基于PLC小区变频恒压供水系统.doc

摘要 I 摘要随着社会主义市场经济的发展,人们对供水质量和供水系统可靠性的要求不断提高;加上目前能源紧缺,利用先进的自动化技术、控制技术以及通讯技术,设计出具有高性能、高节能、能适应不同领域的恒压供水系统成为必然的趋势。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、压力传感器等构成。本系统包含 3台水泵电机,它们组成变频循环运行方式。采用变频器实现对水泵电机的软启动和变频调速。压力传感器检测当前水压信号,送入变频器与设定值比较后进行 PID 运算,改变变频器的输出频率调节水泵电机的转速;压力信号与工频变频的切换信号同时送入 PLC 中, 通过变频泵循坏方式来调节总供水量,使管网压力稳定在设定值。本设计完成了系统的硬件设计,包括电器元件的选型以及系统电路的设计;完成系统的软件设计,包括系统流程图的设计与系统程序的设计。关键词变频调速恒压供水 PLC 燕山大学本科生毕业设计(论文) II Abstract With the development of the socialist market economy , people's water quality and reliability requirements and continuously improve the water supply system ; coupled with the current energy shortage , the use of advanced automation technology , control technology munication technology , design a high-performance , high-energy , able to adapt to different areas of water supply systems has e an inevitable trend 。 According to China's urban residential water requirements , design a PLC-based frequency control water supply system 。 Constant pressure water supply system consists ofa programmable controller , inverter , water pumps , pressure sensors 。 The system includes three pump motor , they form the loop variable frequency operation mode 。 Inverter is used to achieve the pump motor soft-start and frequency control 。 Hydraulic pressure sensor detects the current signal into the PID operation after pared with the inverter , change the output frequency of the inverter to adjust the pump motor speed ; pressure signal with frequency inverter switching signals are simultaneously sent to the PLC via pump-way through the bad to adjust the total amount of water , the work pressure stabilized at the set value 。 plete design of the hardware design of the system , including the selection of the ponents of the circuit and system design ; complete system software design , including the design of the system design and system flow chart of the program 。 Keywords Variable frequency speed-regulating Constant-pressure water supply PLC III 目录摘要.