变速箱试验台控制系统

采用全数字化、全网络化集散控制技术和电功率封闭技术模拟变速箱的全部工作状态、过程:驱动-发动机制动-反拖-换档-离合器结合驱动等,完成正拖换档、正拖加载、反拖加载和反拖换档等.检验自动变速箱换档动作时序及各种因素对变速器换档时的影响.用于控制和测量变速箱的转速、转矩、功率、传动效率、温度等各种参数.动力系统的驱动、加载电机采用单独变频器驱动,驱动部分和加载部分组成电功率闭环,加载电机将产生的电能回馈到直流母线乃至电网,达到较好节能效果,实现电能循环.     

矿用高压变频电传动试验系统陪试方案优化

以逆变器驱动加载电机串轴耦合变速齿轮箱和陪试电机为基本结构,运用运筹学最短路径问题的Floyd算法,优化配置加载电机极数及其与变速齿轮箱变速比。利用双三相电机的双功率和过载能力,扩展试验能力,减少陪试电机数量。应用直接转矩主从控制技术,实现双三相异步电机转矩和转速控制,满足试验加载需求。     

牵引电机负载模拟系统的转矩控制方法

基于轨道车辆牵引传动机构的物理模型,对牵引电机的负载转矩进行数学建模;针对阻尼负载转矩和惯性负载转矩2个部分分别提出直流负载电机电磁转矩的控制方法;按照加速时间不变原则,提出牵引电机牵引性能曲线按照负载模拟平台的功率进行等效缩放的方法;结合CRH2A型动车组的实车参数对上述方法进行仿真验证;在3.5 kW负载模拟平台上完成阻尼负载转矩实验,仿真和实验结果均证明所提出的转矩控制方法合理有效,能够准确模拟实车牵引电机负载.     

一种新型电机直接转矩控制的仿真研究

介绍了ALA转子电机的结构及其优良特性,但ALA转子电机不能在线直接启动.通过变频器启动也存在振荡区,对此采用直接转矩控制,仿真结果表明有很好的效果.     

通用变频器矢量控制与直接转矩控制特性比较

矢量控制与直接转矩控制作为当前两种主要的交流电机变频调速传动控制策略,在实际中得到广泛的应用.本文是以矢量控制与直接转矩控制策略比较为核心,在对两者进行了理论分析的基础上,在变频器-异步电机试验平台上进行了试验对比,给出两种控制策略下异步电机电磁转矩稳态和动态响应性能试验结果.     

变频矢量控制在电池生产线中的应用

矢量变频器是以磁场监控、智能控制等现代控制理论为基础直接控制力矩的,其内藏电流矢量控制功能可以实现高力矩控制、高精度速度性能。由于在变频器设计中采用了最新的磁场监控、智能控制、抗干扰控制,使控制性能大幅度提高。变频矢量控制通过对电机磁通电流和转矩电流的解耦控制,实现了转矩的快速响应和准确控制,可以以很高的控制精度进行宽范围的调速运行,并适用很多直流传动的场合,如造纸、冶金、纺织等。本文介绍的是矢量变频器在冶金工业中的一个应用,即电池锌板生产线的变频控制系统。该生产线主要用于电池锌筒、锌饼的生产,是将熔融…     

PMSM超前角弱磁控制的研究

在整个控制系统中使用了电流、转速和电压的三闭环控制,以电机端电压对变频器直流侧电压的利用率为基础,检测提供给电机的交直轴电压,与给定的电压值相比较组成新的电压控制环,由电压控制环形成电机弱磁的超前角。通过仿真验证了使用的超前角弱磁可以做到在id=0的恒转矩区平滑的过渡到弱磁控制的恒功率区,整个控制切实可行。     

考虑参数变化的永磁同步电动机弱磁控制研究

永磁同步电动机的弱磁控制是通过增加定子直轴负向电流,利用直轴电枢反应使电机气隙磁场减弱,达到等效于减弱合成磁场的效果以实现弱磁增速的目的,这就造成弱磁运行时,转速越高对应的直轴负向电流越大,即电枢反应越严重.直轴电枢反应严重影响着直轴同步电感,同时交轴电流也在一个较大的范围内变化,交轴电流的变化也影响着交轴同步电感和永磁体产生的磁链.当电机参数在运行过程中发生较大变化时,便造成了转矩给定值和实际系统的转矩输出能力之间存在一定的偏差,使得系统无法跟踪指令值,导致整个系统性能下降.当电机参数发生变化时,为了提高系统的控制性能,本文提出了转矩模糊控制器,从而使给定转矩较好的跟踪电机实际转矩输出能力.     

