橡胶四辊压延机自动控制系统

论文

课题橡胶四辊压延机自动控制系统

学院

教育中心

专业

年级

学号

姓名

导师

定稿日期：年月日

摘要

本文介绍了国内四辊压延机的发展现状，以及存在问题，同时介绍了可编程控制器的工作原理，选型依据。设计了一种基于PLC的全自动四辊压延机，介绍了工作原理，并设计了电路，并根据直流电动机具有良好的起、制动性能，宜于在大范围内平滑调速，在许多需要调速或快速正反向的电力拖动领域中得到了广泛的应用。近年来，在电力电子变换器中以晶闸管为主的可控器件已经基本被功率开关器件所取代，因而变换技术也由相位控制转变成脉宽调制（PWM）；交流可调拖动系统正逐步取代直流拖动系统。然而，直流拖动控制毕竟在理论上和实践上都比较成熟，而且我国早期的许多工业生产机械都是采用直流拖动控制系统，所以它在工业生产中还占有相当大的比重，短时间内不可能完全被交流拖动系统所取代。

而调速系统按照不同的标准又可分为不同的控制系统。但是，从一定角度上来说，可以把调速系统笼统的分为开环调速系统和闭环调速系统。开环调速系统结构简单、容易实现、维护方便，但是它的静态和动态性能往往不能满足生产和控制要求。而闭环控制系统可以很好的解决这些问题，因此在实际生产中得到了广泛的应用。其中，转速、电流双闭环控制直流系统是性能最好、应用最广的直流调速系统。

本次课程设计是关于对基于PLC的四辊压延机系统的设计说明。

该系统具体主要关于1.四辊压延机的结构参数说明.2.PLC的介绍。3.PLC的选型方案设计。4.调速系统方案进行比较论证，包括主电路方案和控制回路方案。

关键词：四辊压延机，PLC，调速

Abstract

Is introduced in this paper the current situation of the development of the domestic four roll calender, and existing problems, and introduces the working principle of the programmable controller, selection basis. Design a kind of based on PLC automatic four roll calender, detailing the selection of Siemens S7-200 PLC and the same type of S7-300 S7-400PLC, according to the design requirements of input and output of the PLC I / O for the distribution, and the preparation of the ladder diagram of the system is running. Introduces the working principle, and the design of the circuit, and according to the DC motor has a good starting and braking performance, is suitable for the wide range speed smoothly, in many of the need for speed or fast forward and reverse drag in the field of electricity has been widely used. In the power electronic converter, the thyristor controlled device has been replaced by the power switch device, and the transformation technology is transformed into the pulse width modulation (PWM) by the phase control. However, DC drive control is more mature in theory and practice, and many industrial production machinery in our country is the use of DC drive control system, so it occupies a large proportion in industrial production.

The speed control system can be divided into different control systems according to different standards. However, from a certain point of view, it can be divided into the speed control system is generally divided into open loop speed control system and closed-loop speed control system. Open loop speed control system is simple in structure, easy to implement and easy to maintain, but its static and dynamic performance can not meet the requirements of production and control. The closed-loop control system can be a good solution to these problems, so it has been widely used in the actual production. Among them, the speed and current double closed-loop control of DC system is the best performance, the most widely used DC speed control system.

This course is designed to illustrate the design of the four roll calender system based on PLC.

The system is mainly about the specific structural parameters of 1 four roll calender that the introduction of.2.PLC. 3.PLC selection scheme design. 4 speed control system scheme for comparison, including the main circuit and control circuit scheme。

Keywords: four roll calender, PLC, speed