（毕业设计论文）《PLC控制的变频调速恒压供水系统》.doc

PAGE 内蒙古科技大学 本科生毕业设计说明书（毕业论文） 题 目：PLC 控制的变频调速恒压供水 系统 学生姓名： 学 号： 专 业：电气工程及其自动化 班 级：电气 指导教师： 讲师 PLC控制的变频调速恒压供水系统 摘要 由于传统供水方式的缺陷，本文设计了一套PLC控制的变频调速恒压供水系统。 恒压供水是指在供水网系中用水量发生变化时，出口压力保持不变的供水方式。系统由可编程控制器、变频器、水泵电机组、远传压力表等构成。共三台电机，其中由一台变频器拖动2台大功率电动机的起动、运行与调速，1台小容量电机备用。控制系统中采用德国SIMENS公司的S7-300可编程控制器来控制水泵电机的投入台数及运行方式；同时利用其中的数字PID控制器，由SFB41将压力给定值与测量值的偏差进行处理，实时控制变频器的输出电压和频率，进而改变水泵电动机的转速来改变水泵出水口流量，实现管网压力的自动调节，使管网压力稳定在设定值附近。 关键词： PLC；变频调速；恒压供水 PLC control of the Frequency Control Water Supply System Abstract Because the flaw of the tradition water supply system, I designed a PLC control of the Frequency Control Water Supply System. Constant pressure water-supply means that the water supply networks in the event of changeable water consumption, but the exports still remain the same pressure. The component of this system includes the PLC, Drives, pump motor group, and the pressure sensor. This design uses one transducer drivers 2 Motors starting, running and speed control. Another small capacity motor is used to be reserved. The control system used S7-300 programmable controller which be made in Germany SIMENS corporation. Through the PID controllers, pressure will be given the fixed value and processing error of the measurement by SFB41. Using the controllers to control the voltage and frequency of the frequency converter in real-time and then change the pump motor Speed to change the pump outlet flow, the pressure on the pipe network to achieve automatic adjustment so that the pressure pipeline network settings stability in the vicinity. Key words: PLC; constant pressure water-supply ; variable frequency speed-regulating 目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc201832698 摘要 PAGEREF _Toc201832698 \h I HYPERLINK \l _Toc201832699 Abstract PAGEREF _Toc201832699 \h II HYPERLINK \l _Toc201832700 第一章 引言 PAGEREF _Toc201832700 \h 1 HYPERLINK \l _Toc201832701 1.1 课题提出的背景 PAGEREF _Toc201832701 \h 1 HYPERLINK \l _Toc201832702 1.2 课题研究的目的和意义