Constant Pressure Water Supply System Of Power Plant Control Application Research

With rapid development of our social economy and continuously improved living standard, more and more demands on water quality and the reliability of water supply system are put forword. Meanwhile, energy resources are becoming much scarce presently, energy saving and emission reduction has become the direction of all walks of life for technology improvement. So it is an inevitable tendency to design water supply system which has high function, high energy-saving, flexible operation, safe and reliable and high degree of automation with help of advanced industrial control technology. At the same time, this system can be applied to different water supply fields.Aiming to transformation requirements of Jiangsu Xutang power Co., Ltd deep well water system, a constant pressure water supply control system is designed that is controlled by PLC and drived by inverter. This set of system has functions like automatic control, on-the-spot control by hand and long-distance control.Structure and principle of variable frequency conversion constant pressure water supply control system are studied firstly, then a control method and control process of the system is given after analyzing and comparing the characteristics of several kinds of water supply systems, including Mitsubishi FX2N-32MR PLC achieves logic control, Mitsubishi FR-A500inverter achieves variable frequency drive. According to actual process requirements, the system obtains pressure feedback signals by multi-point collecting and averaging, and realizes constant control of the system through closed-loop manner. Hardware and controlling program are designed, and system’s EMC and suppressive ways are put forword. Then simulation of the system is carried on by MATLAB’s Simulink, so as to select appropriate PID parameters, and optimize static and dynamic characteristics of the system. Finally, visual interfaces of the constant pressure water supply control system is designed to improve the system’s degree of automation.The plan of variable frequency conversion constant pressure water supply control system designed by this paper has been applied to Jiangsu Xutang power Co., Ltd deep well water system. The system has stable performance and achieves the desired effect after put into operation over a year.