摘要众所周知，交流电机的适应性很高、维修简单、容易实现快速化及大容量化、价格实惠，所以交流电机变频调速会逐渐占领之前直流电机占重要地位调速传动领域。交流电机变频调速在调速精度、输出性能、频率范围、动态响应、方便使用、功率因数、工作效率、低频转矩等方面是之前交流调速方式所不能比拟的，它的优越性主要体现在两个方面:一是卓越的调速性能；二是节电显著。本文在传统应用变频器进行变频调速基础上，通过几种PLC和变频器的对比，最后决定采用三菱FX2NPLC来控制变频器（三菱FR-S540）对交流电机的启动、停止、平滑的调速，从而达到远程控制调速更加简便实用的要求。本设计采用触摸屏来给定输入转速，减少了PLC 的外部I/ O 点使用和减轻了系统外部按钮开关连线复杂的程度,同时增强了运行维护方便性。

采用V/F控制方式，PLC中的PID调节和增量式旋转编码器反馈控制，实现对三相交流异步电动机的闭环运行控制。通过设计硬件电路和软件系统实现了电机的平滑调速，而且对结论进行了实践调试，系统的运行正常，于是达到了预期设计效果。70414

该设计有图20幅，表1个，参考文献27篇。

毕业论文关键字：变频调速  PLC控制  恒压频比控制

Design of AC variable frequency speed regulating system based on PLC

Abstract    As we all known,the AC motor adaptability, easy maintenance, low price, easy to implement high-speed and large capacity, thus, before the DC motor speed transmission-dominated areas will gradually be the occupation of AC motor speed change. AC frequency control in the frequency range, dynamic response, speed precision, low torque, output performance, power factor, efficiency, ease of use and so is the way the past can not compare speed of communication.

In this paper, the traditional application of the inverter frequency control based on the programmable controller and drive through several contrast, the last with Mitsubishi PLC (FX2N) programmable logic controller to control the drive (Mitsubishi FR-S540 ) of AC motor starting, stopping and smooth speed control, remote control speed to achieve a more simple and practical purposes. The touch-screen design application given input speed, reducing the external PLC I/O points and reduce the use of an external button to switch the connection system complexity, while improving the ease of operation and maintenance. 

    Application of V/F control, PLC programmable controller PID regulator and incremental rotary encoder feedback control to achieve the control object (three-phase AC induction motor) closed-loop operation control. Through the hardware and software systems design and implementation of the smooth speed of the motor, and the conclusion of the commissioning, the system operating normally, to the design of the desired effect. 

    The design has 20 figures , 1 table, 27 references.

Key Words:  Variable speed constant  PLC controlled  Frequency ratio control 

目 录

摘要 I

Abstract II

目录 III

图清单 Ⅴ

表清单 Ⅵ

变量注释表 Ⅵ

1 绪论 1

1.1 本课题的研究背景及意义 1

1.2 电机调速发展现状及应用前景 2

1.3 本设计主要内容 2

2 关于交流电机的变频调速原理