LOW COST IMPLEMENTATION OF SPEED SENSORLESS INDUCTION MOTOR CONTROL USING STATOR FLUX ORIENTATION

The control platform of the induction motor （IM） with low costs is developed by using DSP MC56F8013 with a good performance/price rtaio. The control algorithm for the speed sensorless IM is studied based on the stator flux orientation （SFO）. The algorithm structure is simple to be implemented and cannot be influenced by motor parameters, The improved stator flux estimation is used to compensate errors caused by the low pass filter （LPF）. A new speed regulator is designed to ensure the system working with the maximal torque in the transient state. The system simulation and the prototype experiment are made. Results show that the con- trol system has good dynamic and static performance.

Nonlinear Decoupling Control of the Bearingless Induction Motors Based on the Airgap Motor Flux Orientation

The bearingless induction motor, which combines the inductionmotor and magnetic bearing is a strongly coupled complicatednonlinear system; the decoupling control of the electromag- net toqueand readial levitation force is the base of the stable operation ofthe benaringless motor. In this paper, the air-gap motor fluxoriented vector control is proposed to realize the decoupling controlof this nonlinear system even in the transient case based on thelevitation principle. Simulations show the stable suspension and goodperformance of the proposed algorithm.

A study of EV induction motor controller based on rotor flux oriented control

Induction motor is a multi-parameter, non-linear and strong coupling system, which requires efficient control algorithms. In this paper, rotor flux oriented control （FOC） algorithm based on voltage source inverter-fed is deduced in detail, including stator voltage compensation, closed-loop PI parameters＇ calculation of torque and rotor flux. FOC＇ s Simulink model is setup to simulate torque and rotor flux＇s response. At last, the experimental results are shown.

Direct Torque Control System and Sensorless Technique of Permanent Magnet Synchronous Motor

The direct torque control theory has achieved great success in the control ofinduction motors. However, in the DTC drive system of Permanent Magnet Synchronous Machine (PMSM)proposed a few years ago, there are many basic theoretical problems that must be clarified. Thispaper describes an investigation about the effect of the zero voltage space vectors in the DTCsystem of PMSM and points out that if using the zero voltage space vectors rationally, not only canthe DTC system be driven successfully but also the torque ripple is reduced and the performance ofthe system is improved. This paper also studies the sensorless technique in the DTC system of PMSMand configures the DTC system of PMSM with sensorless technique including zero voltage spacevectors. Numerical simulations and experimental tests have proved the theory correct. In thecondition of sensor-less, the DTC system of PMSM is wide-rangely speed adjusting, and the ratio ofspeed adjustment is 1: 100.

Application of direct torque control to electric screw presses for speeding up torque response and reducing starting current

Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control （DTC） system for speeding up torque response and reducing the starting current of electric screw presses and its application to the J58K series of numerical control electric screw presses with a dual-motor drive. The DTC drive system encompasses speed control, torque reference control, and switching frequency control. Comparison of the DTC dual-AC induction motor drive with corresponding AC servo motor drive showed that for the J58K-315 electric screw press, the DTC drive system attains a higher maximum speed （786 r/min） within a shorter time （1.13 s） during a 250 nun stroke and undergoes smaller rise in temperature （42.0 ℃） in the motor after running for 2 h at a 12 min-1 strike frequency than the AC servo motor drive does （751 r/min within 1.19 s, and 50.6 ℃ rise）. Moreover, the DTC AC induction motor drive, with no need for a tachometer or position encoder to feed back the speed or position of the motor shaft, enjoys increased reliability in a strong-shock work environment.

