Research And Development Of The Constant Pressure Water Supply Control System Without Tower Based On PLC

People’s normal work and life are directly affected by water supply system in the building, which have some characteristics, such as reliability, economy, stability. The operators and consumers are also in the pursuit of efficient utilization and effective management of water resources. With the development of the secondary water supply pressure technology, the constant pressure water supply system without tower is combined with the no tower device and frequency control of motor speed, and the microcomputer control technology is applied to automatic control of pump unit. The water supply system not only achieves high efficiency and energy saving, but safe and reliable. Main contents of this thesis are as follows:Firstly, the constant pressure water supply system without tower model is set up and the main hardware components required for water su pply system is configured. The energy saving principle of the constant pressure water supply system without tower is analyzed. The pump cycle and the switching condition of the constant pressure water supply system is determined.Secondly, the main circuit and control circuit of control system is determined. Hardware configuration and control programming of the water supply control system is completed in STEP 7, which is simulated in the PLCSIM. Then the PID principle is analyzed to realize automatic constant pressure water supply function.Thirdly, according to the basic theory of fuzzy PID control, the control rules are set in fuzzy reasoning way and fuzzy PID controller was designed. Then the mathematical model of the water system is established. The simulation result of fuzzy PID control and conventional PID control for the water supply system are compared by using MATLAB Simulink module.Finally, HMI man-machine interactive interface is designed by Win CC configuration software, which can monitor and manage the field running equipment. Thus the functions of real-time data acquisition, equipment control, parameter adjustment and all kinds of signal’s alarming, filing are achieved.