实时ADI仿真下感应电机全阶观测器的研究

针对当前无速度传感器的控制方法中,存在低频时无法稳定运行、转速估算不精准、计算量偏大等问题,利用鲁棒性控制理论、线性矩阵不等式(LMI)来选择观测器的增益,推导了符合稳定性与收敛性要求的自适应律。并在此基础上,优化设计了转子速度和定子电阻能同时观测的自适应全阶磁链观测器,以此来对转子速度进行准确估算,确保电机在全速范围内稳定运行。用MATLAB对自适应全阶磁链观测器进行模型仿真,最后以实时ADI半实物仿真试验系统验证了在实际运用中自适应全阶磁链观测器的设计在全速范围内准确估算转速的可行性,且有良好的抗负载扰动能力。     

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。     

基于MRAS的异步电机无速度传感器的矢量控制

由于电机定转子参数的变化,利用一般的转子磁链对转速进行估算,将导致不能得到准确的结果。这里采用积分型转子磁链的参考和可调模型构建出一个基于MRAS的异步电机无速度传感器的矢量控制模型。该模型提高了矢量控制系统的动态性能并利用MATLAB,sIMULINK进行了异步电机无速度传感器矢量控制系统的仿真,验证了文中所采用的模型参考自适应的速度估算方法的可行性以及对参数误差的鲁棒性。     

无速度传感器异步电机矢量控制研究

本文以异步电动机矢量控制原理为基础,研究基于MRAS的无速度传感器矢量控制系统。介绍一种改进型电压模型转子磁链观测方案,采用Matlab/Simulink软件进行了仿真实验。实验结果证明该方法能够较准确地估算转子磁链和转速,系统运行良好。     

转差频率矢量控制的电机调速系统设计与研究

鉴于直接转子磁场定向矢量控制系统较为复杂、磁链反馈信号不易获取等缺点,而转差频率矢量控制方法是按转子磁链定向的间接矢量控制系统,不需要进行磁通检测和坐标变换,并具有控制简单、控制精度高、具有良好的动、静态性能等特点。在分析其控制原理的基础上,应用Matlab／Simulink软件构建了转差频率矢量控制的异步电机调速系统仿真模型,并通过各模块间的参数配合调节与优化,对其进行了仿真分析。仿真结果验证了,采用转差频率矢量控制的调速系统具有良好的控制性能。     

基于滑模控制的异步电机无速度传感器DTC研究

建立了一种滑模速度观测器,用于电机转速的精确观测。该观测器充分利用电机状态方程具有的结构特点,设计出简单有效的速度估算方法,在转子磁链的估算中无须用到转子时间常数和转速等信息,提高了观测器对于参数误差的鲁棒性。将所建立的观测器和空间电压矢量脉宽调制技术(SVPWM)结合对电机进行控制,进一步提高了系统的调速性能。仿真结果验证了基于滑模控制理论的异步电机无速度传感器直接转矩控制系统的可行性以及对参数误差的鲁棒性。     

基于MATLAB/Simulink的异步电机控制系统建模与仿真

本文在基于转子磁链定向的异步电机矢量控制理论基础上,针对磁链闭环的矢量控制系统中转子磁链易受电机参数影响的不足,提出了转子磁链开环的矢量控制方案。利用模块化思想,在MATLAB/Simulink建立磁链开环的矢量控制系统的各个功能模块,然后对各个功能模块进行有机的整合,构成矢量控制系统的仿真模型;仿真结果表明该系统具有良好的动态性能和抗干扰能力,进而验证了该控制系统设计的可行性和有效性,为实际电机控制系统的设计和调试奠定了理论基础。     

基于EKF的异步电机直接转矩控制系统仿真研究

为了提高直接转矩控制(DTC)系统定子磁链估计精度,降低电流、电压测量的随机误差,提出了一种基于扩展卡尔曼滤波(EKF)实现异步电机转子位置和速度估计的方法.扩展卡尔曼滤波器是建立在基于旋转坐标系下由定子电流、电压、转子转速和其它电机参量所构成的电机模型上,将定子电流、定子磁链、转速和转子角位置作为状态变量,定子电压为输入变量,定子电流为输出变量,通过对磁链和转速的闭环控制提高定子磁链的估计精度,实现了异步电机的无速度传感器直接转矩控制策略,仿真结果验证了该方法的可行性,提高了直接转矩的控制性能.     

