恒压供水变频调速系统的设计毕业论文.doc

题目：恒压供水变频调速系统的设计 摘 要 本系统采用PLC进行逻辑控制，采用带PID功能的变频器进行压力调节，系统存在工作可靠，使用方便，压力稳定，无冲击等优越性。通过PLC、变频器、继电器、接触器控制水泵机组运行状态,实现管网的恒压变流量供水要求。设备运行时,压力传感器不断将管网水压信号变换成电信号送入PLC,经PLC运算处理后,获得最佳控制参数,通过变频器和继电器控制元件自动调整水泵机组高效率地运行。供水系统的监控主要包括水泵的自动启停控制、供水压力的测量与调节、系统主管道水压的；系统水处理设备运转的监视、控制；故障及异常状况的报警等。现场监控站内的控制器按预先编制的软件程序来满足自动控制的要求，即根据供水管的高/低水压位信号来控制水泵的启/停及进水控制阀的开关，并且进行溢水和枯水的预警等。 关键词:变频调速；传感器；恒压供水 Abstract The system uses PLC logic control inverter with PID function of pressure regulator, the system is reliable, easy to use, stable pressure, the impact of superiority. PLC, inverter, relay, contactor control the running state of the pump unit, the constant pressure variable flow water pipe network. Equipment run-time, pressure sensors keep the pipe network water pressure signal transform into an electrical signal into the PLC, the best control parameters after PLC computing, through the inverter and relay control elements automatically adjust the pump unit efficiently run. Monitoring of the water supply system including the pump automatic start and stop control, measurement and adjustment of water pressure, water pressure of the system in charge of Road; functioning surveillance system, water treatment equipment, control; failure and abnormal state of alarm. Site monitoring station controller according to the pre-preparation software programs to meet the requirements of the automatic control, water pipes, high / low pressure signal to control pump start / stop and water control valves, switches, and carry overflow and the early warning of low water. Keywords: frequency conversion；sensorconst；ant pressure water supply 目 录 摘 要 Ⅰ Abstract Ⅱ 1 前 言 1 1.1 供水系统发展过程及现状 1 1.2 供水系统的概述 1 1.2.1 变频恒压供水系统主要特点 1 1.2.2 传统定压方式的弊病 1 1.2.3 恒压供水设备的主要应用场合 2 1.2.4 恒压供水技术实 2 2 系统总体设计方案 4 2.1系统控制要求 4 2.2方案的比较 4 2.2.1 控制方案 4 2.2.2 运行特征 5 2.2.3 系统方案的拟定 5 2.2.4 系统方案的比较 6 3 主电路 8 3.1系统主接线图 8 3.2 主电路中器件的选择 8 3.2.1 低压断路器 8 3.2.2 低压熔断器 9 3.2.3 热继电器 9 3.2.4 交流接触器 10 3.2.5 电动机的调速原理及选型 10 4