恒压变频供水控制系统的设计.doc

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、压力传感器、工控机等构成。 ABSTRACT According to the requirement of Chinas urban water supply, this paper designs a set of water supply system of frequecey control of constant voltage based on PLC, The system is made up of PLC, transducer,units of pumps,pressure sensor and control machine and so on. The design of the system is the VF water supply systems that controlled by PLCof Siemens S7-200 series. The paper introduced the principle of energy saving,system structure and working principle of this control system. By the logic control of PLC, pressure adjustment of the frequency converter, operation of PID, PLC controls the switchover between variable frequency and power frequency, which automatically makes the closed-loop adjust constant pressure and conduct the variable water supply. Of the system design, it gives a comprehensive introduction of hardware system configuration, selection, software system process design, and process design. It also points out the problems that existed in design process and gives the related solutions. Key words: PLC variable frequency speed-regulating constant-pressure water supply 目 录 摘 要 I ABSTRACT II 第1章 绪 论 1 1.1引 言 1 1.2恒压变频供水的意义 2 1.3恒压变频供水的现况 3 1.3.1恒压变频供水国内外的发展情况 3 1.3.2恒压变频供水的优点 4 1.3.3恒压变频供水系统应用范围 4 1.3.4恒压变频供水系统功能设计要求 4 第2章系统的理论分析与设计 6 2.1恒压变频供水的原理和方法 6 2.2电动机调速原理 7 2.3变频恒压供水的节能原理 7 2.4控制系统方案的设计与选择 9 2.5变频恒压供水系统的构成 10 2.6变频恒压供水的控制流程 12 第3章恒压变频供水的硬件设计 14 3.1 PLC的选型 14 3.1.1 PLC简介 14 3.1.2 PLC的选型 15 3.1.3 PLC的I/O口分配 16 3.2变频器的选型 17 3.2.1变频器简介 17 3.2.2变频器的选型 18 3.2.3变频器外围端口接线及功能 20 3.3压力变送器的选型 22 3.3.1压力变送器的作用 22 3.3.2压力变送器的选型 23 3.3.3压力变送器的接线 23 3.4水泵机组的选型 24 3.4.1水泵机组的选型原则 24 3.4.2水泵机组的选型 24 3.5系统硬件电路设计 25 3.5.1系统主电路设计 25 3.5.2系统控制电路要求 26 3.5.3系统控制电路设计 27 3.5.4系统控制指示电路设计 29 第4章恒压变频供水系统软件设计 30 4.1总体流程设计 30 4.11手动运行流程设计 30 4.12自动运行流程设计 32 4.2各个模块梯形图设计 35 4.21软原件设计 35 4.22手动控制程序设计 36 4.23自动控制程序设计 38 4.24初始化程序设计 41 4.3 PID控制器参数整定 45 4.31 PID控制及其算法 45 4.32 PID算法在S7-200