Interfacing Modern Drives with Mill Distributed Control Systems

Present-day drive systems are all-digital and have taken on the characteristics of a drive-level distributed control system with a high-speed communications system encompassing the master, drives, and operator's controls. The interface with the next higher level in the mill control hierarchy, the distributed control system, must reflect these characteristics. The speed of response required for direct manipulation of the drive system is very fast. Consequently the slower distributed control system is used primarily to monitor and perform relatively long-term control functions on the drive system. Local machine operator controls are required for safe direct command control of the sections. An adequate communications link may be established through conventional programmable controller highway protocol and hardware.     

轧机主传动交流变频传动技术的发展及应用

针对不同轧制工艺对主传动电控系统的性能要求,分析了当前在大型轧钢厂主轧机电气传动中主要的几种变频调速方案,并对其优缺点及适用范围进行了比较。重点分析了采用新型可关断电力电子器件的三电平脉宽调制(PWM)变频调速系统的结构特点,并对不同器件的优缺点进行了比较。对目前我国大功率轧机主传动交流调速系统的应用和发展现状进行了探讨。     

Rolling Mill Reel Drives

During the past few years there has been significant progress in the technology and hardware available to the electrical engineer. Accordingly, drive capabilities and limitations have changed, justifying a restating of application criteria pertaining to reel drives. As an aid in specifying and utilizing reel drives, this paper discusses application techniques and guides based on today's technology.     

轧机主传动交流调速技术的现状与发展

讨论了当前大功率轧机主传动采用的交流调速系统,比较了交交变频,LCI交直交变频,IGCT/IGBT三电平PWM变频等交流调速系统的特点.讨论了轧机主传动机电振动的原因及抑制方法.还介绍了中国大功率轧机主传动交流调速系统的现状与发展.     

Large Grinding Mill Drives Update

The trend to larger grinding mills with the attendant increase in motor drive horsepower has affected the options for drive equipment. Also the development of large adjustable speed drives has created new possibilities for mill drives. Grinding mill torque characteristics, drive requirements, and torsional excitations of the various types of available drives will be briefly reviewed.     

Evaluation of Large Grinding Mill Drives for the Cement Industry

Mill drives for the cement industry have rapidly increased in horsepower during the past few years. There appears to be no limit in size. Because of this increase in horsepower, the application problems have become more complex. The usual type of mill drives may not provide the optimum performance and cost. Nonconventional drives should be included in the evaluation. The significant types of drives available are reviewed, and the electrical performance and economics of each type are evaluated. Gearless-type drives are in the study. Gearing, however, is not included in the evaluation. No attempt is made to recommend one drive over any other.     

火电厂中速磨永磁调速驱动系统的应用和分析

目前由于我国大容量火电机组的体量巨大,现役机组的节能减排将成为"碳达峰"和"碳中和"发展之路上的主要过渡方式.提出一种用于大容量机组的磨煤机永磁调速驱动方式,可有效缓解异步电动机功率因数低、能耗高的问题.永磁调速驱动方式相较传统异步电动机驱动系统具有控制智能、功率因数高、效率高、可靠性好、节能效果优良,以及布置及检修维护方便等优点.通过某示范电厂采用该系统的技术分析、实测数据以及经济分析,进一步阐述永磁调速驱动系统的优越性,可广泛应用于大容量火电机组的转型之路.     

A New Approach to Cold Mill Drive Equipment Air Cooling

Dominion Foundries and Steel Limited (DOFASCO) of Hamilton, ON, commenced single-shift production on the new No. 2 Five-stand Cold Rolling Mill in July 1976. The mill employs a new integrated systems approach to the cooling of the mill drive motors, associated electrical control equipment, mill process and service areas, and buildings. The new approach represents an improvement in cold rolling mill electrical equipment cooling and ventilating methods. As described, the new approach results in cost and operating advantages over established methods.     

