Fuzzy Predictive Control Of The Constant Pressure Water Supply System With Freouency Conversion

In real life, the traditional way of water supply have reached the purpose of water supply, but there are a lot of problems, such as the low degree of automation, hydraulic waste of resources, the low performance of reliability and stability. The develop of the current water supply system is toward to the direction of high efficiency and conservation energy, automation and reliable. The technology of variable frequency variable velocity characteristics of a significant effect of conservation energy and a reliable control methods, it has been widely used in high-energy consumption equipment, such as fans, pumps. Particularly in the residential water of the water supply system, the technology of variable frequency variable velocity used in pumps has a significant effect of conservation energy.The constant pressure water supply system has the characteristics of nonlinearity, uncertainty, delay and so, this paper intends to research water supply system based on FPC with the variable frequency variable velocity and constant pressure.Fuzzy Control and Predictive Control are the effective ways to control systems about time-varying, non-linearity, large hysteresis and uncertain. Fuzzy Predictive Control is the integrated control algorithm based on the typical algorithm of predictive control and fuzzy control theory. The technology of Fuzzy predictive control (FPC) has been used in the system which under study in this paper, allowing the system to get a very good energy efficiency, at the same time, the stability of the system has also been greatly improved, and so to study the subject has a certain degree of practical significance to ensure that people’s daily life and industrial about the water.This thesis is mainly designed a set of system of constant pressure water supply by using variable frequency variable velocity and remote monitoring and controlling, which is composed of PLC, transducer, pressure transmitter, pumps and electro-motors, computer and device of communication. The control objective is to achieve the pressure of water about the pipe network of export to follow the set pressure of the water supply, that is to maintain constant about the pressure of water. Through the analysis of the control structure of the system to account the approximate mathematical model of the system, complete the hardware design of the system, including the design of the main circuit and control circuit, select the configuration of the hardware used about the system, complete the Software design of the system, including the design of the control program of PLC, but also in the design of the entire system, it has been considered the anti-jamming, and given the appropriate measures. When the system is failure, it has the processing functions of emergency to ensure operational stability. Combined with PID control algorithm, through the communication protocol between the computer and PLC, debug the system, completed the communication settings about the host computer and lower machine, given the computer monitor programming, through the communication module to achieve function about monitor of long rang and alarm of fault in the water supply system. And analysis the basic principles of three different controllers (PID controller, fuzzy controller, fuzzy predictive self-tuning PID controller), designed fuzzy predictive self-tuning PID controller to overcome the problem about the difficult of parameter adjustment in the traditional control algorithm. At the same time, used the SIMULINK toolbox of MATLAB to test the traditional PID control algorithm, the fuzzy control algorithms, and this fuzzy predictive control algorithm for the simulation, and the results of the simulation test were analyzed. Which shows the fuzzy predictive self-tuning PID control method has a strong ability to adapt to environment change and improve the robustness of the control systern.the controller can regulate automatically in random environment. making when the characteristics of controlled object in the case of change or disturbance, control system can maintain a good performance. Enhanced anti-jamming capability of the system, making the system has better dynamic characteristics and ideal steady-state quality.