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.     

Bearingless motor’s radial suspension force control based on flux equivalent with virtual winding current analysis method

A bearingless motor has two sets of intercoupling stator windings, namely torque windings and sus-pension force windings. The decoupling control of the two sets is difficult and a key technology to stable operation for a bearingless motor. In this paper, a simple, reliable and accurate analysis method is put forward using the concept of flux equivalent with virtual winding currents. By this method, the suspension operation condition PB=PM±1 for bearingless motors is testified, and under the rotation conditi...     

Continuous on-line adaptation of the rotor time constant in FOC induction machine system

Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.     

Autonomous control of multi-fingered hand

This paper describes a novel autonomous control strategy of multi-fingered hand based on a modular control system of dexterous manipulation. A simple proportional-integral-derivative(PID) position control with friction compensation, which requires few friction parameters, is used to realize accurate and smooth trajectory tracking in pregrasp phase. In grasp and manipulation phases, an event-driven switcher is adopted to determine the switching between unconstrained position control and constrained torque control, and an improved explicit integral force control strategy is implemented to realize simultaneously stable contact transition and accurate force tracking. Experimental results have verified the effectiveness of the proposed autonomous control strategy of multi-fingered hand.     

Development and study on automatic balancer based on counter weight by magnetic force

Rotating machines are very sensitive to mass unbalance which has a harmful effect on its running accuracy and service life. Therefore,a variety of dynamic balancing methods and devices are studied to reduce the vibration caused by mass unbalance. On-line active balancing is a new balancing procedure which is more convenient and precise than the previous methods. In this paper,an electromagnetic balancer based on ring coils and permanent magnets is presented. The balancer has a simple structure and the self-locking function without clutch,and transfers power by the non-contact electromagnetic field. In order to justify the rationality of its design,a two-dimension(2D) electromagnetic finite element model is conducted to verify that this magnetic circuit has no flux leakage and saturation. A three-dimension (3D) 1/10 model of the balancer is built to obtain the self-locking torque and driving torque. Based on the research work above,an electromagnetic balancer is developed. By testing the balancer using COCO80,it is verified effective to reduce the rotor unbalance at the speed of 1300 r/min.     

A LOCAL CONTROLLER BASED CONSTANT TENSION CONTROL SYSTEM

This paper is mainly about a local controller whose main function is to achieve the constant tension of the thin denier filament in the high speed winding process. A mathematic model of the induction motor while controlling its stator frequency and voltage is given. A new kind of variable parameter, real time constant tension control system is presented. The paper uses the microprocessor -INTEL 8097 as the CPU of the local controller. A standard serial communication interface-RS232 is used to communicate with the main computer. Computer simulation and experiment test show that this system has good control characteristics.     

Study of engaged performance regulation in controlled transfer clutch of 4WD car based on genetic sliding mode control

This paper investigates an approach to improve the engagement quality of controlled transfer clutch mode in 4 wheel drive （WD） car from three considerations of reducing friction, smoothening responsiveness and alleviating jerk. The method utilizes an improved sliding mode control with genetic algorithm instead of simplified mode to determine appropriate values of parameters in control close-loop, The simulation results show that the method is effective for improving the engagement quality of coupling satisfying different design needs for 4WD car, as well as robustness even if input torque is changed at a certain range.     

Design and research of torque tube used in HTS motor

In order to improve the overall performance of high temperature superconducting （HTS） motor, a radial connection torque tube with high strength and low thermal leakage has been designed. Firstly, fiberglass epoxy composite is chosen as con- struction material. The structural size of the torque tube is obtained by means of load analysis and theoretical calculation. Secondly, thermal leakage of the torque tube is calculated with both theo- retical method and 3D finite-element analysis （FEA）. According to the result of the thermal analysis and mechanical loads, the struc- tural stresses of the torque tube are also obtained by FEA method. Lastly, a low temperature test platform is developed to verify the strength and the thermal leakage of the torque tube. The results show that the maximal shear stress of the torque tube is 24.3 MPa and thermal leakage of torque tube is 10.5 W, which satisfy the design requirements of the HTS motor. The torque tube also works in good condition at full-power and full-torque testing of the motor. The design method is also applicable for other similar design of torque tube in other applications.     

