Jiujiang University Water Supply System Frequency Conversion Constant Pressure Control Technology

With the rapid development of social economy, it demands the better of water supply's quality and reliability of water supply system. Meanwhile energy resources are seriously lack. So it is inevitable tendency to design water supply system which has high function and saves on energy well, with help of advanced technique of automation, control and communication. At the same time this system can adapt different water supply fields.This paper explains wter supply system's energy-saving principle of pump VF speed control according to characteristic curve of running pipelines and water pump, analyzes the structure of VF speed regulating constant pressure water supply. In this paper, on the basis of above PLC and inverter's method fits water supply system and data transmission very well. Then constant pressure supply water controller is designed by fuzzy-PID control respectively, and the design of the system's hardware and soften is introduced.There are some drawbacks such as conversion current is great, easy to burn the fuse and switch if off in variable frequency to working frequency of high-power electromotor. In the former researching, the conversion of variable frequency to working frequency is only emphasized the speediness. The conversion is usually failed because the key is not the speediness of conversion. Through analyzing and researching the problem of variable frequency to working frequency of high-power electromotor in theory, the key of conversion is pointed out in the paper. On the basis of analyzing vector-diagram of induction-motor, the phase of working frequency power whether or not consistent with the output phase of variable frequency power at the moment of conversion is the key to decide whether the conversion is successfully. With the application of phase detector in this system, It is succeed to solve the problem of variable frequency to working frequency and realizing the smooth conversion of high-power electromotor.This article establish the frame of pumping station supervisory system based on "King View", and propose the project to develop the distributed control system of pumping station using "King View" as supervisory software and Siemens S7-200 as hypogynous machine. It can collect signal automatically,...