为主控芯片,利用指数趋近律法下的滑模变结构控制器进行控制,给出了滑模控制器的位置式和增量式表达式。并将推导出的算法以增量式的形式编写进程序,作为调速系统的软件。最后通过MATLAB仿真和具体实验证明了该系统具有动态响应速度快,电磁转矩脉动小,稳定等众多优点,使系统具有更好的鲁棒性。     

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.