PLC和变频传动技术在新钢210t精炼炉喂线中的应用

通过对PLC技术的开关逻辑控制,模拟量的开关检测并参与控制,和人机界面及上位计算机远程通讯控制等功能的组合应用,结合交流变频调速传动技术,构成了控制性能优良、功能完善,完全满足了新钢210精炼炉工艺技术要求的钢包喂线自控系统。     

用S函数实现非平衡条件下矩阵式变换器电流动态调制策略

在交流拖动系统中，变频电源设计是调速系统控制的关键。根据矩阵型变换原理，重组变频电源的主回路，并对调制策略和控制方法予以优化，使变频电源设计中的问题得到了较好的解决。利用MATLAB构建非平衡条件下矩阵式变换器的仿真模型，用S函数确定每个PWM周期内4个开关组合以及零开关组合的占空比，成功地实现了频率和电压的变换。     

基于神经网络的异步电动机直接转矩控制系统

直接转矩控制是继矢量控制变频技术后发展起来的一种新型具有高性能的交流变频调速技术。针对基于直接转矩控制的异步电动机运行时存在较大的电流及转矩脉动问题,提出了利用神经网络构造逆变器的开关状态选择器用于直接转矩控制,摒弃了滞环,系统实现更简单。仿真结果表明,该调速系统具有良好的动态性能,该设计是可行的。     

交流电机变频调速讲座——第二讲 静止式变压变频器

（接上期）为了实现异步电动机的变压变频调速，必须具备能够同时控制电压幅值和频率的交流电源，而电网提供的是恒压恒频的电源，因此应该配置变压变频器，又称VVVF（Variable Voltage Variable Frequency）装置。最早的VVVF装置是旋转变频机组，即由直流电动机拖动交流同步发电机构成的机组，调节直流电动机的转速就能控制交流发电机输出的电压和频率。自从电力电子器件获得广泛应用以后，旋转变频机组便逐渐被淘汰，并形成了一系列通用型的静止式变压变频装置。     

双PWM变频技术的应用研究

针对变频调速电动机再生能量回馈应用技术中存在的问题,本文采用双PWM变频调速技术,设计了一种基于固定开关频率的SVPWM电流控制的PWM整流器,并在机床电力拖动控制系统的应用中取得良好的控制效果。     

浅谈变频技术在家用电器上的应用

变频技术大致分为交流变频调速、无刷直流变频调速和开关磁阻变频调速等三种类型,并各有其优缺点,本文主要介绍了它在家电技术方面的一些应用。     

变频器在锅炉给粉系统的应用

文章介绍了传统锅炉给粉调速的缺点，锅炉给粉调速应用变频调速的意义及优势，例举了给粉变频调速系统的构成、设备选型，给粉变频调速系统的控制特点，给粉变频调速系统的上位机组态原则及PLC编程方法。     

基于SA866AE的VVVF调速系统的设计

设计了由PWM控制器SA866AE和功率模块IPMPS21865组成的变压变频（VVVF）调速系统,对相应的控制参数进行了计算和设定。该系统结构简单,容易控制,运行安全可靠。     

变频器和PLC在9米龙门铣床中的应用

本文提出了用交流变频调速取代直流调速的问题，分析了几种典型的变频器控制方法，给出了变频器及其周边设备的选型计算公式，概述PLC在变频调速中的灵活应用，简述在变频器和PLC安装中应注意的一些问题，最后介绍变频调速系统的调试情况。     

上海石化双速电机变频调速技术改造

介绍了应用变频调速技术对进口再割针梳机进行电气传动改造过程，简述了原双速电机调速系统所存在的问题，对原电气传动系统进行技术分析，提出应用变频调速技术设计变频调速系统来改造原双速电机调速系统，并通过实践说明进口设备通过变频技术改造，产生了明显的经济效益。     

Integral motor with driver and wireless transmission of power andinformation for autonomous subspindle drive

This paper describes the novel technology of an integral motor with the associated driver and wireless transmission of power and information (WTPI), which is effectively applied to autonomous spindle drive for the sophisticated workpiece machining. The power supply to the integral motor is made by way of a separable WTPI coupling. In addition, calculation for variable voltage and variable frequency (VVVF) control is done at the primary side of the coupling, and then the frequency command is transmitted to the secondary side by an overlapped transmission of the data on the power transmission through the WTPI coupling. At the secondary side, direct power conversion from the induced high-frequency voltage to the motor terminal voltage is conducted using a bidirectionally controllable power switch. The amplitude of the terminal voltage is adjusted by changing the inverter voltage at the primary side. In this way, the VVVF drive is made through the WTPI coupling, thus providing the integral subspindle with the autonomy for sophisticated machining     

A Designated Harmonic Suppression Technology for Sampled SPWM

With the development of motor-driven technology, the pulse width modulation (PWM) method plays a key role in the servo-control system and motor speed control. In recent years, sine PWM (SPWM) becomes the nucleus of a motor speed control system by means of variable voltage and variable frequency (VVVF). However, the harmonic component of the inverter output wave impairs applications in practice. As for applications, harmonic suppression technologies should meet the needs of high voltage a…     

