电磁阻尼对低速电机转子横向非线性振动的影响

对交流电机转子横振时电磁阻尼及考虑电磁阻尼时转子横振进行了研究.首先应用磁场理论求得了电机三相不对称运行时电磁阻尼力,并对三相对称时的电磁阻尼进行了计算.接着用拉格朗日-麦克斯韦方程求得了转子横向振动的方程,画出了三相对称时转子强迫振动的幅频曲线,并与实验进行了对照,实验结果与理论结果吻合的很好.     

采用微处理器的步进电机控制系统

步进电机是应用于机电一体化控制系统中的一种常用的执行元件.控制系统要求步进电机控制的设计要能更好地服务于整个系统,而微型处理器与微机技术的日渐成熟,其良好的性价比,可更好地服务于步进电机控制系统.根据步进电机的工作原理和其基本的控制方式,通过接口电路,使不同的步进电机在任意通电方式下被有效地控制,利用脉冲分配,实现通电方式,又根据其通电规律,由软件编程列出数据表,微型处理器强大的数据处理功能使编制软件查表法实现对各种步进电机的控制.在此基础上,对采用微处理器控制步进电机方法进行深入探讨,并给出适应多种步进电机运行方式的软件程序.     

Design and implementation of a position sensorless control method for brushless DC motors

Because brushless direct current (BLDC) motors have the advantages of a compact size, high power density, high efficiency, and long operating life time, they are widely used in many industrial products and electric traction systems. It is known that the BLDC motors have no brushes for commutation. They are commutated with electronically commutation. So, the rotor position information of the BLDC motors must be known to understand which winding will be energized according to the energizing sequence. In most of the existing BLDC motor drivers, rotor position information is detected by Hall effect sensors. This kind of mechanical position sensors will bring additional connections and costs, reliability decrease and noise increase. In order to improve the control performance and extend the range of speed regulation for BLDC motors, a position sensorless control method is proposed in this paper. In the proposed control method, rotor position information of the BLDC motors is detected from the back electromagnetic forces (back-EMFs) which are estimated by an unknown-input observer with line to line currents and line to line voltages. For the purpose of verifying the effectiveness of the proposed control method, a model is built and simulated on the Matlab/Simulink platform. The simulation results show that the speed regulation performance of BLDC motors is improved compared with using Hall effect sensors. At the same time, the reliability of the BLDC motors is improved and the costs of them are reduced because the position sensor is eliminated.     

带式输送机功率平衡方法的研究

本文研究了带式输送机多电动机驱动的功率平衡问题,提出了采用PLC控制调速型液力耦合器,实现带式输送机多电机驱动功率平衡的控制方案,并确定了控制系统的结构和组成。     

多台三相电机协同继电控制电路设计与优化

根据三相电机自制简易加工机器实例,采用单键控制的自动化操作,对三台三相电机协同继电控制整体电路和故障提示电路进行了优化设计,加快了机械加工的生产进度,提高了机械加工的稳定性和成品率.     

THE EQUIVALENT CIRCUIT AND CONTROL SYSTEM OF TRAVELLING WAVE TYPE ULTRASONIC MOTOR

从压电振子的等效电路出发，得到了行波型超声波电动机定子环乃至整个电动机的等效电路．分别对电机控制系统各组成部分进行了分析，并利用电机等效电路达到简化控制系统的目的．实验对研究结果进行了验证．     

周期性外力作用下双头分子马达运动机制研究

讨论了双头分子马达在白噪声及反馈控制的作用下,系统加周期性外部驱动力时,流随弹簧的原长、弹性系数及温度的变化.流随弹簧原长呈现周期性的变化,存在最优的弹性系数使流达到最大,它对温度的变化非常敏感.通过分析该环境中双头分子马达的运动机制,充分说明各个参量之间的相互协调能够反映出生物体机制的高度复杂性、协调性.     

Modelling and Simulation of System Dynamics of Hybrid-Driven Precision Press

Different from conventional mechanical systems with single degree of freedom (DOF),the main idea of the system of hybrid-driven precision press is to combine the motion of a constant speed motor with a servomotor via a two-DOF mechanism to provide flexible output. In order to make the feasibility clear, this paper studies theoretically the dynamic characteristics of this hybriddriven mechanical system. Firstly,the dynamics model of the whole electromechanical system is set up by combining dynamic equations of DC motors with those of two-DOF nine-bar mechanism deduced by the Lagrange‘s formula. Secondly through the numerical solution with the fourth Runge-Kutta, computer simulation about the dynamics is done, which shows that the designed and optimized hybrid-driven precision press is feasible in theory. These provide theoretical basis for later experimental research.     

交流圆弧磁悬浮感应电机机制研究

磁悬浮（无轴承）电机利用磁场力使转子悬浮并驱动其实现高速或超高速旋转．基于传统电机技术提出一种交流圆弧电机原理,并按电磁轴承悬浮技术,水平方向对称于转子布置2个圆弧电机,垂直方向对称于转子布置2个圆弧电机,构成交流磁悬浮感应电机;建立电机在干扰作用下转子与定子间的间隙（气隙长度）变化规律,基于电磁理论建立了气隙磁感应强度的分布规律,利用虚位移原理建立电机电磁悬浮力和电磁转矩数学模型;通过有限元分析对磁感应强度、电磁悬浮力和电磁转矩等分布特性进行了仿真研究．     