Overview of Model Predictive Control for Induction Motor Drives

Model predictive control(MPC)has attracted widespread attention in both academic and industry communities due to its merits of intuitive concept,quick dynamic response,multi-variable control,ability to handle various nonlinear constraints,and so on.It is considered a powerful alternative to field oriented control(FOC)and direct torque control(DTC)in high performance AC motor drives.Compared to FOC,MPC eliminates the use of internal current control loops and modulation block,hence featuring very quick dynamic response.Compared to DTC,MPC uses a cost function rather than a heuristic switching table to select the best voltage vector,producing better steady state performance.In spite of the merits above,MPC also presents some drawbacks such as high computational burden,nontrivial weighting factor tuning,high sampling frequency,variable switching frequency,model/parameter dependence and relatively high steady ripples in torque and stator flux.This paper presents the state of the art of MPC in high performance induction motor(IM)drives,and in particular the progress on solving the drawbacks of conventional MPC.Finally,one of the improved MPC is compared to FOC to validate its superiority.It is shown that the improved MPC has great potential in the future high performance AC motor drives.

An Improved Stator Flux Observation Method of Permanent Magnet Synchronous Motor

The stator flux and electromagnetic torque observation is the basis of direct torque controlled permanent magnet synchronous motor( PMSM) drive system. However,the traditional stator flux observer based on voltage model is affected by integral initial values and integral drift,that based on current model is affected by the parameters of PMSM,so a new stator flux observation method is proposed based on an improved secondorder generalized integrator( SOGI). Compared to the stator flux observation method based on the conventional SOGI,the proposed method can not only overcome the influence of integral initial values and integral drift,but also completely eliminate the DC offset's influence. Therefore,the observation accuracy of stator flux is further improved. The simulation and experimental results both show that the proposed method has a higher stator flux and electromagnetic torque observation precision.

Fault-tolerant stator flux oriented decoupling control for dual three-phase permanent magnet motor without diagnosis and reconfiguration

In this paper,the fault-tolerant capability of the existing stator-flux-oriented decoupling control(SFOC)for the DTP-PM motor is investigated,and a simple fault-tolerant SFOC is further designed to enhance fault tolerance.Firstly,the mathematical model of the DTP-PM motor in the stator-flux-oriented rotating coordinate system is analyzed.An SFOC is proposed to guarantee healthy operation performance,considering torque,flux linkage,and harmonic currents.Secondly,the coupling relationship under open-phase conditions is assessed.The assessed result shows that the coupling relationship between the harmonic and fundamental components results in conflicts and poor post-fault operation.Thirdly,the proposed SFOC includes an automatic deactivation module to detect conflicts with a variable threshold.The conflicted harmonic current controllers can be excluded automatically.Hence,fault-tolerant control can be remedied without diagnosing the specific fault scenario,and excellent faulttolerant capability can be achieved.Finally,experiments on a DTP-PM motor are carried out to verify the feasibility and effectiveness of the proposed strategy.

基于虚拟方波注入的五相永磁同步电机开路故障下直接转矩控制

在传统直接转矩控制(DTC)中,参考磁链往往是一个固定值,这将导致五相永磁同步电机(PMSM)在正常及容错情况下运行时效率不高。为解决该问题,该文提出一种基于虚拟方波注入的DTC(VSWI-DTC)策略。首先,建立五相PMSM在正常和开路故障情况下的数学模型,在同步旋转坐标系中推导出恒定转矩下电流幅值与定子磁链幅值的关系。其次,设计最优定子磁链探测器。通过向定子磁链幅值中注入虚拟方波信号,根据电流幅值的变化情况补偿定子磁链幅值,在线探寻最优定子磁链幅值。最后,与无差拍DTC相结合,实现电机高效率DTC运行。实验结果表明,所提策略不但能保持DTC良好的动态性能,抑制开路故障引起的转矩脉动,而且提高了电机在正常和开路故障情况下的效率。

