下载后可任意编辑摘 要本论文根据中国城市小区的供水要求，设计了一套基于PLC的变频调速恒压供水系统。变频恒压供水系统由可编程控制器、变频器、水泵机组、压力变送器等构成。本系统包含三台水泵电机，它们组成变频循环运行方式。采纳变频器实现对三相水泵电机的软启动和变频调速，运行切换采纳“先启先停”的原则。压力变送器检测当前水压信号，送入PLC与设定值比较后进行PID 运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速来改变供水量，最终保持管网压力稳定在设定值附近。并且通过PLC实现报警控制。关键词：变频调速，恒压供水，PLC- I -下载后可任意编辑ABSTRACTThis paper according to the requirements of the water supply of China's urban district, designed a set of variable frequency speed regulation based on PLC of constant pressure water supply system. Frequency conversion constant pressure water supply system by PLC, frequency converter, pump unit, pressure transmitter, etc. This system includes three pump motor, they constitute frequency conversion cycle operation mode. The frequency converter to realize the three-phase pump motor soft start-up and frequency control, run by switching "first rev. First stop" principle. Pressure transmitter detection current water pressure signal, into PLC and setting after comparison PID operation, so as to control the output voltage and frequency converter, and change the water pump motor speed to change water supply, eventually, keep the pipe pressure stable value in nearby. And through the PLC alarm control.Keywords: Frequency control, constant pressure water supply, PLC- II -下载后可任意编辑目 录1 绪 论 ...........................................................................................................................11.1 课题的提出..........................................................................................11.2 变频恒压供水系统的国内外讨论现状..........21.2.1 变频恒压供水系统...
