基于SH-7_PLC多功能变频恒压供水控制系统设计_毕业设计论文.doc

基于SH-7_PLC多功能变频恒压供水控制系统设计 摘 要 随着社会经济的飞速发展，城市建设规模的不断扩大，人口的增多以及人们生活水平的不断提高，对城市供水的数量、质量、稳定性提出了越来越高的要求本系统详细介绍了用于工民建,生产用水中的变频恒压供水控制系统,它主要由变频器,PLC,压力传感器,调节器,接触器等组成,并对其工作原理做了详细解释, 本设计包含先进的给水方案，自动控制技术，变频调速技术（VVVF无级调速）及先进的过程控制技术，实现了恒压供水的参数设定定，PID自动控制，保证了供水系统工作于最佳运行工况，保证在实际中可以提供高质量的供水服务.变频调速恒压供水技术其节能、安全、供水高品质等优点，在供水行业得到了广泛应用。 本设计是针对居民生活用水/消防用水而设计的,由变频器、PLC及PID调节器组成控制系统，调节水泵的输出流量。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。 本文介绍了采用PLC控制的变频调速供水系统，由PLC进行逻辑控制，由变频器进行压力调节。在经过PID运算，通过PLC控制变频与工频切换，实现闭环自动调节恒压供水 恒压供水系统依据用水量的变化（实际上为供水管网的压力变化），实现电机的自动运行,切换等工作方式.在用水量发生变化时保持水压恒定以满足用水要求是现在先进、合理的节能型供水系统。在实际应用中充分利用变频恒压调速的各种功能，对合理设计和使用变频器调速恒压供水设备,降低成本、提高可靠性,保证产品质量以及节约水资源等有着重要意义。 关键字：变频恒压供水,?继电接触,PID调节,节能高效 ABSTRACT With the rapid socio-economic development, urban construction expanding the size of the population increase, as well as the continuous improvement of living standards of urban water supply quantity, quality, stability, made ever-increasing demands of the system described in detail for buildings for , production of water in the frequency control constant pressure water supply system, which is mainly by the frequency converter, PLC, pressure sensor, regulator, such as exposure to the composition and working principle of a detailed explanation, the design program includes advanced water supply, automatic control technology, variable frequency speed control technology (VVVF stepless speed regulation) and advanced process control technology, to achieve a constant pressure water supply set of parameters, PID automatic control, to ensure the water supply system in the best operating conditions to ensure that in practice can provide high-quality water supply services. VVVF constant pressure water supply of its energy-saving technology, security, high-quality water supply, etc., in the water supply industry has been widely applied. It is very important of the Water Supply System in Constant Pressure for the water supply in industrial and citizen existence. It is