基于PLC的传送带多速度控制系统解读

摘 要

传送带是一种广泛应用于工业的传输设备，对其进行自动化的改造无疑将提高工业生产的效率和安全性并且将大大的节约人力资源。因其意义重大，对传送带的改造是多方面的而本文将主要介绍的是：基于西门子PLC的传送带多速度控制系统的设计。该系统的设计包括硬件设计和软件设计。其中硬件设计包括西门子PLC、变频器、异步电动机的外部电路的设计与安装；软件部分包括程序的设计与调试。

所设计系统最终能够通过PLC与变频器实现以下功能：(1)能对物品进行运送，速度可根据两物品之间的距离自动变换防止传送物品之间发生碰撞；（2）能够实现故障报警、状态指示、传送带带负载软启动等；（3）能够实现手动与自动状态切换，方便维护。该系统主要运用了西门子PLC、传感器、继电器、变频器等器件，利用PLC良好的自动控制性能，实现流水线传送带传送过程的无人控制。本文将主要对PLC、变频器以及PLC对变频器的控制部分进行介绍。

关 键 词： 西门子S7-200 PLC 传送带 变频器 无人控制 VVVF

ABSTRACT

The conveyor belt is a widely used in industrial transmission equipment.Its automated transformation will undoubtedly improve the efficiency and safety of industrial production and will greatly save human resources.The transformation of the conveyor belt is a wide range.This article will focus on Siemens PLC based conveyor speed control system design. The design of the system including hardware and software design.The part of Hardware design, including design and installation of Siemens PLC, inverter, induction motor external circuit; The software part includes the design and debugging of the program.

Designed system useing PLC and VVVF will eventually be able to the following functions: (1) delivery of the workpiece, Speed can automatically change according to the distance between the two workpiece to prevent a collision between the workpiece; (2) to achieve fault alarm status indication, the conveyor belt to load boot prompt, loadthe soft-start; (3) can be achieved manually reset. The system is mainly used Siemens PLC, sensors, relays, inverter and other devices. PLC automatic control performance, no control of the assembly line conveyor belttransfer process.The article will introduce the PLC,inverter and how PLC control the conveyor.

Keywords: Siemens S7-200 PLC conveyor inverter automated VVVF

目 录

第一章 绪论········································································1 1.1 传送机的简介···············································································1 1.2 可编程逻辑控制器（PLC）····························································2 1.3 变频器············································································4 第二章 设计方案····································································7 2.1系统功能·····································································7 2.2方案设计·····································································7 第三章 系统的硬件设计····································································9 3.1主电路的设计····································································9 3.2 PLC的选择及硬件的设计····························································11 3.3电动机的选择·········································································13 3.4变频器的选择·········································································13 3.4.1变频器容量的选择································································13 3.4.2 MM440变频器的安装与调试·····················································13 3.5 传感器··················································································18 3.5.1 压力开关··············································································18 3.5.2 测距传感器············································································18 第四章 系统的软件设计························································20 4.1 STEP7-Micro/WIN软件·························································20 4.2 系统梯形图程序·····································································20 第五章 仿真·····································································27 谢辞··············································································33 参考文献··············································································34

大连交通大学2012届本科生毕业设计

第一章 绪论

现代工业往往追求高效率低成本，目前我国正处于经济发展的转型期并且随着科技的不断发展，未来工厂的生产过程必定会越来越智能化。传送带是一种物料传输设备，因其高效、连续、快速的特性，被广泛的应用于矿业、化工、机械、电力、建材、轻工业以及港口码头等重要的工业领域。也正因为传送带的应用十分的广泛，对传送带的制造和自动化改进对于工业生产的意义日趋重大。PLC自诞生起便广受业界的关注，如今PLC依然是自动控制领域的一大支柱。传送带和PLC的结合为大势所趋，未来必将大放异彩。

传统的传送带系统往往只能工作在某一固定的速度上，这种设计有着其他系统无法比拟的优点。那就是系统及其简单，操作简便易于掌握使用且用途广泛。其缺点也同样明显，当传送带上传送物品为易碎品或某些危险品时，若出口处有传送物品积压如果操作不当必然会造成损失甚至发生危险。传统传送带虽然可以加入自动停止功能，但反复的启停势必对电动机产生不良影响并且会影响物品传输时的稳定性。基于对单一速度传送带存在以上问题，一种多速度控制系统的概念被提出。本文即阐述了基于PLC的传送带多速度控制系统的一种设计方案。在介绍本系统之前我们先了解一下系统的各个主要组成部分。

1．1 传送机的简介

17世纪中叶，美国人开始应用一种架空的索道来传送散状的物料，所谓的传送带自此诞生；进入19世纪中后期，经过了近两个世纪的发展，各种现代结构的传送带输送机相继出现。 1868年，在英国出现了皮带式传送带的输送机；1887年，在美国出现了螺旋式的输送机；20世纪后，1905年，在瑞士出现了钢带式输送机；1906年，在英国和德国出现了惯性输送机。至此现代意义的传送带基本成型并且在此后传送带输送机 受到机械制造、化工、电机、电子和冶金工业技术进步的影响，不断完善，逐步由完成车间内部的传送，发展到完成在企业内部、企业之间甚至城市之间的物料搬运。时至今日传送带已然成为物料搬运系统机械化和自动化不可缺少的重要组成部分。现代工业生产过程中，因传送带应用之广泛、工作之可靠相信在未来相当一段时间内其地位无可动摇。

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