USS总线用于离心机驱动系统

我公司XJZ1600-N糖用上悬式离心机的驱动系统是由西门子SIMOVERT MASTERDRIVERS VC的AFE整流回馈单元与逆变器组成的可逆变频调速系统。在对AFE整流回馈单元与逆变器的控制上,根据两者的工作方式而采取了不同控制方式。由于AFE整流回馈单元在启动之后就无需做任何改变,因此,仅使用了PLC的一个输出点来控制AFE整流回馈单元的启动和停止,另外取AFE整流回馈单元的故障信号作为PLC的一个输入点,使PLC能够知道AFE整流回馈单元是否正常工作,从而做出上位机“主”SIMOVERTMASTERDRIVES“从”SIMOVERTMASTERDR…     

高性能变频调速系统的几个应用问题

介绍高性能变频调速系统的几个应用问题:双闭环系统的特点及几个注意事项;如何利用预控改善系统启动、制动转速跟踪性能和抗负载扰动能力;张力控制系统;位置控制系统和宽调速范围转速控制系统的极低速控制;变换器无滞后模型及电流环准连续控制;4种柔性机械联接系统的振荡抑制。     

Load Sharing of Dual Motor Grinding Mill Drives

Relatively small slowly varying shaft position and velocity variations superimposed on the normal running speed of dual drive grinding mill motors can cause individual motor torque variations which disturb load sharing. The magnitude of load or torque unbalance is a function of the magnitude of the mechanical variation, the type of motors used, i.e., induction or synchronous, the number of motor poles, and the ratio of the gear connecting the motors to the load. When the magnitude is large enough to be of concern, it can be compensated for through motor secondary or field controls. How the causative factors relate, how dual drive motors should be specified for purchase are discussed, and a compensating load sharing controller for dual drive synchronous motors is described.     

Selection and Application of Variable Speed Motor Drive Systems

Several methods of varying speed are available. The considerations to be included in the selection of all-electric drive systems such as eddy current couplings, direct current drives, and ac inverters are presented. The intent is to point out some of the factors which should be considered when evaluating an application, then to incorporate these into the system design. Because each type drive has advantages for each particular application, the relative merits of the individual systems are numerous and are beyond the scope of this presentation.     

西门子SIMATIC PCS7在宝钢厚板厂的应用

介绍了厚板厂涂漆线的设备状况和工艺流程,着重讨论了西门子过程控制系统用于辊道控制PLC的软、硬件配置,及其程序组成和功能.突出了其PLC控制系统的分散控制,集中管理,安全可靠和方便维护的优点.     

风扇磨煤机叶轮前盘修复新工艺

针对采用常规工艺修复磨损严重的风扇磨煤机叶轮前盘时产生严重的焊接变形现象 ,提出了防止焊接变形的措施 ,为控制大面积变形创造了条件。通过实施焊前预热、焊后去应力退火等热处理方法 ,消除了内应力 ,稳定了金属组织和机械尺寸 ,提高了焊接质量和机械性能     

轧机传动系统的微机数字控制

本文概述轧机传动系统微机数字控制的国内概况，并以西门子产品应用为例，论述其硬件配置、软件功能原理、以及工程应用中的其他问题。     

20辊轧机板形辊驱动方案研究

可逆轧机板形辊与带材的不同步造成带材的表面划伤及卷径跳动,针对可逆轧机板形辊控制的工艺要求,在分析其原有控制原理的基础上,提出板形辊速度与带材速度不同步及张力波动的原因。通过对原有板形辊传动控制方案的改进及补偿转矩的优化,从而提高板形辊与带材的同步度,解决了卷径跳动及张力波动问题,提高了轧机运行的稳定性,从而有效地提高了带材的表面质量及产量。     

遗传优化模糊控制器在磨煤机系统中的应用

针对电厂中常见的钢球磨煤机制粉系统，设计了一种基于伪并行遗传算法的模糊控制器，并对多变量对象的适应度函数、交叉和变异算子等进行了改进，仿真实验结果表明该方法是可行的，经过优化的模糊控制器具有较好的鲁棒性和抗干扰性。     

轧机变流机组主传动的数字化改造

文章论述了采用大功率晶闸管主变器和多处理器数字控制，取代直流发电机变流机组和模拟控制系统，并且讨论了数字控制系统的配置，电源系统的高次谐波，以及取代机组变流装置后的经济效益。     

交流变频技术在攀钢热轧板主传动的应用

文章简要介绍了轧机交流变频调速技术发展现状，具体介绍了交交变频技术在攀钢1450热轧板厂的应用。