基于神经网络的现代感应电机自适应L2鲁棒控制

提出一种用于现代感应电机调速的自适应L2鲁棒控制方法。采用反步法(backstepping)推导出2个自适应L2鲁棒控制器，这2个控制器1个控制转速和磁链外环，1个控制定子电流内环。考虑了由感应电机定转子电阻、转动惯量和负载转矩的不确定性造成的扰动，采用RBF(radial basis function)神经网络来补偿这些扰动。提出的控制器可以和1个转子磁链观测器联用。应用转子磁链定向模型固有的解耦性质和HJI(Hamilton-Jaccobi-Issacs)不等式，从全局上证明了控制系统的鲁棒性。仿真结果表明，提出的控制方法对感应电机的不确定性有很强的鲁棒性，且具有很高的动态性能。     

Direct torque control of sensorless induction motor drives: a sliding-mode approach

Direct torque control (DTC) is known to produce fast response and robust control in ac adjustable-speed drives. However, in the steady-state operation, notable torque, flux, and current pulsations occur. A new, direct torque and flux control strategy based on variable-structure control and space-vector pulsewidth modulation is proposed for induction motor sensorless drives. The DTC transient merits and robustness are preserved and the steady-state behavior is improved by reducing the torque and flux pulsations. A sliding-mode observer using a dual reference frame motor model is introduced and tested. Simulations and comparative experimental results with the proposed control scheme, versus classic DTC, are presented. Very-low-speed sensorless operation (3 r/min) is demonstrated.     

一种基于空间矢量调制的永磁同步电动机新型直接转矩控制方案

针对永磁同步电动机(PMSM)的传统直接转矩控制(DTC)中存在的磁链转矩脉动大和开关频率不恒定等问题,分析了直接转矩控制中影响磁链和转矩增量大小的因素,在建立定子磁链坐标系下永磁同步电动机数学模型的基础上,提出了一种基于空间矢量调制(SVM)的新型DTC方法,该方法利用定子电压在定子磁链坐标轴上的分量控制电动机的磁链和转矩,再结合空间矢量调制方法控制逆变器运行。仿真和实验结果证明了这种基于空间矢量调制的直接转矩控制方法可以有效地减小传统直接转矩控制中的磁链和转矩脉动,并使逆变器工作在恒定的开关频率下。     

Hardware Implementation of Direct Load Angle Controlled Induction Motor Drive

In this article, a direct load angle (DLA) control method for induction motor drive is proposed to reduce the torque and flux ripple. It is based on control of incremental change in load angle. The torque control is achieved without losing the benefits of conventional direct torque control (DTC) by reference stator flux angle, which is the sum of load angle and rotor flux angle. In this proposed DTC scheme, coordinate transformation is not required in torque control unit and reference voltage sector number and angle are not required in PWM unit, which reduces the control complexity. Proposed DTC control method is applied to two level voltage source inverter fed induction motor drive and hardware results are presented. From the hardware results, it is found that the proposed DTC control scheme impressively reduces the torque and flux ripples when compared with conventional space vector modulation (SVM) DTC.     

异步电动机直接转矩控制转矩脉动最小化方法研究

在传统的异步电动机直接转矩控制中,低速运行时定子电流的低次谐波成分比较大,这导致电机在低速时存在较大的转矩脉动问题,针对此问题本文提出一种新的控制方法.在传统直接转矩控制的基础上,推导出异步电动机全速度磁链观测数学模型.为进一步提高转矩响应速度和减小转矩脉动,又在全速度磁链模型的基础上引入了模糊逻辑思想,提出了全速度模糊模型直接转矩控制.该模型把磁链相位角、磁链误差和转矩误差作为模糊变量,并对其进行合理的模糊分级,来优化电压空间矢量的选择.实验结果表明该方法不仅能够提高转矩响应速度,而且能够有效地解决转矩脉动问题,在全速度范围内具有较好的动静态性能.     

