继电接触式变频恒压供水控制系统设计_毕业设计.docVIP

继电接触式变频恒压供水控制系统设计 摘 要 供水工程往往成为高层建筑或工矿企业和小型企业中最重要的基础设施之一。任何时候都能提供足够的水量、平稳的水压、合格的水质是对给水系统提出的基本要求。本系统研究了变频调速技术在民用建筑供水系统中的应用，采用继电接触式控制系统和变频器作为主控单元，配合接触器，PID调节器，压力传感器，干簧管等构成了变频供水的智能控制系统。其中为了节约成本采用继电接触式对系统进行逻辑控制，变频器进行压力调节，压力传感器时刻跟踪水泵出口压力和给定压力值的偏差变化，经PID调节器内部运算送入变频器，由控制电路控制3台电机的起停以及工频与变频的切换，实现闭环自动调节恒压变频供水，在保持恒压的前提下达到控制流量的目的。充分发挥了变频调速的优势，具有高效节能，自动控制，性能稳定的优点。 关键词：继电器，接触器，变频调速，恒压供水 ABSTRACT The water supply project often becomes one of most important infrastructures in the high-rise construction or the Industrial and mining establishment and the Small businesses. Providing the enough water volume at any time, the steady hydraulic pressure, the qualified water quality is the essential requirements which proposed to the aqueous system. This system has studied the frequency conversion velocity modulation technology in the civil construction water supply systems application, using relay and contractor control system and the frequency changer, coordinates the contact device, the PID regulator, the pressure transmitter, reed pipes and so on to constitute the frequency conversion water supply intelligent control system. And to save the cost ,It uses relay and contractor to finish the logical control, the frequency changer to finish the pressure control, the pressure transmitter time track water pump outlet pressure and assigns the value of pressure the deviation change, sends in the frequency changer after the PID regulator internal arithmetic, controls 3 electrical machinery by the control circuit to stop as well as the power frequency and the frequency conversion cut, realizes the closed loop automatic control constant pressure frequency conversion water supply, maintains the constant pressure the premise issues the control current capacity the goal.This system has fully displayed the advantage of Vaviable frequency Control, has the excellence of energy conservation, automatic control, stable property merit. KEY WORDS: Relay, Contacor, Vaviable frequency Control, Constant pr