基于数字孪生技术的牵引电机低转矩脉动虚拟控制方法研究

针对牵引电机存在的高转矩脉动问题,研究了基于数字孪生技术的牵引电机低转矩脉动虚拟控制方法:设备层获取物理实体牵引电机运行数据后,经通信接口将数据传输至数据层存储;软件层调用数据层中的数据,采用Unity 3D软件完成牵引电机由物理实体到虚拟的数字孪生,构建牵引电机虚拟机三维模型,并通过显示层虚拟仿真平台展示虚拟模型及相关数据,操控者从虚拟仿真平台观察、分析虚拟模型及相关数据后,利用连续型定子磁链轨迹的控制方法,在牵引电机转速增加的情况下,通过连续转换定子磁链轨迹来降低牵引电机的转矩脉动,完成牵引电机的低转矩脉动虚拟控制。试验结果表明:构建的牵引电机虚拟机模型与物理机实体结构相同,仿真度较高,可利用以虚控实,降低牵引电机的转矩脉动,消除转矩失控的情况,保障牵引电机的安全运行。

基于定子反电势衰减暂态的感应电机转子时间常数辨识方法

感应电机转子磁链定向控制的动态性能十分依赖转子时间常数的准确性。针对感应电机断电过程中的定子绕组反电势衰减暂态现象,提出一种利用曲线拟合和差分进化算法进行转子时间常数辨识的方法,通过测量定子电压和电流即可完成辨识。在定子反电势衰减过程分析的基础上,推导了不同负载情况、零序分量以及变频供电条件对辨识过程的影响,并对比分析了所提出的两种辨识方法的特点和应用场景。最后以一台22 kW感应电动机为实验对象,开展了定子反电动势波形测量实验,获得了不同工况下的转子时间常数辨识结果。通过与电机参数设计值进行比较验证了定子反电势衰减模型及辨识结果的准确性。研究成果可为感应电机矢量控制中的转子磁链准确定向奠定基础。

A novel MTPA and flux weakening method of stator flux oriented control of PMSM

Permanent magnet synchronous motor(PMSM)has the advantages of high efficiency,high power density and high reliability.It has been widely used in electric vehicles,rail transit,industrial transmission and other fields.Compared with the traditional PMSM control strategy,the Indirect stator-quantities control(ISC)of low torque ripple induction motor has high dynamic response performance in the whole speed range,with high stability and strong security.However,due to the inherent characteristics of PMSM,there are still some difficulties in applying ISC strategy,such as solving the load angle corresponding to the current torque,realizing the maximum torque per ampere(MTPA)control and flux weakening control method in the stator field oriented control algorithm of PMSM.In this paper,theoretical analysis and discussion are carried out for the above difficulties,and an indirect stator vector control(ISC)method for PMSM is proposed.Finally,combined with the electric drive application platform of electric vehicle,the simulation and experimental results verify that the proposed ISC control strategy of PMSM also has good dynamic and steady-state performance in the whole speed range.

基于超螺旋算法的永磁同步电机变结构自抗扰控制设计与验证

针对永磁同步电机直接转矩控制(direct torque control,DTC)存在较大的磁链,转矩脉动以及在低速运行段控制效果不佳等问题,提出了基于超螺旋滑模(super-twisting sliding mode,STSM)的变结构自抗扰控制(active-disturbance rejection controller,ADRC)调速方法.首先,设计基于幅值、相位补偿与死区补偿的定子磁链观测器,以解决直流漂移、积分饱和与开关时延的问题.其次,将传统直接转矩控制系统中的磁链环和转矩环上的滞环控制器替换成超螺旋滑模控制器以减小磁链和转矩脉动问题.再次,将变结构的思想引入到扩张状态观测器(extended state observer,ESO)的设计中,在速度环上设计了一种变结构自抗扰控制器.最后,通过搭建调速系统实验平台,对PI+STSM、ADRC+STSM与所提的变结构ADRC+STSM 3种控制方法开展对比实验,结果表明所提出方法的有效性和优越性.