基于磁场定向的矩阵变换器驱动感应电机变结构直接转矩控制

提出一种新型的基于磁场定向的矩阵变换器驱动感应电机直接转矩控制方法,将滑模变结构控制策略引入矩阵变换器驱动感应电机直接转矩控制中,以代替传统方法中的转矩和磁链滞环比较器,并结合矩阵变换器空间矢量调制方法,实现矩阵变换器开关频率恒定。实验结果表明,通过使用转矩和定子磁链2个滑模变结构控制器并结合矩阵变换器直接空间矢量调制,既可以保留传统矩阵变换器驱动感应电机直接转矩控制转矩快速响应的特点,又可以保证开关频率恒定和减小转矩脉动,有效地改善了系统的动静态性能。     

基于空间矢量调制的直接转矩控制算法研究

针对传统的直接转矩控制由于采用滞环比较器对磁链和转矩进行直接控制,导致出现开关频率不恒定,磁链和转矩脉动大的问题,提出一种基于空间矢量调制的直接转矩控制方法.根据感应电机的数学模型,建立磁链、转矩双闭环PI控制回路.直接以磁链和转矩作为控制量,采用空间电压矢量调制策略.该方法具有矢量控制连续平滑和直接转矩控制快速响应的特性.仿真和实验结果表明,相对于传统的直接转矩控制,基于空间矢量调制的直接转矩控制方案的开关频率恒定,大大减小了转矩脉动,改善了电流和磁链波形,使系统具有良好的动、静态性能,验证了该方法的可行性和有效性.     

感应电动机定子磁链与转矩解耦自适应控制

基于非线性状态变换和状态反馈，提出了感应电动机定子磁链和转矩的精确解耦控制策略。并针对电动机运行过程中定子和转子电阻值随温度升高而发生变化，提出了自适应解耦控制律，确保了电阻估计误差的收敛以及定子磁链和转矩对各自参考值的渐近跟踪。通过理论分析证明了自适应反馈控制的收敛性和整个闭环系统的稳定性，最后数字仿真验证了系统的控制性能。     

Diagnosis of stator inter-turn short circuits in DTC induction motor drives

This paper addresses the subject of stator fault diagnosis in direct torque control (DTC) induction motor drives. The particularities of the behavior of a DTC drive, when in the presence of inter-turn short circuits, are exploited, thus allowing the proposal of two different approaches for the diagnosis of this type of fault. One of the proposed diagnostic techniques is the well known motor current spectrum analysis. It is demonstrated that in a DTC induction motor drive, with stator inter-turn short circuits, the action of the torque and flux controllers introduce a strong third harmonic in the motor supply currents, which can be used to detect this type of fault. The other diagnostic technique is based on the multiple reference frames theory, recently proposed by the authors for the diagnosis of stator faults in line-connected motors. Here, its use is exploited in the diagnosis of stator faults in DTC induction motor drives. Simulation and experimental results demonstrate the effectiveness of the two proposed techniques for the diagnosis of stator faults but emphasize the fact that the multiple reference frames technique is the preferred one when the residual asymmetries of the motor are not negligible.     

基于固定合成矢量的三电平异步电机直接转矩控制

针对传统的具有中点电位平衡功能的三电平固定合成矢量异步电机直接转矩控制(direct torque control, DTC)方法会引起较大的定子磁链和转矩纹波的缺点,该文改进固定合成矢量的合成方式,提出了适用于高性能三电平异步DTC系统的"24矢量"法和"24矢量+变调制比"法。从磁链、转矩控制性能的角度出发,分析了其对电机性能的改善。这两种方法物理概念清晰,结构简单,易于实现,同时还保留了传统固定合成矢量方法的优点。实验结果证明了控制方法的正确性和可行性。     

利用定子磁链检测器的异步电机直接转矩控制系统调速方案

直接转矩控制广泛应用于异步电机调速系统中,但其磁链模型中积分环节迟滞偏移较大,以致转矩和定子电流都含有很强的脉动分量。提出了三电平供电定子磁链全速检测的异步电机直接转矩控制系统调速方案,通过在定子磁链观测模型中加装高通滤波器和低通滤波器,实现对定子磁链和转矩的全速跟踪,有效地改善了异步电机直接转矩控制系统的低速运行状况,并通过仿真验证了方案的可行性和有效性。     

一种新型永磁同步电机直接转矩控制

由于采用传统的电压空间矢量开关表控制逆变器动作的永磁同步电机(Permanent Magnet Synchronous Motor,简称PMSM)直接转矩控制(Direct Torque Control, 简称DTC)存在着电流畸变、磁链和转矩脉动大的缺陷.为解决之,提出了一种新型的基于电压空间矢量(Voltage Space Vectors,简称VSV)和磁链扇区细分的PMSM DTC策略.实验结果表明,该策略克服了DTC中VSV选择开关表存在的缺陷;减小了磁链位置观测及磁链和转矩补偿误差;改善了电流正弦度;抑制了转矩和磁链脉动;提高了系统的稳态性能,同时仍保持了DTC固有的转矩响应速度快,对系统参数摄动、外干扰、测量误差等鲁棒性强的优点.     