A cylindrical rod ultrasonic motor with 1 mm diameter and its application in endoscopic OCT

A tiny ultrasonic motor was constructed by using a piezoelectric ceramic cylindrical rod as a vibration generator of the stator. The fabricated tiny motor has a diameter of 1 mm, a length of 5 mm and a weight of 36 mg. The resonant frequency is 32 kHz with one fixed boundary or 83 kHz with two free boundaries. Four silver electrodes were deposited on the cylindrical surface. The spacing between two adjacent electrodes was carefully designed. A method was developed for the polarization of the stator. By using the bending vibration mode of the stator, the motor shows a performance with a speed of 1800 rpm and a stalled torque of 4μNm, and can bear a high driving voltage up to 350 Vpp. The motor was used to drive an optical prism for circular scanning in an endoscopic OCT system. The tomographic images of the inner cavities of a plastic tube and a scallion were obtained, and the resolution was of the order of micrometer-scale.     

Research on Precision Assembly Robot''''s Joint Torque Control Based on Current Measurement

A set of new current sensing device is used to realize joint torque control based on current measurement in a precision assembly robot's third joint. The output torque's model of the joint's brushless DC motor is founded. Disturbance factors and the compensated effect of the torque's closed loop based on current measurement are analyzed. Related simulations and experiments show that the system has good current tracking and anti-disturbances performance, which improve the force control performance of the robot in assembly.     

一种改进式无刷双馈电机三电平直接转矩控制算法

针对无刷双馈电机直接转矩控制算法转矩脉动和磁链脉动大的问题,基于固定合成矢量方法提出了一种改进式无刷双馈电机三电平直接转矩控制算法,增加了空间电压矢量的可选择性,使得磁链脉动和转矩脉动控制在较小的范围内.在Matlab/Simulink软件平台上搭建了无刷双馈电机三电平直接转矩控制算法模型,并对改进式三电平直接转矩算法进行了验证.实验结果表明,该算法有效地减小了磁链脉动和转矩脉动,获得了更好的磁链轨迹和转矩波形,电机转速更加稳定,同时保持直接转矩控制算法转矩响应速度快的优点,提高了控制系统的鲁棒性和动态性能.     

永磁同步电机模糊直接转矩控制仿真

针对永磁同步电机直接转矩控制中存在较大转矩脉动的缺点，提出用模糊控制器取代滞环比较器的控制策略．基于Simulink FIS工具箱对模糊直接转矩控制系统进行了仿真．结果表明：通过对转矩误差、定子磁链误差的模糊分级，结合转子位置得到适舍的电压控制矢量，能减小转矩脉动和磁链脉动；模糊直接转矩控制转速和转矩响应优于传统直接转矩控制．     

基于高频信号注入的无传感器新型DTC系统

针对传统的直接转矩控制方法中存在的转矩脉动大、开关频率不恒定等问题,在分析永磁同步电机定子磁链坐标系中电压和磁链方程的基础上,提出了一种新型的基于空间电压矢量调制的直接转矩控制方法,并采用注入高频信号的方法来估计电机的转速和位置。通过Matlab仿真软件建立了该控制方法的仿真模型。仿真结果表明,该控制方法能有效地减小电机的磁链和转矩脉动,高频信号注入法可以准确估计出电机的转速和位置,系统具有良好的动态和静态性能。     

永磁同步电机直接转矩控制新型占空比调制策略

针对传统永磁同步电机直接转矩控制系统转矩脉动和磁链脉动较大,现有占空比调制策略计算复杂等问题,提出一种新型占空比调制策略.该调制策略利用定子磁链和扇区电压矢量的作用角区分转矩脉动和磁链脉动在控制系统中的权重系数,并设计新型开关表,保证在任一控制周期中最佳电压矢量的选择.在保证系统计算量较低的前提下,利用权重系数和最佳电压矢量推导最优占空比计算公式.仿真和实验结果证明,所提出的新型占空比调制策略可以大幅度抑制转矩脉动和磁链脉动,获得较好的稳态运行性能,并保持系统快速动态响应性能.     

