ITCC在40000Nm~3/h制氧空压机上的应用

介绍了汽轮机一压缩机综合控制系统(ITCC)的硬件构成、软件实现方法以及主要功能。该系统采用可编程控制器(PLC)及人机接口(HMI)技术,将汽轮机速度调节、压缩机防喘控制和紧急停车等功能形成有机的整体溶入一个PLC控制系统中,使控制功能紧凑协调、提高可靠性,效果良好。     

转炉倾动变频器控制系统改造

针对转炉倾动抱闸PLC控制功能上的缺点,采用了PLC控制与变频器控制相结合的方式,达到了理想的抱闸制动效果。     

基于PLC的步进电机运动控制系统的设计

以自动配料系统中配料小车为例,设计了基于PLC控制的步进电机运动控制系统,介绍了系统的硬件和软件实现方法。系统采用S7-300PLC和定位模块FM353。     

铜电解阳极生产线定位控制系统设计与应用

结合铜电解阳极自动生产线的工艺流程特点,介绍了由变频器、旋转编码器、PLC组成的异步电机的定位控制系统,并以阳极整形机组中的某链运机定位控制系统为例,对定位控制进行了讨论,分析了系统的工作原理和定位过程,提出了系统控制软件流程,解决了该链运电机的定位停止不平稳的问题,从而实现了链运机停止位置高精度控制。     

PLC在输煤程控系统中的应用

榆煤程控系统能够完成电厂正常运行时的上煤、配煤控制及设备、运行状况的监测及安全联锁、保护等功能.软件主要由监控软件、编程软件.它们分别实现PLC上位机人机接口的监视和控制、PLC逻辑控制功能以及系统内部、外部的数据接口.     

基于长度定位控制的带尾剪切计算优化

长度定位控制是冷轧后处理线达到工艺控制目的、满足设备功能精度要求的一个重要控制环节.首先介绍了双切剪系统结构,PLC系统协调控制完成带钢甩尾定位;其次阐述了带钢长度定位控制原理;最后结合脱脂带尾废料分切案例,详细分析带钢残留问题发生原因和解决思路,采用剩余长度平均分配的方法动态计算带尾分切长度,实现带尾废料变长剪切.该...     

ABB变频器在电铲中的应用

近年来,变频技术得到了迅速的发展,直接转矩控制方式使变频器交流调速技术得到很大的突破.电铲电气系统的全数字化即采用变频器对内部电机进行速度控制更能满足控制要求.介绍了电铲中PLC控制变频器的交流电机调速:PLC-变频器控制、通讯方式和参数设置、变频器的制动单元等.     

冷轧1550mm轧机飞剪控制策略

介绍柳钢1550mm冷连轧飞剪控制系统的控制数学模型,包括飞剪剪切角计算模型、飞剪剪切距离计算模型和飞剪速度目标值计算和速度转矩调节模型等。采用该数学模型实现飞剪自动剪切、定位和制动,将轧件的平均剪切误差控制在15cm以内。     

西门子S7—400单一调节器改为多功能调节器

介绍了用西门子S7-400型PLC内部单一的PID调节器实现多功能PID调节的技术,以适应不同的工业控制过程.由于S7-400型PLC内部PID调节器是只有一种位置型PID调节器,不能满足工业过程控制的需求,用软件的方法将它改造为多功能调节器,实现了微分先行、不完全微分等PID调节.通过这种方式的改造可增强S7-400型PLC的模拟控制功能.     

电解工艺行车的速度控制策略

重点阐述了电解工艺行车的速度控制系统。硬件上对编码器、变频器及PLC控制系统等主要部件的功能及原理进行了阐述,软件上重点叙述了变频器的参数设定及PLC的速度控制算法。     

利用高速计数模块进行定位控制及研究

利用PLC高速计数模块直接将外部编码器发出的脉冲读入,在PLC内部编程,通过程序控制完全能取代位置控制器的所有功能,从而省出位置控制器这一环节。     

Application of MintDrive Automatic Precision Positioning System

It is very important to locate batteries accurately and quickly during automatic battery production.Unstable or inaccurate location will negatively influence battery's consistency, quality and finished product rate.A traditional way is using sensor to detect and locate batteries directly , but because of the detecting tolerance, setting them on a fixed point exactly is almost impossible.This problem could be completely solved by the application of mint drive automatic accurate servo locating system.Firstly operating software WorkBench test was applied to collocate the servo locating driver for a most optimized control.Then based on the requirement of real location, program and test the locating action with a programming software and finally upload all the locating information to MicroLogix 1200 PLC, the PLC will control the running on each station telling when to locate, where is the location and how to eliminate bad parts.For this intelligent servo locating system has the advantages of powerful function, simple operation, high controlling and locating accuracy and easy maintenance, it is very suitable to be adopted by automatic battery making line.It is regarded as a very advanced method of control currently for reducing waste material due to inaccurate location and tough adjustment.     