将普通交流异步电动机用作低速大转矩步进电机

利用变频器和PLC可编程控制器进行控制,可以将普通交流异步电动机用作低速大转矩步进电机,文章介绍了这种步进电机系统的工作原理、系统构成和调试方法.实践证明,用这种控制方法可以完成异步电动机的步进运动.     

卷绕传动中变频器卷径自动计算的变张力转矩控制模式

提出了一种卷绕传动中利用变频器实时完成卷径自动计算的变张力转矩控制模式.介绍了德国进口NWT生产线中卷绕传动部分的工作情况和控制原理;讲述了Lenze 9326伺服变频器的功能块和参数设定方法;最后,根据工艺要求详述了利用变频器实时完成卷径自动计算的变张力转矩控制模式的实现,并给出了在线卷径自动计算的方法和卷绕用变频器中的信号流图.     

基于粒子群优化算法优化陷波器参数的永磁同步电机振动抑制技术方法研究

针对振荡问题，在工业控制系统中，电机与负载之间一般都是通过传动轴、齿轮或者联轴器等传动机构进行连接，然而传动机构有一定的刚度系数，并不是完全刚性的，因此电机和负载之间存在柔性传动，即“末端振荡”。永磁驱动控制系统机械谐振抑制的综合设计是电机驱动领域的关键共性技术，对于提升永磁电机控制系统动态响应品质、提高系统安全性具有十分重要的意义。本文提出了一种基于智能算法的共振抑制方法，可有效解决陷波器由于参数耦合导致难以整定的问题，解决了伺服系统中多轴共振问题，既发挥了粒子群优化算法的优化计算能力，又体现了陷波滤波器有效滤除谐波的优点，将二者融合起来，有效消除了永磁同步伺服电机的共振谐波，抑制伺服共振现象。     

Synchronous Control of a Static AC Induction Motor Drive

Conventional methods of controlling an induction motor utilize regulation of stator current and motor slip frequency in order to maintain system stability. This control strategy requires a shaft speed feedback and fast-response current regulation. An alternative method of controlling an induction motor is presented which achieves the necessary system stabilization by controlling only the motor frequency. The control inherently regulates the motor torque angle by properly adjusting the phase of the converter firing signals. By synchronizing the inverter firing pulses to the motor back electromotive force (EMF) possible adverse inverter operating modes are avoided. The concept of synchronous control eliminates the preprogrammed functional relations previously required and allows the control to adapt to any desired motor flux level. Any desired outer regulating loop can be incorporated to form a fast-response wide-range ac drive system.     

Load-Commutated Inverter/Synchronous Motor Drive Without a Shaft Position Sensor

Synchronous motor drives are beginning to enjoy renewed popularity for certain applications such as flywheel energy storage. One of the reasons is that a synchronous motor drive can be made self-commutating so that the inverter becomes equivalent to a conventional phase-control bridge converter without large commutating components. The drive to be controlled consists of an inductor alternator coupled to a flywheel that will be used for temporary energy storage. The flywheel speed will vary over a two-to-one range; thus full performance can be achieved using a load-commutated inverter. A simple auxiliary commutating circuit is provided only for initial starting. The drive must operate both from a fixed dc voltage source (battery) and from a variable dc voltage source (dc motor), as it is intended for use in a battery-powered vehicle for load leveling. The load-Commutated inverter consists of two bridges connected in parallel so as to provide two-way power flow by reversing the dc current. The control system described does not use shaft position sensing, but senses the motor terminal voltage and the ac line current to determine the motor Nare internal operating conditions. This control method maintains the silicon-controlled rectifier (SCR) turn-off time as a constant percentage of the period of the generated back electromotive force (EMF) as speed and current are varied during operation. The inverter turn-off time is thus maintained by feedback control rather than the use of special function generators. A 20-kVA laboratory development drive system has been built and successfully tested using this control strategy.     