无速度传感器直接转矩控制方案的设计和仿真

直接转矩控制是一种高性能的交流传动控制策略,无速度传感器控制的研究代表了直接转矩控制系统的一个发展方向.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无速度传感器直接转矩控制方案.该方案还能对转矩和磁链实现良好的控制功能.计算机仿真结果证明了方案的可行性.     

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。     

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.     

一种新型永磁同步电动机滑模变结构直接转矩控制系统

传统的转矩和磁链双滞环型永磁同步电动机直接转矩控制系统具有转矩脉动大、开关频率不恒定、运行噪音大等缺点。为此,基于滑模变结构理论及空间电压矢量调制技术,提出一种新型永磁同步电动机直接转矩控制策略。根据永磁同步电动机定子磁链定向坐标系中的数学模型及滑模变结构理论推导出定子磁链及转矩控制规律。实验结果显示新型直接转矩控制具有转矩动态响应迅速,稳态转矩脉动和磁链脉动低,电流波形光滑,驱动系统对参数变化不敏感。     

Very-low-speed variable-structure control of sensorless induction machine drives without signal injection

A sensorless induction machine drive is presented, in which the principles of variable-structure control and direct torque control (DTC) are combined to ensure high-performance operation in the steady state and under transient conditions. The drive employs a new torque and flux controller, the "linear and variable-structure control", which realizes accurate and robust control in a wide speed range. Conventional DTC transient merits are preserved, while the steady-state behavior is significantly improved. The full-order state observer is a sliding-mode one, which does not require the rotor speed adaptation and provides accurate state estimation in the entire speed range. The proposed scheme is a complete variable-structure solution that allows persistent sensorless operation of the drive at very low speeds, including zero and 3 r/min, with full load. Simulations and extensive experimental results confirm the robustness, accuracy, quickness, and low-chattering operation of the drive.     

基于固定合成矢量的高性能三电平异步电机直接转矩控制系统研究

针对具有中点电位平衡功能的电平异步电机直接转矩控制（DTC）方法会引起较大的定子磁链和转矩脉动的缺点,改进固定合成矢量的合成方式,提出了适用于高性能三电平异步DTC系统的“24矢量”法和“24矢量＋变调制比”法。从磁链、转矩控制性能的角度出发,分析了它对电机性能改善的贡献。这两种方法物理概念清晰、结构简单、易于实现,且保留了原同定合成矢量方法的优点。实验结果证明了控制方法的可行性。     

一种新型永磁同步电动机滑模变结构直接转矩控制系统

传统的转矩和磁链双滞环型永磁同步电动机直接转矩控制系统具有转矩脉动大、开关频率不恒定、运行噪音大等缺点.为此,论文基于滑模变结构理论及空间电压矢量调制技术,提出一种新型永磁同步电动机直接转矩控制策略.根据永磁同步电动机定子磁链定向坐标系中的数学模型及滑模变结构理论推导出定子磁链及转矩控制律.实验结果显示新型直接转矩控制...     

Induction motor drive based on the stator flux vector control

This paper presents a new torque control algorithm for induction motors, based on the stator flux vector control. For each sampling period, the value of the stator voltage is calculated to keep the stator flux equal to the reference vector, while the stator flux reference vector is calculated to keep the rotor flux amplitude constant at all operating conditions. An improved stator and rotor flux estimation algorithm is proposed, enabling robust and stable operation of the drive, even at low speeds. The induction motor torque is manipulated by variations of the flux angular velocity, enabling drive operation with fixed switching frequency and ripple-free torque in the steady state. The performance of the proposed algorithm is tested through various experimental runs, proving good behavior of the drive in both transient and steady-state operating conditions.