长电缆供电大功率感应电机定子电阻鲁棒磁链观测方法

在长电缆供电的感应电机驱动系统中,由于控制器与电机距离过远,通常采用无速度传感器的控制方式。长电缆增大了感应电机的定子侧阻抗,尤其是数量级地增大了等效定子电阻,使定子电阻的温漂对磁链观测的影响增大,降低了磁链观测器的性能。针对长电缆供电的感应电机驱动系统,提出了一种定子电阻强鲁棒的磁链观测方法。该方法对传统的混合模型磁链观测器进行改进,采用一种对定子电阻完全鲁棒的模型参考自适应速度观测器获知转速,同步使用电流模型计算转子磁链,并使用此磁链计算过程代替原有的电流模型。该磁链计算过程对定子电阻完全鲁棒,因而提高了观测器对定子电阻的鲁棒性。硬件在环测试结果验证了该方法的可行性和有效性。

感应电动机按定子磁场定向控制

在矢量控制和直接转矩控制的基础上 ,取长补短 ,提出一种新型的感应电动机按定子磁场定向控制的方法 ,采用定子电阻压降补偿和电流转矩分量的闭环控制 ,实现了定子磁链和电磁转矩的协调控制。实验结果表明 ,该方案完全可行 ,系统具有良好的静。

基于定子电流矢量定向的异步电机转子磁链估计器及其应用研究

异步电机矢量控制的关键问题在于精确地估计转子磁链。然而,传统的磁链估计器的精度会因定子或转子电阻的摄动而降低。文中提出了一种基于定子电流矢量定向的转子磁链估计器。该新型估计器不包含定转子电阻,可以避免电阻参数摄动对估计精度的影响。开环和闭环的仿真结果表明,该估计器具有相当高的精度,并且在定转子电阻大幅度摄动时,估计结果几乎不受影响,显示出比传统的磁链估计器更强的抗扰动能力。

改进的直接转矩控制在异步电动机中的应用

该文提出了一种改进的直接转矩控制方案并应用于异步电机控制系统中。其不仅结构简单,而且性能可与传统的磁场定向控制相媲美。一个简单的转矩控制器代替传统的三态磁滞比较器用来保持恒定的开关频率,一个稳态工作的简单补偿器用于补偿电压模型中定子磁链估计的数值和相位误差。试验和仿真结果表明,该文提出的补偿方案取得了良好的控制效果,其在保持直接转矩控制的传动结构更为简单的同时,还大大提高了整个控制系统的性能。

磁通切换永磁电机等效模型与控制策略分析

针对传统转子永磁型电机散热困难导致永磁体发生不可逆退磁、限制电机出力、减少功率密度等问题,提出了一种定子永磁型磁通切换永磁(FSPM)电机,并对该电机结构特点与等效模型进行了分析,比较了定子磁场定向控制(SFOC)、直接转矩控制(DTC)及基于空间矢量调制的直接转矩控制(SVM-DTC)三种控制方法在FSPM电机上的应用效果。运用dSPACE的实验平台,对基于SFOC的FSPM电机驱动系统进行了实验研究。仿真与实验结果表明,采用SFOC的FSPM电机转矩脉动小、电流正弦度好以及低速性能优越,更适合于低速驱动领域的应用。

基于气隙磁场定向的无轴承异步电机非线性解耦控制

无轴承异步电机是一个强耦合的非线性复杂系统 ,实现其电磁转矩和径向悬浮力之间的解耦控制是该电机稳定运行的前提。本文在研究电机磁悬浮机理的基础上 ,利用电枢绕组气隙磁场定向控制来实现两者之间的动态解耦控制。实验证明该控制算法不仅能实现电机稳定的悬浮 。

直接转矩控制中一种磁链估计新方法

将直接转矩控制 (DTC)与定子磁链定向矢量控制(SFOVC)相结合 ,利用DTC中电压矢量的空间位置角 ,推导出SFOVC中的磁链定向角 ,然后根据旋转坐标系中的d轴和q轴电流分量 ,建立定子磁链估计的数学模型。这样可使DTC中磁链的估计更简便易行也更精确。给出了一个 7.5kW交流电机DTC的实验结果 。