永磁同步电机直接转矩控制电压矢量选择区域

为了解决直接转矩控制系统开关表引起的转矩脉动问题,分析了电压矢量对永磁同步电机直接转矩控制系统的定子磁链幅值、转矩角、励磁转矩、磁阻转矩和电机转矩的作用,用简单的数学表达式给出了这些变量的控制规律,得出了永磁同步电机直接转矩控制系统的电压矢量选择区域。研究结果表明：电压矢量与定子磁链的夹角决定了电压矢量对定子磁链幅值和转矩角的增减作用;电压矢量与定子磁链的夹角和转矩角决定了电压矢量对励磁转矩和磁阻转矩的增减作用;电压矢量与定子磁链的夹角、转矩角和永磁同步电机直接转矩控制系统参数决定了电压矢量对转矩的增减作用。     

改善直接转矩控制性能的SVPWM方法

针对异步电动机直接转矩控制系统存在转矩和磁链脉动、器件开关频率不定等缺点,提出一种直接转矩空间矢量脉宽调制(SVPWM)预测控制方法。根据转矩和定子磁链的误差,通过驱使误差为零的原则确定参考电压矢量,然后利用SVPWM合成该矢量。由于采样时刻的电压和磁链误差,可在下一个控制周期内得到补偿,因此转矩和磁链的误差始终很小,二者的脉动很小。SVPWM算法保证了逆变器的开关频率恒定。仿真和实验的结果表明,利用这种方法在低于3kHz的恒定开关频率下,可以实现定子磁链近似为圆、异步电机电磁转矩脉动不明显的性能。     

直接转矩模糊控制感应电动机驱动系统的研究

直接转矩控制是一种新型的感应电动机控制方法,设计的关键是怎样选择适当的定子电压矢量来使定子磁链和转矩限制在它们的允许范围内.然而由于滞环控制器的特点,不论转矩偏差的大小均采取同样的开关策略,因此,在起动或给定转矩、给定定子磁链发生阶跃变化时的响应较缓慢和产生大的转矩脉动.用模糊控制器可以解决这个问题.仿真结果证明此方案可行.     

基于神经网络与模糊逻辑的直接转矩控制系统

实现直接转矩控制 (DTC)的关键部件是定子磁链观测器和逆变器状态开关选择器 ,用训练好的神经网络取代U I N模型 ,模拟传统异步电动机DTC系统定子磁链观测器 ;把模糊控制算法引入状态开关选择器 ,用较少的模糊规则实现磁链误差、转矩误差和磁链角对逆变器开关的分级控制 .仿真结果表明 ,基于神经网络与模糊逻辑控制方法建立的直接转矩控制系统 ,具有较强的鲁棒性和良好的动态性能     

基于零矢量插入的矢量细分的PMSM直接转矩控制研究

依据永磁同步电机直接转矩控制理论,采用矢量细分的控制策略和SVPWM调制方法,将原6个电压矢量和6个磁链扇区细分成12个电压矢量和12个磁链扇区,并分析不同电压矢量在每个定子磁链扇区内对转矩的作用,在此基础上,引入零矢量的插入,提出新的电压矢量开关表,利用MATLAB软件进行仿真,理论分析和仿真结果表明这种控制策略可以在很大程度上减小转矩脉动,具有更好的动静态性能.     

DTC 技术开关表建立方法研究

在传统的矢量控制技术蓬勃发展起来以后,直接转矩控制技术（DTC）横空出世,它适用于高性能异步电动机变频调速系统。其方法是首先选择合适的定子电压空间矢量,其次使定子磁链的运动轨迹近似为圆形或是多边形,最终达到电磁转矩和磁链模值的跟踪控制的目的。以开关磁阻电机为例分析了直接转矩控制系统开关表的建立方法。