恒压供水系统PLC设计摘 要该毕业设计对环保、节能、自动补压型给水设备作了介绍。从节能科技的实践出发，阐述了变频调速技术在高楼给水设备中的应用。以PLC电路控制方式，介绍了智能水压控制系统的工作原理及PLC控制系统。在分析水压控制的工作流程的基础上，给出了PLC控制系统的硬件和软件设计。智能水压控制系统的基本控制策略是：采用电动机调速装置与可编程控制器（PLC）构成控制系统，进行优化控制,完成供水压力的恒定控制，在管网流量变化时达到稳定供水压力和节约电能的目的。系统的控制目标是泵站总管的出水压力，系统设定的给水压力值与反馈的总管压力实际值进行比较，其差值输入变频器运算处理后，发出控制指令，控制泵电动机的投运台数和运行变量泵电动机的转速，从而达到给水总管压力稳定在设定的压力值上。通过该项目的科研与应用，不仅能够节约宝贵的水资源、电资源，降低了生产成本，减少设备维护，降低维修成本，而且提高了整个水厂的生产调度管理水平，减轻工人劳动强度，有效的提高了生产率。关键字 恒压供水，PID控制，PLC,变频器ABSTRACTThe graduation design for environmental protection, energy saving, automatic pressure type water equipment are introduced. Starting from the practice of energy-saving technology, expounds the variable-frequency regulating speed technology application in building water supply equipment. With PLC control circuits, introduces the working principle of hydraulic control system and PLC control system. On the analysis of the working process of the hydraulic control based on PLC control system, presents the hardware and software design. The hydraulic control system, intelligent control strategy is: the basic motor speed device with programmable logic controller (PLC) control system, control, optimizing the constant pressure water supply pipe flow control, stabilize the supply pressure variation and saving energy. The control system is the main target pumping water pressure, the pressure of water supply system set value and practical value of the pressure feedback compared the poor input, processing operations, inverter control command, control pump powerstation sets and operation of motor pump motor speed, so as to achieve stable supply pressure in setting the manager on the pressure value.Through the research and application, we can not only save water and electricity the precious resources, reduce the production cost, reduce the maintenance of equipment, reduce maintenance cost, and increase the production scheduling of water level of management, reduce labor intensity, effectively improve the productivity.KEY WORDS the constant pressure water supply, PID control, PLC, frequency converter目 录摘要.IABSTRA.II第一章 前言.11.1设计恒压供水系统的意义.11.2 PLC与PID控制的应用现状.11.3本课题主要研究内容.31.4本章小结.3 第二章 系统的理论分析及方案的确定.4 2.1恒压供水系统的理论分析.42.1.1供水系统的基本特性.42.1.2机械循环液体管网的工作原理.42.1.3管网设定水压的水力计算.52.1.4 变频调速水泵电机节能的原理.62.1.5变频恒压控制的理论模型.82.1.6 变频恒压供水系统的近似数学模型.92.2 变频恒压供水系统控制方案的确定.92.2.1恒压供水系统的控制流程.92.2.2恒压供水系统中水泵切换条件分析.112.3恒压供水PID的研究.122.3.1 PID控制及控制算法.122.3.2恒压供水PID调节过程分析.142.4本章小结.15第三章 变频恒压供水系统的硬件设计.163.1变频恒压供水系统的基本构成.163.2变频恒压供水系统主要配置的选型.173.2.1水泵机组的选型.173.2.2 PLC系统选型.183.2.3变频器的选型.193.2.4压力变送器的选型.203.3控制系统的I/O点及地址分配.203.4系统的电气控制系统.213.4.1主电路图.213.4.2控制电路图.223.4.3 PLC系统外部接线图.233.4.4变频器外部接线图.253.5本章小结.25第四章 恒压供水系统的程序设计.264.1系统的程序结构说明及流程图.264.1.1主程序.264.1.2初始化子程序.284.1.3中断子程序.284.2 程序中使用的编程元件及其含义.294.3程序中关键程序段的梯形图及程序仿真.304.3.1泵站泵组程序.304.3.2故障诊断和报警输出程序.444.4本章小结.50第五章 结论.51致谢.52参考文献.53附录.