基于气隙转矩的电机转矩测试仪

采用基于气隙转矩的方法对电机的转矩值在线进行辨识,自行搭建了硬件系统和编写了测试软件,通过测试数据发现,电机转矩辨识算法具有较高的精度。     

基于S7-200的步进电机控制器设计

基于S7-200采用额定电流可调等角度恒力矩细分的方法设计了步进电机控制器。该控制器不但改善了步进电机在低速运行时振动大、噪声大的缺点,而且克服了步进电机在自然振荡频率附近运行时易产生共振、以及输出转矩随着步进电机的转速升高而下降的缺点,从而显著地提高了步进电机的性能,使步进电机运动平稳、运行速度快、噪音低,且控制精度高。     

圆筒式直线步进电机的电磁场分析

利用齿层比磁导的方法,对两相八极式混合励磁直线磁阻步进电机进行了数学建模,分析了电机的参数及特性;并利用Ansoft公司的Maxwell软件对电机的特性进行了仿真;结果表明,混合励磁的步进电机有着优于普通电励磁电机的性能,对两相八极式电机来说,在获得一定保持转矩的同时,矩角特性更加平滑,转矩脉动减小.     

基于单片机的步进电机控制系统设计

为实现PC上位机或单片机单独控制步进电机,提出一种基于MSP430FG4618单片机实现的步进电机控制系统。利用单片机USART模块与PC机之间的串行通信或硬件矩阵键盘．通过脉冲分配器PMM8713和驱动器PMM2101控制步进电机的各种运行方式,实现三相或四相步进电机在不同工作方式下的启停、转向控制和调速等功能。通过输出转矩测量,系统从0～1．5A增大过程中最大静转矩与电流有着近似的线性关系,估算误差在10％左右,验证了系统的合理性。     

基于单片机的步进电机控制系统设计

为实现PC上位机或单片机单独控制步进电机,提出一种基于MSP430FG4618单片机实现的步进电机控制系统.利用单片机USART模块与PC机之间的串行通信或硬件矩阵键盘,通过脉冲分配器PMM8713和驱动器PMM2101控制步进电机的各种运行方式,实现三相或四相步进电机在不同工作方式下的启停、转向控制和调速等功能.通过输出转矩测量,系统从0～1.5 A增大过程中最大静转矩与电流有着近似的线性关系,估算误差在10%左右,验证了系统的合理性.     

单相无刷直流电机的设计分析与建模仿真

文中针对单相无刷直流电机结构设计及驱动方式展开研究,推导出电机理想工况下的基本方程,根据工程实际需求并结合无刷直流电机的设计原则确定该电机的设计方案。利用设计方案设计一台额定功率38 W,额定转速750 rpm的单相无刷直流电机,并分析了渐变气隙对电机起动性能和齿槽转矩的影响,确定了最优气隙长度。通过对比单极性绕组和双极性绕组形式的优缺点确定绕组形式,结合传统电机设计公式确定绕组匝数。文中利用有限元法初步验证了设计方案的合理性。根据电机动态数学模型在Simulink环境中搭建了电机系统的模型,仿真得到电机的转速、转矩变化曲线,结果与理论分析吻合良好,验证了电机设计方案的合理性和电机模型的有效性。     

基于XC2267M的仪表盘步进电机控制

随着现代电子技术的发展,中高档汽车上的组合数字仪表越来越多地采用“机电一体化”的步进电机。步进电机又称脉冲电动机,它能将输入的脉冲信号变成不连续的机械动作,是一种将电脉冲转化为角位移的执行机构。对步进电机的每一相来讲,输入的是一个脉冲列,只要控制好电脉冲,就能精确控制步进电机的角位移量,转速和转矩。     

开关磁通永磁同步电机的结构参数研究

以一台三相12/10极样机为例,介绍了一种磁通切换型双凸极永磁同步电机的结构特点和运行原理,并基于有限元法,详细研究了其结构参数气隙和永磁体厚度对电机性能的影响,具体包括对电机高速运行时的弱磁控制和电机绕组的电感、平均电磁转矩和力矩波动、定位力矩电机系统的机械特性和输出功率等。通过分析得出了对磁通切换型永磁电机气隙及永磁体厚度的选择原则,所得结果为该种电机的设计、性能分析以及运行控制等建立了基础。     

永磁体助磁的单相双凸极电机优化设计

针对永磁体助磁的单相双凸极电机优化设计问题开展了研究,推导出电机理想运行工况下的基本方程,并结合开关磁阻电机的设计原则总结出该电机的设计步骤。文中采用锥形气隙实现电机的自起动,然后利用总结的设计步骤设计了一台额定功率45 W,额定转速2 000 r·min^-1的永磁体助磁的单相双凸极电机。通过仿真计算电机主要结构参数对效率和齿槽转矩的影响并归纳出其规律性,为电机优化提供了参考。文中讨论了锥形气隙比率与电机起动能力的关系,并利用田口实验设计方法对电机进行了优化。优化后电机效率为89.86%,相比优化前提高了4.46%,证明了电机设计及优化的有效性。     