Application of MicroLogixTM 1200 PLC in Battery OCV Test

The application of MicroLogixTM 1200 PLC made by American AB Company in battery automatic production line located in Inner Mongolia Rare Earth Ovonic High-Power MH/Ni Battery Co., Ltd was introduced.OCV namely open circuit voltage could be somewhat different because of the build materials of negative electrode, positive electrode and electrolyte.So OCV test can check the voltage value of electrolyte filled cells and figure out if the value is within the process specification.MicroLogixTM 1200 relay output type PLC, DeviceNet communication card, variable speed driver, Panelview 1000 color touch screen and some other hardwares were chosen.Then programme by using RSLOGIX500 software, a flexible and skillful use of shift and XOR command in PLC system can make the equipments realize the high automation.Through DeviceNet network based on CAN and with the advantages of quick response and high reliability transmit the information to supervise and control master panel, the system with these components can successfully realize proceeding the battery OCV test and control.The equipments are running stably, locating and test accuracy satisfy the process request.     

西门子PLC在工业热处理电炉中的运用

将西门子PLC应用于电炉控温,采用FB58控温功能块控温,达到自整定PID参数,极大地提高控温精度,降低了投资费用,使用效果良好.     

Regulation of the function of P-glycoprotein by epidermal growth factor through phospholipase C

Many multidrug-resistant (MDR) cell lines overexpress the epidermal growth factor receptor (EGFR) as well as P-glycoprotein (P-gp). However, the role of the increased EGFR in P-gp-mediated drug resistance remains unclear. Since recent studies suggest that activation of phospholipase C (PLC) could increase the phosphorylation of P-gp, and activation of the EGFR would also activate PLC, we investigated whether the effect of epidermal growth factor (EGF) on the phosphorylation of P-gp was mediated through PLC. Treatment of the human MDR breast cancer cell line, MCF-7/AdrR, with EGF increased the phosphorylation of P-gp by 20-50%. The increased phosphorylation of P-gp was accompanied by stimulation of PLC activity, as measured by the production of inositol, 1,4,5-trisphosphate and diacylglycerol, products of phosphatidylinositol-4,5-bisphosphate hydrolysis. Treatment of MDR cells with EGF also had detectable effects on P-gp function. For example, following incubation of MCF-7/AdrR cells with ECF, we observed a consistent decrease in total vinblastine (VBL) accumulation. Kinetic analysis revealed this change to be due to an increase in membrane efflux. The latter was measured by the initial uptake velocity, which was inhibited by EGF. VBL uptake measured at 0-320 sec was inhibited by 20-40%, which was associated with a similar increase in VBL efflux. EGF had no effect on drug accumulation, uptake, or efflux in sensitive MCF-7 cells. These data indicate that EGF can modulate the phosphorylation and function of P-gp, and suggest that this effect may be initiated by the activation of PLC.     

悬挂式输送链不同步现象改造及分析

分析了悬挂式输送链不同步的原因,提出了原有控制方式改造方案,通过几种方案的对比分析,最终确定采用可编程控制器PLC及变频器对双边链条运行出现的不同步进行自动调整的方式进行改造,并详细分析了该改造方案的可行性及实施方法。     

基于C语言的SIMATIC TDC功能块的研究开发

针对西门子PLC在工业控制中广泛应用,阐述其高端控制系列中SIMATIC TDC功能块的架构,采用C语言的方法实现SIMATIC TDC功能块。分析了功能块的基本结构,同时给出了功能块基于C语言的代码实现;对基于C语言的功能块的生成过程进行了分析。研究表明,利用C语言能够开发出更为灵活且复用性更高的SIMATIC TDC功能块。     

基于分布式网络的真空自耗电弧炉之控制系统

在真空自耗电弧炉的研制过程中,控制系统的设计是其中的关键和难点。本文提出一种用于真空自耗电弧炉的分布式控制系统,即由工业控制计算机和多台PLC组成,利用计算机的高速运算能力和PLC高可靠性的有机结合,实现系统的控制功能分散化和管理功能集中化,大大改善了系统的可靠性,提高了系统的自动化程度。实践证明,分布式控制系统较之传统的单机控制系统在结构上更加灵活,布局更为合理,运行可靠,操作方便,并在应用中取得了良好的控制效果。     

可编程控制器（PLC）的应用及维护

阐述了PLC的组成和工作原理，分析了来自工业现场的控制回路的干扰、信号残干扰、输入输出信号干扰以及执行机构不可靠等干扰因素。这些干扰将直接影响到PLC甚王这整个控制系统在工业现场中应用的安全性和可靠性。在结合多年实战经验基础上，总蛄出针对工业现场内对PLC产生影响的各种干扰源的应对措施。这些措施包括安装时应注意的事项。接地残处理应遵循的原则。提高输入输出信号争执行机构可靠性的方法。以及加强PLC的日常堆护。这样。可提高系统信号传输的准确性。增加PLC控制系统的控制的可靠性，避免由于机器误动作而造成的事故。     

基于S7—300PLC的铝电解多功能机组遥控系统设计

介绍无线遥控技术与西门子S7—300PLC的配合使用情况,通过PLC的通讯模块与profibus总线相连,代替传统的继电器控制方式,顺利实现铝电解多功能机组的各个功能和动作,接线简单,维修方便,设备故障率低。