基于MC9S12DG128单片机智能车设计与实现

该智能车控制系统采用MC9S12DG128 16位单片机作为唯一的核心控制单元,加以直流电机、舵机、光电传感器和电源电路以及其他电路构成。由安装在车前部的反射式红外传感器负责采集信号,并将采集到的电平信号传入核心控制单元,核心控制单元对信号进行判别处理后,由PWM发生模块发出PWM波,分别对转向舵机和直流电机进行控制,完成智能车的转向与前进。智能车后轮上装有霍尔传感器,用来采集车轮转速反馈的脉冲信号,并经由核心控制单元进行PID控制算法处理后会自动调节输入到电机驱动模块的PWM波占空比,从而控制小车的速度。寻迹由RPR220型光电管完成。     

基于滑模直接转矩控制磁阻同步电机的仿真研究

ALA转子电机具有与普通电机不同的结构,但与普通电机一样,直接转矩控制也能改善其动态性能和抗干扰能力,同时也存在较大的电流、磁链和转矩脉动,逆变器开关频率不恒定,高频噪声等问题、为此,在速度PI调节器中采用了具有快速响应,对参数变化及扰动不灵敏的滑模变结构控制,仿真结果表明有很好的效果。     

基于USS现场总线的S7-1200和G120通信实现异步电动机变频调速监控网络的研究

文章提出通过USS现场总线将西门子S7-1200和G120变频器连接起来,组成多台异步电动机变频调速监控网络,并在HMI上实现人机交互。该控制系统成本相对较低、电缆数量减少、多台电动机可同时分别控制、电机运行状态实时显示,控制系统稳定性、可靠性、灵活性大大提高。     

智能小车系统的设计

基于信息社会日益智能化的发展方向,设计了具有自动控制、精确定位和探测功能的智能小车。该系统以小车模型为载体,以低功耗单片机MSP430F449为核心,实现自动控制功能,利用反应式步进电机实现探测系统的前进、后退、加速、减速与转向,达到精确定位的目的,再加上霍尔传感器、超声波传感器、光敏二极管、接近开关之间的相互配合,实现了小车的智能化探测,完成了距离与速度检测、避障、寻光入库、金属物体检测的功能。     

耳蜗外毛细胞Prestin的研究进展

哺乳动物耳蜗外毛细胞能响应膜电位变化，其长度和劲度(stiffness)均能发生迅速改变．外毛细胞的这种电动性被认为是由分子马达(motor)驱动，能产生耳蜗机械放大。Prestin特异地在外毛细胞内表达，近年的研究认为Prestin正是耳蜗外毛细胞的分子马达，对近年来有关Prestin的结构功能特性的研究结果进行了较详细论述。     

单相交流电动机磁场的疑点剖析

单相异步电机的脉振磁场可以分成两个转向相反的旋转磁场，并由此可以继续分析转子绕组的受力情况，但是，不能将单相绕组的两极与这两旋转磁场各自对应，并进而做出各种错误的猜想。异步电机旋转磁场的产生必须满足其最基本的条件，只有正确理解了电机的电磁关系才能把握电机的工作原理及工作特性。     

Reliability test for linear induction motors

Reliability is a very important target of linear induction motors. In this paper, the reliability model of the motor is established, the reliability indexes are defined, the faults’ modes are analyzed and classified according to their effect and damage, the sequential sampling plan is discussed and its acceptable fault rate (ACFR) and refusable fault rate (REFR) are presented, and then, the detailed reliability compliance field test method is introduced with one case. With the method, engineers can verify the reliability of linear induction motors expediently.     

电动机控制系统在抽油机上的应用

本文研究目标是油田企业的永磁同步电动机抽油机的变频控制方案,介绍了目前抽油机的技术发展现状以及应用领域,给出了永磁同步电动机在抽油机上应用的控制方案,结果表明,将永磁同步电动机应用于抽油机能够明显提高其工作性能和节能指标。     

Output speed and flow of double-acting double-stator multi-pumps and multi-motors

The primary focus of this study was to investigate a series of novel motors and pumps, based on a new type of structure called double-stator. The double-stator structure can be used as pump or motor just based on the application requirements. A certain amount of pumps or motors can be formed in one shell, and these sub-pumps or sub-motors can work alone or be combined without influence on each other. So this kind of double-stator pump (motor) is called a multi-pump (multi-motor). Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors, the mathematical expressions of the output flow rate and the rotational speed are acquired. The results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by electromotor. Likewise, when supplied by settled input flow, without complex variable mechanism, the functions of double-speed, multiple-speed, and even differential connection can be obtained by employing the use of a double-stator multi-motor. The novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor, and has broad application prospects.     

一种温差电效应发电演示热功小车

研制了一种温差电效应发电演示热功小车,演示了从热能到电能再到机械能的能量转换过程。该小车以温差发电为电源,利用珀尔帖片、散热片与酒精灯构成核心组件,由酒精灯加热下散热片,下散热片将热量集中到珀尔帖片,珀尔帖片通过上散热片散热,维持珀尔帖片冷热两面有较大温差,输出电能驱动电机旋转,电机带动小车跑动。该小车结构简单,工作原理明晰易懂,运动速度达15 cm/s,演示结果达到了引起人们对温差发电的关注和研究的目的。     

起重机的变频调速系统研究

讨论了起重机的电气传动特性和交流异步电动机的变频调速机械特性,交流异步电动机的变频调速机械特性在任何情况下都可以适应起重机的各种机构的电气传动特性,所以变频调速已成为交流异步电机的主要调速方式和发展方向．使用变频器变频调速可以使起重机的工作效率、平稳性、调速范围等性能大大改善．