大学毕业论文—基于plc的恒压供水控制系统设计.doc

编号 毕业论文 题 目 基于PLC的恒压供水控制系统设计 学生姓名 学 号 系 部 电气工程系 专 业 电气自动化技术 班 级 指导教师 顾问教师 二〇一四年十一月摘 要 随着社会经济的迅速发展，人们对供水质量和供水系统可靠性的要求不断提高，再加上目前能源紧缺，利用先进的自动化技术、控制技术以及通讯技术，设计高性能、高节能、能适应不同领域的恒压供水系统成为必然趋势。 在城市建筑逐步向高层化发展的今天，生活用水、消防用水等对供水配套装置提出了更高的要求。变频调速恒压供水设备采用国际上成熟的变频调速技术，具有水压稳定、维护方便、运行费用低、节能等优点。 本设计是针对居民生活用水和消防用水而设计的恒压供水变频调速系统。本系统以PLC为控制核心，结合变频调速技术、PID控制技术设计，将压力传感器采集的信号作为PLC的控制信号，由PLC完成PID的算法，将PID的输出作为变频器的频率控制信号，达到恒压供水的目的。本系统的电动机泵组由三台水泵并联而成，由变频器或工频电网供电，根据供水系统出口水压和流量来控制变频器电动机泵组之间的切换及速度，使系统运行在最合理的状态，保证按需供水。运行结果表明，该系统具有压力稳定，结构简单，工作可靠等优点。 关键词：PLC 变频器 恒压供水 控制系统 Abstract With the rapid development of social economy, peoples requirements on the quality and reliability of water supply system continues to improve, coupled with the current severe energy shortage, the use of automation technology, control technology and communication technology, advanced design, high performance, high energy saving, can adapt to different field of constant pressure water supply system has become an inevitable trend. In the city building gradually to the high level of development today, the living water, fire water etc. to put forward higher requirements for water supply supporting device. Variable frequency speed constant pressure water supply equipment using the mature of variable frequency speed regulation technology on international, with advantages of stable water pressure, convenient maintenance, low operating cost, energy saving etc.. The design of frequency control constant pressure water supply system is designed for the residents living water and fire water. This system takes PLC as the control core, combined with the technical design of PID control technology of frequency control, signal acquisition, the pressure sensor as the PLC control signal, PID algorithm is completed by the PLC, the PID output as the frequency converter control signal, constant pressure water supply to achie