A sensorless variable structure control of induction motor drives

In this paper, an indirect field-oriented induction motor drive with a sliding-mode controller is presented. The design includes rotor speed estimation from measured stator terminal voltages and currents. The estimated speed is used as feedback in an indirect vector control system achieving the speed control without the use of shaft mounted transducers. Stability analysis based on Lyapunov theory is also presented, to guarantee the closed loop stability. The high performance of the proposed control scheme under load disturbances and parameter uncertainties is also demonstrated via simulation examples.     

智能斜井皮带机给煤控制系统设计

斜井皮带机给煤控制系统是煤矿控制系统的重要组成部分,由于工作面经常出水煤,导致皮带负载不断发生变化,引起主电机电流变化过大,对电机运行及整个机械系统极为不利,为此,本设计主要解决给煤机转速在提升电机电流变化的情况下,采用PLC控制,自动改变转速,从而进一步改变给煤量,最后达到有效保护皮带、电机的目的。     

基于负载观测的直流电动机调速系统无源控制

为了提高直流电动机调速系统的性能,提出了一种基于负载观测的直流电动机调速系统无源控制实现方法。负载观测器通过检测直流电动机的电枢电流和转速重构当前工况下的负载转矩。基于系统的端口受控耗散哈密顿模型,根据负载观测器估计的实时负载,运用互联与阻尼分配的无源控制方法,并采用参数切换进一步优化控制策略,实现对给定转速的快速、稳定跟踪。仿真结果表明采用所设计的无源控制策略,能使直流电动机调速系统具有良好的动、静态性能与较强的鲁棒性。     

基于双机直流拖动的智能配电系统自动开关系统设计

根据现代建筑智能配电系统中很多直流电机自动开关控制多轴传动系统的特点,通过对多轴传动系统简化折算,得到单轴拖动系统,即直流电机模型。应用PWM的变换器H桥的可逆电路对直流电机进行PWM驱动控制。在单闭环速度PI控制的基础上,设计了基于标准行程的位置调节方法,简述了转速、位置闭环的控制原理,通过MATLAB仿真验证了转速位置的闭环控制对双机直流拖动控制的有效性,实现了系统的结构简单、运行偏差小、运行稳定,设计了以C8051F320单片机和LMD18200直流电机集成驱动芯片为核心的硬件电路,经过最后的软硬件整合测试,证明系统性能良好。     

Evaluation of torsional oscillations in paper machine sections

Torsional oscillations greatly affect performance and determine the bandwidth (BW) and damping of speed loops. Backlash due to gear reducers can also contribute to the triggering of oscillations, especially when the drive runs at very low load torque. This paper presents a detailed evaluation of these effects in typical electromechanical drive trains applied to paper machine sections. The cases evaluated consider torsional oscillations in two-mass and three-mass systems, and the effect of shaft diameter and length on the resonant frequencies of three typical paper machine sections. Time-domain response plots are evaluated to show the effect of speed response overshoot, reducer backlash, and step or ramp speed commands. Based on these results, mechanical design guidelines are given for the most significant drive train components in order to minimize torsional oscillations of the speed-controlled drive system.     

PERFORMANCE ANALYSIS OF A D.C. DRIVE ELECTROMECHANICAL SYSTEM WITH ELASTIC COUPLING AND PULSATING LOAD TORQUE

ABSTRACT

This paper presents the analysis of a d.c. motor drive with a pulsating load torque and elastic mechanical link between the motor and the load. A mathematical model of the system using State Space technique is given and the equations are solved to obtain closed-form solutions for motor speed and current under transient and steady state conditions. The analysis reveals that the system performance is significantly affected by elasticity of the shaft and the nature of pulsation of load torque     

开关磁阻电机非线性计算及动态系统仿真研究

基于ANSYS和Simulink对整个开关磁阻电机驱动系统建模、仿真.将有限元与控制结合对开关磁阻电机系统非线性特性进行仿真研究.通过对整个电机系统的研究建立一种快速、准确的非线性系统仿真环境,从而有助于对开关磁阻电机进行深一步研究、设计与控制.最后通过对样机低速运行情况下进行电流斩波控制仿真试验,验证结合有限元计算与控制系统仿真分析对开关磁阻电机非线性以及动静态特性研究的有效性.