基于PLC和变频器的恒压供水系统

Constant Pressure Water Supply System Besed on PLC & Inverters

恒压供水系统用可编程序控制器进行逻辑控制,采用变频器进行压力调节,变频器、可编程序控制器作为系统控制的核心部件。时刻跟踪管网压力与给定压力的偏差变化,经变频器内部自适应PID运算,通过可编程控制器控制变频与工频切换,自动控制水泵投入的台数和电机转速,实现闭环自动调节恒压变量供水,在保持恒压下控制流量。运行结果表明,该系统具有压力稳定、结构简单、工作可靠等特点。

Constant pressure water supply system uses programmable logic controller （PLC） to process the logic control and employed frequency converter to adjust water pressure.Frequency converter and PLC are the key components of system control.They follow up the deviation between the pipe network pressure and pressure given.Through operation of PID and switchover of frequency conversion and main frequency was controlled by PLC,it could automatically control numbers of water pump put into operation and speed of AC motor for realizing automatic regulation of close-loop and suppling water under constant pressure and variable runoff.The results indicated,it has lots of advantages with pressure constant,structure simple and operation reliable etc.