基于THS320F2812的开关磁阻电机磁链特性检测

本文研究了开关磁阻电机（SRM）磁链特性实验检测方法,建立了基于DSP芯片TMS320F2812的SRM磁链检测系统,利用ADC模块实时采集不同转子位置的电压、电流信号,将数据传送到上位机,根据间接磁链测量原理,由数字离散方法计算磁链值,得到SRM磁链电流特性曲线和磁链-转子位置-电流模型。     

基于Matlab/Simulink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STC12C5A60S2的帆板控制系统设计

以STC12C5A60S2单片机为控制核心,利用单片机控制风扇完成对帆板转角的控制。该系统主要模块有单片机控制模块,人机交互模块、角度检测模块、风扇控制调速模块、电源模块、声光报警模块。由角度传感器测得帆板角度并反馈给单片机风扇转速控制模块构成风速闭环控制系统,利用单片机产生的PWM控制风扇电机驱动模块,从而实现角度的精准控制。     

High-performance induction motor speed control using exact feedback linearization with state and state derivative feedback

This paper presents a novel nonlinear speed/position control strategy for the induction motor utilizing exact feedback linearization with state and state derivative feedback. The speed/position and flux control loops utilize nonlinear feedback which eliminates the need for tuning, while ordinary proportional-integral controllers are used to control the stator currents. The control scheme is derived in rotor field coordinates and employs an appropriate estimator for the estimation of the rotor flux angle, flux magnitude, and their derivatives. The overall control scheme can be easily implemented with a microprocessor-based control platform. An error sensitivity analysis is included which proves the system to be robust to parameter variation and even more, immune to rotor resistance variation. Simulation and experimental results validate the theoretical part of the paper and reveal the high performance and advantages of the novel control scheme.     

基于混合磁链模型的电励磁同步电动机矢量控制研究

电励磁同步电动机具有效率高且转动惯量小、功率因数可调等优点,广泛应用于大功率传动领域中。矢量控制技术得以有效实现的基础在于电动机磁链信息的准确获取,针对传统磁链观测器所存在的磁链轨迹非圆形以及不适合电机低高速运行等问题,分析了适用于全速范围的混合磁链观测器,并对其进行了理论分析,阐明了电流与改进电压模型之间的平滑切换机...     

Steady-state and transient performance evaluation of a DTC schemein the low speed range

In this paper, a direct flux and torque control scheme for industrial application is analyzed in order to emphasis the drive performance at standstill and in the low speed range. The control strategy utilizes the torque and rotor flux commands to determine the reference value of the stator flux. In order to improve the low speed performance a closed loop estimator is employed to evaluate the rotor flux. The validity of the control scheme is verified by simulations and experimental tests of an induction motor drive system     

Experimental evaluation of a rotor flux oriented control algorithmfor brushless doubly-fed machines

The brushless doubly-fed machine (BDFM) has shown potential for adjustable speed drive applications. Although the BDFM is readily applicable for industrial drives requiring only slow speed response, control methods for higher performance operation need to be explored. With the help of a suitable synchronous reference frame dq model, this paper defines a BDFM synchronous angle and employs an electric torque estimator to establish a rotor flux oriented control algorithm. Experimental results show the effectiveness of the proposed controller     

Robust decoupled control of direct field-oriented induction motor drive

This paper focuses on the development of a decoupling mechanism and a speed control scheme based on total sliding-mode control (TSMC) theory for a direct rotor field-oriented (DRFO) induction motor (IM). First, a robust decoupling mechanism including an adaptive flux observer and a sliding-mode current estimator is investigated to decouple the complicated flux and torque dynamics of an IM. The acquired flux angle is utilized for the DRFO object such that the dynamic behavior of the IM is like that of a separately excited dc motor. However, the control performance of the IM is still influenced seriously by the system uncertainties including electrical and mechanical parameter variation, external load disturbance, nonideal field-oriented transient responses, and unmodeled dynamics in practical applications. In order to enhance the robustness of the DRFO IM drive for high-performance applications, a TSMC scheme is constructed without the reaching phase in conventional sliding-mode control (CSMC). The control strategy is derived in the sense of Lyapunov stability theorem such that the stable tracking performance can be ensured under the occurrence of system uncertainties. In addition, numerical simulations as well as experimental results are provided to validate the effectiveness of the developed methodologies in comparison with a model reference adaptive system flux observer and a CSMC system.     

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.     

A sensorless vector control system for induction motors usingq-axis flux with stator resistance identification

This paper presents a sensorless vector control system for general-purpose induction motors, which is based on the observer theory and the adaptive control theories. The proposed system includes a rotor speed estimator using a q-axis flux and stator resistance identifier using the d-axis flux. The advantages of the proposed system are simplicity and avoidance of problems caused by using only a voltage model. Since the mathematical model of this system is constructed in a synchronously rotating reference frame, a linear model is easily derived for analyzing the system stability, including the influence of the observer gain, motor operating state, and parameter variations. In order to obtain stable low-speed operation and speed control accuracy, an algorithm for compensating for the deadtime of the inverter and correcting the nonideal features of an insulated gate bipolar transistor was developed. The effectiveness of the proposed system has been verified by digital simulation and experimentation     

A speed estimator for high performance sensorless control ofinduction motors in the field weakening region

The paper proposes a modified version of the model reference adaptive system (MRAS) based speed estimator, whose outputs of the reference and the adjustable model are rotor flux space vectors. The estimator is modified in such a way that the variation in the instantaneous level of the main flux saturation during operation in the field weakening is recognized and properly compensated at all times. The speed estimation scheme is equally applicable to both vector controlled and direct torque controlled induction machines, since it operates in the stationary reference frame and requires measurement of only stator voltages and currents. Verification of the proposed scheme is provided by simulation and by experimentation on an indirect feedforward rotor flux oriented induction machine for speed references of up to twice the base speed