摘要

目前国内研究供水系统的行业仍然处于发展的初级阶段，在市政供水、工业供水等方面技术比较落后。随着我国社会主义市场经济的发展，国民生活水平不断提高，城市高层住户也逐渐增多，人们对基础设施的建设提出更高的要求。小区供水系统的建设是其中的一个重要方面，除了要保证供水质量和供水系统可靠性，还要具有稳定、节能、自动化程度高等优点。因此，设计一套基于PLC和变频器的恒压供水系统，根据系统状态快速调整供水量，有一定的现实意义。

PLC作为主控制器进行逻辑控制，变频器作为执行机构进行压力调节，然后用PID对系统中的恒压控制进行设计；PLC控制变频与工频切换，实现闭环自动调节恒压供水，该系统具有高度的可靠性和实时性，具有明显的经济效益和社会效益。

与传统供水方式相比，该系统在稳定性、可靠性、自动化程度等方面都有很大的优势，而且还具有明显的节能效果。早期的单泵恒压系统正逐渐被多泵系统代替，由此可见基于PLC和变频器的恒压供水系统的设计是必要的。

关键词：PLC;变频器；恒压供水；PID

Abstract

At present, the domestic water supply industry is still in the primary stage of development, and the technology of municipal water supply and industrial water supply is relatively backward. With the development of China's socialist market economy and the continuous improvement of people's living standards, the number of high-rise urban households is also increasing. People put forward higher requirements for infrastructure construction. The construction of community water supply system is one of the important aspects. In addition to ensuring the quality and reliability of water supply system, it also has the advantages of stability, energy saving and high degree of automation. Therefore, it has practical significance to design a set of constant pressure water supply system based on PLC and frequency converter, and quickly adjust the water supply according to the system status.

PLC is used as the main controller for logic control, frequency converter as the actuator for pressure regulation, and then PID is used to design the constant pressure control in the system; PLC controls frequency conversion and power frequency switching to realize closed-loop automatic regulation of constant pressure water supply, the system has a high degree of reliability and timeliness, with obvious economic and social benefits.

Compared with the traditional way of water supply, the system has great advantages in stability, reliability, automation and so on, and also has obvious energy-saving effect. Early single pump constant pressure system is gradually replaced by multi pump system, so it is necessary to design constant pressure water supply system based on PLC and frequency converter.

Key word: PLC; frequency converter; constant pressure water supply; PID