异步电机无速度传感器矢量控制系统的研究

为了实时辨识电动机的转子转速,提出利用在异步电机端测量得到的电压和电流来估算电机转速,以实现无速度传感器矢量控制的模型参考自适应方法.在MATLAB/Simulink中,建立了一个基于该方法的无速度传感器矢量控制系统,并进行了仿真实验,仿真结果表明该系统具有良好的动静态特性和稳定性.     

Rotor resistance adaptation for sensorless vector-controlled induction machines

The vector control method is widely used for induction motor drives. In these applications, a rotational transducer such as a shaft encoder is used. A rotational transducer, however, cannot be mounted in some cases, such as motor drives in a hostile environment or high-speed motor drives. Several sensorless vector-controlled induction machine drive methods have been proposed. These methods have the disadvantage that rotor resistance variation causes errors in the estimation of the motor speed. It is difficult to estimate the motor speed and the rotor resistance simultaneously, because the equivalent rotor resistance is the ratio of the rotor resistance to the slip at steady state. Therefore, we have proposed a method of simultaneously estimating the motor speed and the rotor resistance of an induction motor by superimposing ac components on the field current command. This paper presents a modified method of the rotor resistance adaptation. The validity of the proposed method is verified by experiments. © 1998 Scripta Technica, Electr Eng Jpn, 125(2): 65–72, 1998     

异步电动机无速度传感器的矢量控制

对交流异步电动机无速度传感器的矢量控制进行了综述 ,分析了几种控制方案的原理 ,指出了它们各自的优点与不足 ,并就今后的研究发展方向提出了一些设想     

感应电机无速度传感器控制自适应速度观测器

理论与实践证明自适应速度观测器是实现高性能的感应电动机无速度传感器控制系统的有效方法之一。由于该系统的非线性性质,在观测器设计以及系统应用中还有许多有待解决的问题。针对此类问题,从理论联系实际的角度,分析现有的电机磁链、速度观测器理论的要点及其成果,如建模的条件、自适应速度估计算法及其物理性质、系统稳定性分析、线性化方法、以及观测器参数的辨识等。同时,给出了实验结果、指出了这些内容中尚存的相关问题。     

无速度传感器异步电机矢量控制系统的改进研究与仿真

以异步电机矢量控制的基本方程式为基础,构建了一个无速度传感器矢量控制系统。系统采用了改进积分型转子磁链估算模型。根据模型参考自适应方法的原理,提出一种改进的速度估算法。并利用MATLAB/SIMULINK进行了仿真,仿真结果验证了采用的速度估算方法是正确的。     

Design of an adaptive observer for sensorless vector control of induction machines under regenerating conditions

The objective of this investigation is to stabilize a sensorless vector control system of induction motors by means of an adaptive observer in regenerating mode at very low speed. The adaptive observer gain is designed by means of the Routh–Hurwitz criterion. It is verified by simulation and experiment that the proposed system is stable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 78–87, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10202     

Experimental verification for stability improvement of sensorless vector control system of induction motor using real‐time tuning of observer gain

This paper proposes a method for the design of the adaptive rotor flux observer gain to improve stability at low speed and in regenerating mode. The method is based on stability analysis, which utilizes a linearized model considering all systems, including each control loop. Therefore, the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for the rotor speed considers the arrangement of poles and zeros and the steady‐state error. The rotor flux observer gain which improves the stability for each operating condition is ascertained. This paper also proposes a real‐time tuning method for the observer gain. The validity of the proposed method was confirmed by simulation using Matlab Simulink and by experiment. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 67–81, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20715     

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。     

基于转速动态估计器的无速度传感器感应电机矢量控制系统研究

介绍了一种直接转子磁场定向无速度传感器的感应电机矢量控制系统。该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 ,有三个PI控制器分别控制转速、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 ,该系统具有较好观测精度和鲁棒性 ,动态和稳态性能也较好     

Sensorless vector control of induction motor stabilized in the whole region with speed and stator resistance identification based on augmented error

This paper proposes new identification laws of an adaptive flux observer for speed sensorless vector controls. In speed sensorless vector controls of an induction motor with the adaptive observer, the speed identification system is known to be unstable in a part of the regenerating region. In addition, it is pointed out that the stator resistance variation interferes with the speed identification. Thus, it is necessary to find an adaptive scheme which can stabilize the identification system. In this paper, first, the stability on the parameter identification is discussed from the viewpoint of Popov's hyperstability. Second, identification laws for the speed and the stator resistance are proposed based on the new identification system which is derived by using the augmented error. Finally, the effectiveness of the proposed method is shown by experiments. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(1): 52–63, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20187     

Application of induction motor speed sensorless vector control to railway vehicle traction

Pulse generators (PGs) are equipped to detect the rotor frequency of induction traction motors for torque control in railway vehicle traction field. Eliminating PGs is preferable from the viewpoints of increasing the reliability of the traction system, reduction of both the initial and maintenance cost, and downsizing induction traction motors. Expecting those advantages, we have been studying the application of a sensorless control method to induction traction motor control. Prior to some reports of studies and tests to apply speed sensorless strategy to railway vehicle traction we launched ideas to apply the speed sensorless control strategy and results of the studies and tests. In this paper, we present the novel control method for railway vehicle traction and some results of theoretical study and tests. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(2): 69–77, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20273     

MRAS-based speed sensorless control scheme with stator resistance identification function for vector-controlled induction motor drives

This paper describes a new scheme for the speed sensorless control of the vector-controlled induction motor drive. Based on the model reference adaptive system (MRAS) theory, the rotor speed of the induction machine is estimated with a full-order adaptive observer. The estimated speed then is used as the signal for the vector control and the speed control. To accurately estimate the speed at the lower speed range, the value of the stator resistance also is identified at the same time and then is used to modify the resistance value set in the observer. The resulting system is verified to be hyperstable with Popov's criterion. As a result, this drive can operate stably in a wide range of speed even at zero speed. Also, it is shown theoretically that neither speed nor resistance of the rotor can be identified at the same time because these two parameters are dependent on each other. Simulation results and experiments also show that the scheme is effective.     