关于指针式电子手表中的步进电机

周荣太同志: 来信中提及电子手表中步进电机转矩的产生,实际上不是在它的电路部分,而主要在一对坡莫合金的定子和一个微型永磁体转子. 这种步进电机在钟表工业中常叫做双极型步进电机.它只要求电路供给一个正负交替而又有足够幅度的脉冲电压(波形如图1所示),它的转子就能自动定向地旋转.当然,这个脉冲电压的频率有一定的限度,     

Independent field-oriented control of two split-phase induction motors from a single six-phase inverter

Split-phase (six-phase) induction motor stator windings consist of two sets of three phase windings, which are spatially phase separated by 30 electrical degrees. Due to mutual cancellation of the air gap flux for all the 6n/spl plusmn/1 (n=1,3,5...) order harmonic voltages, called zero sequence components, large harmonic currents are generated in the stator phases. Only the 12n/spl plusmn/1 (n=0,1,2,3...)-order harmonic voltage components contribute toward the air gap flux and electromagnetic torque production in the machine. In this paper, a novel scheme is proposed where two six-phase induction motors are connected in series with proper phase sequence so that the zero sequence component voltages of one machine act as torque and flux producing components for the other. Thus, the two six-phase motors can be independently controlled from a single six-phase inverter. A vector control scheme for the dual motor drive is developed and experimentally verified in this paper.     

Comparative Assessment of Several Nutation Motor Types

A new type of pneumatic stepping motor, named a nutation motor, has been developed. By using a simple mechanism in a compact body, this motor can generate high torque. The nutation motor consists of three small linear pneumatic actuators and a gear-reduction mechanism that transforms their motion into rotation of the output shaft. Driving each pneumatic actuator sequentially with pneumatic digital signals results in nutation of the input bevel gear, which causes the output shaft to rotate. In this paper, the structure, working principle, and theoretical characteristics of a pneumatic nutation motor are presented. The design and fabrication of five prototype models and the results of experimental evaluations are also reported in detail. The prototype motors range in size from 10 to 50 mm in diameter and from 11.5 to 49 mm in length. It was found that the torque/volume ratios of the pneumatic nutation motors were about 2–29 times larger than those of a typical conventional electromagnetic geared motor.      

A low-cost sensorless technique for load torque estimation in ahybrid stepping motor

This paper presents a method of torque measurement in a hybrid stepping motor without the use of speed or position sensors. It is shown that torque ripple can be minimized by appropriate shaping of the phase-current pulses and that efficiency can be maximized when the level of mechanical load applied to the shaft is known. A controller is described which generates a signal related to the mechanical load by observation of the phase-current profile using a novel low-complexity technique. Practical results are presented, showing the torque estimation relative to measured torque     

High dynamic control of a three-level voltage-source-converter drive for a main strip mill

A high dynamic control system for the Alspa VDM 7000 medium-voltage drive was implemented, which provides fast torque response times of a few milliseconds despite the typically low switching frequency of gate-turn-off thyristors which is necessary to achieve high efficiency. The drive system consists of a three-level voltage-source converter with active front end and a synchronous motor. The drive has most recently been applied to a main strip mill. It provides a maximum of 8.3-MW mechanical power with a rated motor voltage of 3 kV. Besides motor torque as the main control objective, the control system has to comply with a number of additional objectives and constraints like DC-link voltage regulation and balancing, current and torque harmonics, motor flux, and excitation.     

A Modular and High-Precision Motion Control System With an Integrated Motor

This paper describes the design and control of an integrated direct-drive joint suitable for applications that require a high-precision motion control system. The joint integrates a direct-drive synchronous motor with axial air gap, a torque sensor, and a high-resolution position sensor. The key design aspects of the integrated joint, like the motor's armature, cooling system, motor housing, bearing arrangement, sensors, and power electronics are detailed. We also present a number of advanced implementations in motor torque control, optimal joint torque sensory feedback, and motion control using positive joint torque feedback. Experimental results illustrate an outstanding performance regarding thermal response, torque ripple, reference trajectory tracking, torque disturbance rejection, and joint stiffness.     

Damping a hybrid stepping motor with estimated position and velocity

It is well known that microstepping reduces the resonance behavior of stepping motors since the rotor moves in a sequence of very small steps. However, the under-damped nature of the motor does not change. In this paper, a scheme that uses microstepping and closed loop position control to stabilize and reduce resonance damping of the motor is proposed. The motor currents are controlled in a frame rotating synchronously with the excitation frequency. The d-axis current provides the torque to oppose the external load, and the q-axis current provides the transient torque to damp the motor. The motor velocity and position are estimated via an observer that tracks the angle of the motor back EMF voltage. The response of the closed loop system is independent of the external load level. Both simulation and experimental results have shown that the proposed control scheme is very effective in damping out the resonance of microstepping-controlled motors.     

Characteristics and control of a bidirectional axial gap combinedmotor-bearing

Introduces the design characteristics of a bidirectional axial gap combined motor-bearing where the flat disc motor has both rotation and axial position control capability. This motor consists of a disc rotor with a stator on each side of the rotor. The axial motion of the rotor is actively controlled while the other axes are constrained by additional passive or active radial magnetic bearings. Each stator produces a rotating magnetic flux in the air gap, to generate the motor torque. The axial force is controlled by changing the amplitude of the rotating flux. Both permanent-magnet motor and induction motor versions were analyzed theoretically and tested experimentally. The results demonstrated the capability of providing both the functions of a motor and a magnetic bearing