High efficiency, unity power factor VVVF drive system of aninduction motor

A high-efficiency, unity-power-factor VVVF (variable voltage, variable frequency) drive scheme for an induction motor is presented. A unity-power-factor PWM (pulsewidth modulated) converter regulates DC voltage. An inverter circuit with the magnetic flux control PWM method generates VVVF PWM waveforms. The modulation factor of the inverter PWM control with controllable DC link DC voltage is studied. As a result, the distortion factor and the switching frequency are reduced by over-modulation with low DC link voltage. A high-efficiency and unity-power-factor VVVF induction motor drive has been achieved using the control strategy     

FPGA电流型PMSM变频驱动器及开路故障保护

电流源逆变器(CSI)随着反阻断IGBT器件的成功开发,在电动汽车等大功率变频调速领域前景广大。FPGA作为控制器,其时序控制能力强大,适合用来实现基于电流型空间矢量脉宽调制(SVPWM)技术的永磁同步电机(PMSM)变频驱动器。该系统通过采用最小直流链电流命令产生法和合理的死区开关状态设置,有效减小直流和开关损耗。系统为应对开路故障引起直流链电感产生瞬间高压打坏开关器件的现象,设置由双向TVS管和功率电阻构成的电感电压箝位环节,并监测直流链电流值,一旦低于限值则实现保护性停机。实际系统使用Xilinx公司FPGA开发板,基于电流源逆变器转子参考框下交流侧的理论模型,建立了一套数字化闭环调速策略,实测定子电流THD值及功率因数均达到良好效果。     

Comparison of energy-saving on the speed control of the VVVF hydraulic elevator with and without the pressure accumulator

The speed control system of variable voltage variable frequency (VVVF) hydraulic elevator with the pressure accumulator has been designed, which is a kind of the innovation energy-saving hydraulic elevator. The control system of the VVVF hydraulic elevator with the pressure accumulator is analyzed, and the speed control of the VVVF hydraulic elevator with the pressure accumulator is studied using the PID control algorithm. The comparison of the experimental researches of energy-saving is carried out for the speed control of the VVVF hydraulic elevator with and without the pressure accumulator. The experimental results show that the VVVF hydraulic elevator with the pressure accumulator has higher efficiency compared with the VVVF hydraulic elevator without the pressure accumulator.     

Solid State Voltage and Frequency Controller for a Stand Alone Wind Power Generating System

This paper deals with the voltage and frequency controller of a wind turbine driven isolated asynchronous generator. The proposed voltage and frequency controller consists of an insulated gate bipolar junction transistor based voltage source converter along-with battery energy storage system at its dc link. The proposed controller is having bidirectional active and reactive powers flow capability by which it controls the system voltage and frequency with variation of consumer loads and the speed of the wind turbine. It is also having capability of harmonic elimination and load balancing. The proposed electro-mechanical system along with its controller is modeled and simulated in MATLAB using Simulink and power system block-set toolboxes. Performance of the proposed controller is presented to demonstrate voltage and frequency control of a wind turbine driven isolated asynchronous generator along with harmonic elimination and load balancing.     

协庄煤矿1#副井绞车变频技术改造

变频绞车是以全数字变频调速为基础,以矢量控制技术为核心,具有低频转矩大、调速平滑、调速范围广、精度高、节能明显等优点：具备结构紧凑、体积小、移动方便、安全防爆、操作简单、运行安全稳定、故障率低、基本免维护等特点,对于煤矿绞车安全运行具有深远意义。     

Selective Harmonic Elimination PWM Control Scheme on a Three-Phase Four-Leg Voltage Source Inverter

A selective harmonic elimination (SHE) control strategy on a three-phase four-leg inverter is reported in this paper. The control signals of the four legs are calculated as follows: 1) control signals of three legs are mathematically expressed using Fourier-based equations on line-to-line basis as conventional SHE technology, which eliminates lower order nontriplen harmonics, and 2) the fourth leg produces the harmonics that are equal to the lower triplen harmonics produced by the other legs. The inverter has almost symmetric three-phase output voltage with unbalanced load because the fourth leg provides a low-impedance path for the triplen harmonics. The switching-to-fundamental frequency ratio is only 13 and 27 (per unit) p.u. for the three legs and the fourth leg in the proposed prototype, which is with the total harmonic distortion of output voltage lower than 4%. Selected solutions for the switching angles are presented and verified by simulation and experimentation in order to confirm the effectiveness of the proposed scheme.     

一种适用于恒定导通时间控制的高性能定时器电路

本文提出一种适用于恒定导通时间控制的开启时间定时器电路。电路中采用与输入电源电压成正比的电流对电容充电,从而实现定时器的定时时间与输入电源电压成反比,解决了传统恒定导通时间控制中系统工作频率随输入电源电压变化的问题。为了获得高的定时精度,开启时间定时器中的比较器采用了自适应偏置技术,根据输入电源电压的情况动态地设置定时器中比较器的偏置电流。基于0.6μmCD工艺,对所设计开启时间定时器电路进行仿真验证。结果表明,本文所设计的开启时间定时器电路,能够始终保证高的定时精度。同时由于定时时间与输入电源电压成反比,在系统中引入了前馈,极大地提高了系统的线性响应速度。