基于PLC的恒压供水控制系统的设计-毕业论文.doc

毕业设计（论文） 毕业论文题目：基于PLC的恒压供水控制系统的设计 PAGE IV 摘 要 随着城市化的发展，供水的便利性和稳定性决定了用水的品质，对工作和生活有着重要的意义。本文设计的变频调速恒压供水系统是以PLC以及频率转换器为主要控制系统，A/D转换模块将压力传感器检测到的数字信号变成标准的电信号，通过CPU的PID算法处理的差异，然后由CPU发出控制指令，改变频率可变控制器的频率和输出电压来改变泵的转速和泵数，比如一台作变速运行时其他两泵作恒速运行。这样，主管道的压力就稳定在恒定范围内，从而保证了供水能力与用水的平衡。此外，变频恒压供水是以PLC为基础，并与供水泵、压力表等设备相结合，实现切换水泵、运行监控、数据报警的功能。 供水系统以用户体积为基础，自动调节参数的节能系统实现了水量的恒定和多变。该系统能保持稳定的水压，保护需水量，可应用于高层建筑、居民小区、企业生产等方面。 关键词：PLC；恒压供水；变频调速；组态软件 ABSTRACT The A / D conversion module changes the digital signal detected by the pressure sensor into the standard electrical signal, processes the difference through the PID algorithm of the CPU, and then the CPU sends out the control command, changes the frequency and output voltage of the frequency variable controller to change the speed and number of pumps, such as The other two pumps operate at constant speed when the platform is in variable speed operation. In this way, the pressure of the main pipeline is stable in a constant range, thus ensuring the balance between water supply capacity and water consumption. In addition, frequency conversion constant pressure water supply is based on PLC, and combined with water supply pump, pressure gauge and other equipment, to achieve the function of switching water pump, operation monitoring, data alarm. The water supply system is based on the user volume, and the energy-saving system with automatic adjustment parameters realizes the constant and variable water volume. The system can maintain stable water pressure and protect water demand, which can be applied to high-rise buildings, residential areas, enterprise production and other aspects. Key words: PLC; constant pressure water supply; variable frequency speed regulation; configuration software 目 录 TOC \o 1-5 \h \z \u 1绪论 1 1.1 引言 1 1.2 课题背景及意义 1 1.3 供水系统的国内外研究现状 2 1.3.1 国内外发展与现状 2 1.3.2变频供水系统的发展趋势 2 1.4 PLC概述 3 1.4.1 可编程逻辑控制器简介 3 1.4.2 西门子S7-200系列PLC简介 3 2 变频恒压供水系统的理论分析及方案 5 2.1 系统的理论分析 5 2.1.1水泵工作原理及节能原理 5