异步电机无速度传感器矢量控制系统中扩展卡尔曼滤波器的优化研究

利用扩展卡尔曼滤波器,将转速看成一个状态量,根据定子的电流和电压值估算转速.通过仿真对滤波器初值的选取进行了研究,得到优化的卡尔曼滤波器,试验结果表明,速度估算的准确性高,系统对于电机参数的变化不敏感,具有较强的鲁棒性.     

一种高性能感应电机无速度传感器矢量控制策略

针对传统感应电机电压模型磁链估计算法存在积分初值问题与直流漂移问题,提出了一种改进型磁链估计算法,采用带通滤波器代替纯积分环节,并加入带有自适应磁链幅值估计器的补偿环节来补偿带通滤波器所引入的磁链幅值和相位误差。对该算法所需的各个参数的影响进行了深入研究,给出了参数的选择方法。结合一种简单实用的转速估计方法,提出了一种新型高性能感应电机无速度传感器矢量控制策略。仿真和实验结果表明,该控制策略动态和稳态性能良好,在宽调速范围内有效地解决了定子反电动势积分时存在的积分初值问题与直流漂移问题。     

一种异步电机无速度传感器间接磁场定向控制策略

针对无速度传感器异步电机,提出了一种新的滑模磁通和速度观测方法。实际电流和观测电流之间的误差收敛到零,保证磁通观测器的精确性。根据估计的定子电流和转子磁链来估计转子的转速和转子时间常数。估计的转子时间常数用于滑模计算和观测器结构中,估计的转速用来作为转速调节的反馈。仿真结果证明所提出的速度估算方法有效以及所提出的观测器结构具有鲁棒性。     

Usefulness of a frequency‐hybrid vector control for a sensorless induction motor drive

This paper examines and demonstrates the usefulness of a frequency‐hybrid vector control scheme for sensorless induction motor drive through actual‐machine‐based performance evaluation tests. The new approach utilizes a new indirect orientation scheme and a stable‐filter‐embedded direct orientation scheme, and exploits their advantages. It is confirmed through extensive tests with small and large standard motors such as 0.3, 3.7, 30 kW and special low‐voltage motors dedicated to electric vehicles that the sensorless vector control scheme has the following potential usefulness: (1) it can make machines that produce more than 200% rated torque at standstill, (2) in both motoring and regenerating modes, the rated torque can be produced even in the very slow speed range, including zero speed and zero frequency, (3) for constant speed, good linearity of torque response is attained, (4) it has the ability to track variable speed acceleration commands up to ±5000 rad/s² in the mechanical frequency sense, (5) it can accept a zero‐speed command and settles the machines to a stable standstill with no vibration, (6) it accepts instant injection of rated load even for zero‐speed control, and (7) it accommodates a load with huge inertia. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 44–58, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10073     

Compensation of stator iron loss of vector‐controlled induction motor using robust flux observer

A new vector control system of an induction motor is proposed in this paper to reduce the influence of iron loss, which has been difficult to deal with. Recently, many methods have been proposed to improve the accuracy of torque control, concentrating on the identification of parameters and the adjustment of the controllers. But, it is necessary for experts to tune parameters initially in those methods. The new method can reduce the influence of iron loss by using a robust flux observer. By adding current decoupling control for compensation of the iron loss, a vector control system with high torque linearity can be constructed. © 2001 Scripta Technica, Electr Eng Jpn, 137(3): 59–66, 2001     

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.     

A generalized method of controlled voltage source-fed induction motor vector control using the observer theory

Vector control of induction motors is widely used for industrial applications. On-line parameter identification and speed sensorless control are being studied actively. A representative method for these problems is the application of an adaptive full-order observer. The rotor flux for vector control is estimated by a full-order observer and machine parameters, or the rotor speed is determined by an adaptive algorithm. In this paper, a new vector control scheme with parameter identification is proposed. This method is based on the adaptive full-order observer. However, the observed currents which are usually estimated in the voltage model are considered as command currents and the voltage model is used for the current controller. As a result, the proposed system is simpler than the conventional adaptive full-order observer system. Since the proposed system is composed of an induction motor model in a synchronously rotating reference frame, the well-known slip frequency control block is contained. The arrangement of the poles which are related to the torque transfer function is discussed. A linear model is derived taking into account the effects of the change of the stator and rotor resistances. The trajectories of poles and zeros of the torque transfer function are computed and discussed for various system parameters. Identification of stator and rotor resistances is confirmed by simulation using a nonlinear system model. The proposed idea is applied to a speed sensorless system; this system has a similar configuration to those of existing systems under some assumptions. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(4): 66–76, 1997     

具有参数自适应特性的并网变流器无交流电压传感器控制方法

针对当前无交流电压传感器控制技术中存在的电压观测器适用性问题,研究了一种基于参数自适应电压观测器的无交流电压传感器控制方法。阐述了基于二阶广义积分器构造的电压观测器原理,提出利用锁相环在线实时反馈电网频率信号的频率自适应控制方法。在此基础上,利用简化模型分析电感参数偏离实际值情况下的向量关系,提出一种具有电感参数自适应特性的改进电压观测器。应用所提的改进控制方法,可实现频率和电感参数自适应的并网变流器无交流电压传感器控制,提高了并网变流器的电网适应性。