毕业设计（论文）-PLC变频调速恒压供水系统.docVIP

摘 要 本文介绍一种变频调速恒压供水系统，该系统能够根据运行负荷的变化自动调节供水系统水泵的数量和转速，使整个系统始终保持高效节能的最佳状态。文中详细介绍了系统的控制原理及硬件电路恒压供水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，进行优化控制泵组的调速运行，并自动调整泵组的运行台数，完成供水压力的闭环控制，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，其差值输入运算处理后，出， 关键词： 变频器???恒压供水系统???PID；????PLC Abstract This?paper?introduces?a?constant?pressure?water?supple?system.?It?can?regulate?aut-omatically?the?quantity?and?rotational?speed?of?the?water?pump?with?the?variation?of?the?load.?The?controlling?principle?and?the?hardware?circuit?are?presented?in?detail. The basic control strategy of the control system of constant pressure of water supply is: install the control system with motor speed adjustment and programmable logic controller (PLC), it carries out optimization control pump organization of the operation of speed adjustment, and adjusts the number of running pumps, completes pressure of water supply closed-loop control system, reaches the steady pressure of water supply in the changing of rate of flow in the pipe net and the purpose of economizing electrical energy. The control goal of system is the effluent pressure of pump station. Comparing the pressure of system setting and the actual hydraulic pressure coming from feed backed water supply control system, the comparing result inputs the PID regulator which has pressure show, after handling the result, exports analogy signal to the inverter, then using the inverter of the two programmable relay exports RO1 and RO2 to give PLC signal, so PLC judges whether add pump or cut pump. Compared realizing the constant pressure water supply with inverter with realizing the constant pressure water supply with adjustable valve, the effect of energy saving is very notable. The systems advantage is that starting steadily, the starting current may be restricted within specified current, so avoided the impact of electrical network when it starts; because the average rotational speed of pump is reduced, may prolong the using of pump a